AR15.Com Archives
 22 magnum conversion
AR-fan  [Team Member]
4/23/2009 9:59:19 AM
I just started testing a 22 magnum conversion unit in a standard 5.56 AR. I have not had a chance to test at the range yet but due to the variety of barrel twist rates in AR's I'm not sure the accuracy will be good. I did get to test the conversion unit in a KKF dedicated 22lr (1:16) barrel and it had very good accuracy at 50 yards. with the 22lr dedicated barrel, I have a choice of shooting 22lr ammo or 22 magnum ammo depending on which conversion unit I used. I have two standard AR barrels I can test the 22 magnum conversion unit in, one is a 1:7 twist and the other is a 1:12 twist rate. This is another project to show that it can be done so maybe some company can copy it or manufacture their own version of the conversion unit –– if it works OK. I won't get a chance to check the accuracy in a standard AR barrel for another week or so. Another problem is the gas leak –– it's not really all that much but may cut the velocity down enough that it's not worth the trouble. I'll try to post some videos of the cycle tests later this week.

Edit to add 1st test of 22 magnum conversion in a standard AR-15.
After the first couple of shots I had to stop and check that all was ok –– lots of smoke! Seems it was oil still in the rifle from the last cleaning. I decided, after checking the rifle a few times during the test firing to verify that all was ok, I should try further testing in a barrel that I was not so fond of.
Alaskacajun  [Team Member]
4/25/2009 2:32:58 AM
I always wondered why there wasn't more interest in .22 mag AR conversions.... very interesting! Thanks for posting!

- Clint
AR-fan  [Team Member]
4/25/2009 9:33:02 AM
Originally Posted By Alaskacajun:
I always wondered why there wasn't more interest in .22 mag AR conversions.... very interesting! Thanks for posting!

- Clint


I think that most people, that shoot rimfire, are wanting to shoot at a discount and nothing beats 22lr for good old shooting fun. The more ammo you can easily buy the more fun you have. The problem with the 22 magnum and the 17 hmr is the cost so plinking and blasting can be done but it's a bit pricy. On the other hand there are people that use the 22 magnum or 17hmr in varmint control or fur hunting and only a few shots are necessary –– I guess I fall into this area.

I had an idea at one time about making a 22 magnum conversion for the standard AR-15 since the bullet diameter and bore size are correct. I figured it woud work for anybody with an ar-15 but I guess I was wrong. I am still going to try the setup in a more common 1:7 barrel twist to see how it affects the 22 magnum bullet. I'm beginning to think the best setup would be a 1:16 twist barrel designed to accept the chamber adapters of all 22 conversions –– these are already made. I got a KKF dedicated 22lr barrel years ago and found the 22 magnum conversion shoots great in it and I can take the magnum conversion out and switch back to shooting 22lr ammo. Maybe I should drop the idea of shooting 22 magnum in the AR barrels and switch to the dedicated 22lr barrels.
Brazos_Jack  [Member]
4/25/2009 10:17:26 AM
I would be interested in something like this if it was set up to use a dedicated barrel like Spikes dedicated uppers. Spikes sold me the dedicated barrel and modified .22LR conversion unit that they use in their dedicated uppers. I use it in my MGI switch barrel upper. No gas port, no conversion chamber to barrel gap in front of the cartridge, and proper barrel dimensions and rifling twist. If someone offered the same sort of set up in .22 WMR or .17 HMR then I would be interested.

Brazos Jack
AR-fan  [Team Member]
4/25/2009 10:54:58 AM
Originally Posted By Brazos_Jack:
I would be interested in something like this if it was set up to use a dedicated barrel like Spikes dedicated uppers. Spikes sold me the dedicated barrel and modified .22LR conversion unit that they use in their dedicated uppers. I use it in my MGI switch barrel upper. No gas port, no conversion chamber to barrel gap in front of the cartridge, and proper barrel dimensions and rifling twist. If someone offered the same sort of set up in .22 WMR or .17 HMR then I would be interested.

Brazos Jack


That might be a possibility is some company wanted to start building something like this. It would be set for their design and they would be the place to go to for a 22 magnum or 17 hmr conversion. If the 22 magnum conversion is possible the 17 HMR is not far behind!

This is the second test I did and I'm now using the KKF dedicated 22lr barrel. A chamber adapter is necessary for this particular dedicated 22lr barrel type and it fit my project just fine. Please ignore my stupid comments while I was running the test!

2nd test using KKF dedicated 22lr barrel
This is the top of the KKF barrel.


As you can see in this test there was no smoke or gas leak noticeable and the setup ran like a charm. If I wanted to shoot 22lr ammo, all I need to do is remove the 22 magnum conversion unit and insert the 22 lr conversion unit and I'm ready to go again! The next step is to check the accuracy at the range and that won't be till next week. I got to build a playset for my grandchildren.
edlmann  [Member]
4/25/2009 11:18:00 AM
Originally Posted By AR-fan:
I just started testing a 22 magnum conversion unit in a standard 5.56 AR.


What sort of a mag set up do you use?

Any pics?

Alaskacajun  [Team Member]
4/25/2009 11:59:14 AM
I thought the .22 WM was a bigger diameter than the .22 LR... like .222/.221. I realize that it's only .001, so apparently that doesn't matter to the .22 LR barrel, right?

Also, are you using a modified Ceiner BCG in that video?

This really interests me. I love tinkering with stuff like this. I don't necessarily need one either but I think it would be really cool to have. I could bring it on my trapline to dispatch wolves and wolverine.

- Clint
AR-fan  [Team Member]
4/25/2009 4:35:05 PM
Originally Posted By edlmann:
Originally Posted By AR-fan:
I just started testing a 22 magnum conversion unit in a standard 5.56 AR.


What sort of a mag set up do you use?

Any pics?


I made mags using standard Marlin 22 magnum bolt action magazines. I could put a couple together in series to make a 15 or 20 round mag but the big problem then is a good spring.

The mag on the left is a 7 round mag and the one on the right is a 20 round mag.



AR-fan  [Team Member]
4/25/2009 4:44:23 PM
Originally Posted By Alaskacajun:
I thought the .22 WM was a bigger diameter than the .22 LR... like .222/.221. I realize that it's only .001, so apparently that doesn't matter to the .22 LR barrel, right?

Also, are you using a modified Ceiner BCG in that video?

This really interests me. I love tinkering with stuff like this. I don't necessarily need one either but I think it would be really cool to have. I could bring it on my trapline to dispatch wolves and wolverine.

- Clint


It's been kinda common to rechamber a safe action from 22lr to 22 magnum if a 22 magnum is what was needed. Swaging the 22 magnum bullet from a .224 to a .223 will not cause a problem as long as all other paramaters are OK.
rjay  [Member]
4/25/2009 5:12:08 PM
I did a 22 mag conversion several years ago. I used a 1.25" dia Anschutz "match" 22lr bbl and adapted the M261 kit minus the chamber adaptor. The first time I fired it I just happened to be at the 200 yd line so I kept adding elevation until I got on paper. The first two shots on the paper were about 1/4" apart !!! At 200 yds !!!!

I still haven't started working on a magazine. Right now it goes 'bang' and ejects so I am happy.
AR-fan  [Team Member]
4/25/2009 9:02:06 PM
Originally Posted By rjay:
I did a 22 mag conversion several years ago. I used a 1.25" dia Anschutz "match" 22lr bbl and adapted the M261 kit minus the chamber adaptor. The first time I fired it I just happened to be at the 200 yd line so I kept adding elevation until I got on paper. The first two shots on the paper were about 1/4" apart !!! At 200 yds !!!!

I still haven't started working on a magazine. Right now it goes 'bang' and ejects so I am happy.


The M261 conversion unit is built like a tank and that's the reason I use it also. It's good to see somebody else has also tried the 22 magnum thing in the AR. My wife loves to shoot the other dedicated 22 magnum AR's I have because they are so accurate.
rjay  [Member]
4/25/2009 11:04:08 PM
I'm pretty sure you gave me all the info and your ingenious pushrod design. I added weight to a std buffer [ filled it with lead shot ] and did something to the spring [ that I have since forgotten ]. The coolest thing I did was go with a good bbl with the 22mag chamber and no adaptor.

Someday I will make a magazine. I would be happy with 5 rounds.

AR-fan  [Team Member]
5/1/2009 5:41:26 AM
Originally Posted By rjay:
I'm pretty sure you gave me all the info and your ingenious pushrod design. I added weight to a std buffer [ filled it with lead shot ] and did something to the spring [ that I have since forgotten ]. The coolest thing I did was go with a good bbl with the 22mag chamber and no adaptor.

Someday I will make a magazine. I would be happy with 5 rounds.

http://i114.photobucket.com/albums/n260/raayjayy/22magarchamberend-1.jpg


rjay,
I'll try to post some pics of making a magazine using the standard Marlin 7 shot 22 magnum magazine. I'd hate to leave you with a single shot. Some of the newer 22 magnum ammo would make your rifle a good huntin rifle. Give me a little time because I'll need to order the mag.

MGP  [Team Member]
5/1/2009 8:26:48 AM
Nice job but i would think a 223 barrel would work better because the 22magnum is .219" dia and a 22lr is .215"-.216" just a thought.Mike
AR-fan  [Team Member]
5/1/2009 8:05:10 PM
Originally Posted By MGP:
Nice job but i would think a 223 barrel would work better because the 22magnum is .219" dia and a 22lr is .215"-.216" just a thought.Mike


Actually, the 22 magnum bullet is .224" diameter –– and works really well going through 1:12 twist AR barrel. It also works well through a 22lr bore since it can swage down to the correct size.
rjay  [Member]
5/2/2009 7:47:42 AM
I have experimented with pulling and replacing 22mag bullets [ only in my bolt actions so far ]. I have measured a lot of 22 mag bullets and most measure .223. This is with my dial calipers and I need to check some more with an actual micrometer. I did have to polish down the dia of the pilot on the Clymer chamber reamer I used.

AR-fan  [Team Member]
5/2/2009 12:59:27 PM
Originally Posted By rjay:
I have experimented with pulling and replacing 22mag bullets [ only in my bolt actions so far ]. I have measured a lot of 22 mag bullets and most measure .223. This is with my dial calipers and I need to check some more with an actual micrometer. I did have to polish down the dia of the pilot on the Clymer chamber reamer I used.



Rjay,
Most calipers are not dead on accurate at the 3rd decimal place –– mine will show .224" bullets as .2235"! The picture below is the bullets that CCI is using in their 22 magnum V-max cartridge.

Notice the description of the bullets –– they are blems and is the only reason Midway got them but also notice that they are .224" dia. If all else fails in figuring the true diameter of the 22 magnum bullet contact Rick Sanborn, the owner of Green Mountain Barrels and he will verify that SAMMI specs for 22 magnum barrels is the same as 22 centerfire barrels –– the difference is in the twist rates.

Edit to add more info;
I went to the range and shot the 22 magnum conversion in my KKF dedicated 22lr upper –– it shot great. The only problem is my eye sight and the upper had only iron sights and no scope. My next test will be with one of those Colt clone 4x scopes attached.

This is a picture of the 22 magnum conversion unit.

It looks just like an M261 unit without the spring and guide because that is just what it is –– with a few mods. The chamber adapter is re-chambered for 22 magnum, the bolt face is opened to take the magnum rim and an operating rod has replaced the spring and guide rod. The op-rod works against a buffer and spring so the required weight can be added to the buffer to allow for the increased power of the 22 magnum. The 22 magnum conversion can be removed just like a standard unit and replaced with a 22lr conversion so the less expensive ammo can also be shot.

Edit @ 5/9/09 to add; I received the Marlin 22 magnum magazines and just put together the adapter that fits it inside an AR magazine. It's nothing fancy and doesn't need to be. I'll post pics of the parts and explain the function but right now I've got mother's Day to handle.
AR-fan  [Team Member]
5/9/2009 9:57:32 PM
rjay,
I hope this isn't too clunky looking –– I had to put this together kinda fast –– not much free time these days. You can adjust the Marlin mag to work with your setup and it should feed like a champ! I'll try to do another video using this magazine in the rifle with the 22 magnum conversion unit.

This first picture shows the 3 parts. on the left is an old mag body that was shortened –– it's not necessary, I just like some like that. The Marlin Magazine is in the middle and the "L" shaped thing on the right is the mag holder that fits into the AR magazine body.


The Marlin mag in the mag holder on the right –– notice the screw on the bottom –– it's for adjusting the hight of the mag so it fit the bolt correctly. Also note the little flaps near the top of the "L" mag holder –– they keep the front of the Marlin mag aligned.


The picture below is the Marlin mag in the holder and inserted into the AR mag body. It should not be a tight fit but not a sloppy fit either.


The picture bbelow is the top of the AR magazine body with the Marlin magazine extending out of the top. I had already adjusted the hight for my setup with that screw that is in the bottom of the "L" mag holder. All I need to do is add some blue lock-tight to that adjusting screw.


This last picture is of the bottom of the mag setup showing the adjusting screw and just to the right on the magbody can be seen a screw that holds the "L" mag holder in the AR mag body.


The "L" shaped mag holder can be made of any material, wood, plastic, etc. The whole thing can be made so it all fits in a standard size AR mag –– I just happened to have this short one available so I used it. I kinda slapped things together and that's the reason for the screw I used in the bottom –– I could have done it differently but it got the job done.

AR-fan  [Team Member]
5/12/2009 10:40:26 AM
This is a function test only of the magazine since I see no point in wasting any more good ammo. I changed the color of the mag from that tan to a green –– it's not a different magazine.
22 magnum magazine function test video
stanprophet09  [Team Member]
5/12/2009 8:34:28 PM
+1,
I have been waiting for someone to make a kit for some time. Thank you for sharing this, I may have to look into putting one together for some ground hog fun. Too populated of an area to pop off some 223, but 22 mag and 17HMR are perfect.

AR-fan  [Team Member]
5/12/2009 9:44:04 PM
Originally Posted By stanprophet09:
+1,
I have been waiting for someone to make a kit for some time. Thank you for sharing this, I may have to look into putting one together for some ground hog fun. Too populated of an area to pop off some 223, but 22 mag and 17HMR are perfect.



I have to be honest with you I have not had a real chance to test this conversion unit thing for accuracy is a GI barrel other than the 1:12 twist Pencil barrel I have. I decided to do testing with the dedicated 22lr barrel that will accept 22lr conversion units with chamber adapters because I can shoot both 22lr and the 22 magnum –– plus I'm a bit protective of the 1:12 barrel. I have a 1:7 government profile barrel laying around but I can't see a twist like that working with the 22 magnum very well. I have done a few reline projects on shot-out GI barrels and chambered them in 22 magnum and they shoot really super and are dedicated 22 magnum uppers –– but that was another of my projects –– like what "rjay" was working on. It's basically the same 22 magnum conversion unit but without the chamber adapter and (in my case) a relined GI barrel. I can post some pictures of a relined barrel 22 magnum project if you like to do stuff like that.

stanprophet09  [Team Member]
5/12/2009 10:44:21 PM
Ok I will ask a dumb question, I have no experience with the rimfire conversion. Is the chamber adapter removable? I have a feeling it would not be to keep the reliability up. I am curious to see how it does particularly in a 1-9 twist barrel, It seems the 1-16 would be better but for close range action 1-9 might be suffecent. Now on your dedicated upper, did you have the 22lr re chambered for 5.56 so the chamber adapter would work? I have limited experience at major gunsmith, but as far as doing a re-line on a barrels I believe would be beyond my capabilities. I am very interested to see the results from the kit.



AR-fan  [Team Member]
5/13/2009 5:55:21 AM
Originally Posted By stanprophet09:
Ok I will ask a dumb question, I have no experience with the rimfire conversion. Is the chamber adapter removable?
Yes, I use a modified M261 unit that's adapted to shooting 22 magnum so the whole thing, including the chamber adapter is removable.

I have a feeling it would not be to keep the reliability up. I am curious to see how it does particularly in a 1-9 twist barrel, It seems the 1-16 would be better but for close range action 1-9 might be suffecent.
I have a used GI barrel with 1:7 twist that I could try –– the 1:9 twist should work better but I won't be getting a chance to get back to the range for a few weeks.

Now on your dedicated upper, did you have the 22lr re chambered for 5.56 so the chamber adapter would work? I have limited experience at major gunsmith, but as far as doing a re-line on a barrels I believe would be beyond my capabilities. I am very interested to see the results from the kit.
On the dedicated upper that I'm using with the 22 magnum conversion unit, the barrel is a dedicated 22lr barrel that was already chambered in 5.56 and made by KKF so it would accept the chamber adapter of any conversion kit. I like to practice using an Air Force 22lr conversion unit. Relining a rifle barrel can be an expensive job unless you are planning to do more than 2 or 3. I will try to get the accuracy results and post but, again, I won't be able to get to the range for a few more weeks. I've been posting the results of my little project hoping that maybe some company would like to pick it up and run with it. I have no desire to copy right or patent it –– it's just an idea meant to be shared. Maybe it's not a item that anybody would be interested in.
AR-fan  [Team Member]
5/14/2009 10:30:12 AM
I thought maybe I should try the 1:7 twist barrel just to see how well it works against shooting 22lr. I pulled the 22lr dedicated barrel out of the original A2 upper receiver and put it into a flattop receiver so I can add a good scope. I put the Colt 1:7 (ban era) barrel in the original A2 upper receiver and slapped on a Colt clone 4X scope.


This is the markings on the barrel.


I will still test the accuracy of the KKF dedicated barrel setup and now I can also test 5.56 barreled setup. I won't be able to compare the two setups because the 5.56 barrel setup is kinda handycapped with that Chinese 4X scope. The main thing with the 5.56 barrel is, I want to see if I can get some fair accuracy and that the fast twist doesn't tear the jacket off the bullets. I've test fired the 5.56 barreled version and it works really nice so I'm hoping everything will go well. If I can get fair accuracy out of the 1:7 barrel a 1:9 should be better.
AR-fan  [Team Member]
6/6/2009 7:05:27 PM
Ok, here's the final story ––
I finally got a chance to test the 22 magnum conversion unit at the range and the unit functioned 100% but the accuracy was not what I had hoped for –– at least with the dedicated 22lr barrel I used in one of the setups. I shot CCI 22 magnum ammo and CCI 22 magnum v-max ammo, switched out the unit with an Air Force unit and then shot 22lr ammo.

The 1:7 twist setup shot just fine but the groups were on a par with what you get when shooting 22lr through a 1:7 twist AR barrel. For the cost of 22 magnum ammo it's best to stick with 22lr in this style setup. The 22lr ammo didn't do much better in this barrel.

The dedicated 22lr barrel shot a lot better but I could only get groups of 1" at 50 yards –– still not good enough for the price of ammo when a dedicated 22lr barrel with 22lr ammo should should shoot half that. The 22lr ammo shot pretty good but I expected that since I've used this barrel with the Air Force unit many times.

I have to say I feel a bit bad about how this 22 magnum conversion unit worked out. I have a true 22 magnum setup (no chamber adapter) and I can shoot 3/8" groups all day –– better with the V-max 22 magnum ammo. This makes for a good hunting rifle. If the barrels in the above setups were dedicated to just 22 magnum they would be good shooters too but I wanted to be able to switch between 22 magnum and 22lr.
Brett_Walker  [Industry Partner]
6/7/2009 10:40:21 AM


That box looks familiar, I got 5 or 10 of them when they went on sale a while back. The 22 magnum idea looks pretty neat, because it gives you another option that has considerably more poke at a considerably longer range than standard 22 lr.

I think I'll go size me up a bunch of them mass produced hollow brass chamber adaptors to put these 30 grain poly tips in. I'm just going to use a little blud dot behind them and they'll prolly come out faster than 22 mag anyways, and with just as good or better accuracy because there is no huge freebore from an adaptor.

Now if you could do a 17 HMR with a dedicated barrel and magazine options to 30 rounds or so, now I'm interested.

Looks like you've had a lot of good success and fun tinkering with old airforce junk.

Brett
eric10mm  [Team Member]
6/7/2009 12:44:53 PM
Originally Posted By AR-fan:
This is a picture of the 22 magnum conversion unit.


Firstly, COOL AS HELL!!!!!!

Regarding your conversion kit "op rod" recoil assembly. Does your setup utilize the rifle's normal recoil spring and buffer in the butt stock? I'm a little fuzzy on that aspect.

AR-fan  [Team Member]
6/7/2009 12:50:07 PM
Originally Posted By Brett_Walker:
http://img.villagephotos.com/p/2004-11/877429/22magnumbullets.jpg

That box looks familiar, I got 5 or 10 of them when they went on sale a while back. The 22 magnum idea looks pretty neat, because it gives you another option that has considerably more poke at a considerably longer range than standard 22 lr.

I think I'll go size me up a bunch of them mass produced hollow brass chamber adaptors to put these 30 grain poly tips in. I'm just going to use a little blud dot behind them and they'll prolly come out faster than 22 mag anyways, and with just as good or better accuracy because there is no huge freebore from an adaptor.

Now if you could do a 17 HMR with a dedicated barrel and magazine options to 30 rounds or so, now I'm interested.

Looks like you've had a lot of good success and fun tinkering with old airforce junk.

Brett

Brett,
I always liked the Air Force conversion unit with those mags with the real bolt-hold-open option. I have two dedicated 17HMR setups (no chamber adapters) and they both shoot really great but, again, the mags are a problem. My biggest problem is I can't make springs and the second is forming the magazine out of sheet metal. I have to use existing magazines and make them work in the AR.

The dedicated 22 magnum and the dedicated 17HMR are pretty much the same with only a slight difference in the mags. It seems I can be sloppy in making the 22 magnum magazines and they work fine but the 17 HMR's with the long pointed cartridge don't like being off a hair in the transition from the magazine to the chamber. The picture below is of the real dedicated 22 magnum AR with a side charging handle. The 17HMR is pretty much the same.

This rifle will put 5 rounds into 3/8" easy and if I try real hard (to beat my wife shooting) it will do 1/4" at 50 yards from time to time with Remington V-Max 22 magnum and CCI V-Max 22 magnum (2200 fps). I have not shot the 17HMR in a long time because the ammo is hard to find here.
AR-fan  [Team Member]
6/7/2009 12:57:41 PM
Originally Posted By eric10mm:
Originally Posted By AR-fan:
This is a picture of the 22 magnum conversion unit.
http://img.villagephotos.com/p/2004-11/877429/Mynew22magnumconversionunit.jpg


Firstly, COOL AS HELL!!!!!!

Regarding your conversion kit "op rod" recoil assembly. Does your setup utilize the rifle's normal recoil spring and buffer in the butt stock? I'm a little fuzzy on that aspect.


You are correct, although the buffer is modified and the spring is cut to allow just enough power to strip the round and close the bolt. The Op-rod sticks out a hair past the end of the unit so the bolt always has spring pressure against it. The picture below is of a newer type bolt I am trying out and it's more or less just like an AR bolt but with an M261 front end. It works really nice, uses a special length buffer and a modified spring.


All my original setups used the "Bolt and Op-rod" design and they work great but this drop-in 22 magnum conversion unit didn't turn out very well. If you look at the chamber adapter you will notice there is no "Neck" that is normally found on these adapters and I guess I screwed up using that chamber adapter –– that is how it was when I got it. I'll try sometime to get in touch with Compass Lake Engineering and see if I can buy one with the neck still in place. Maybe that will help the Drop-in conversion work in the dedicated 22lr setup I have.

eric10mm  [Team Member]
6/8/2009 10:39:57 AM
Originally Posted By AR-fan:
If you look at the chamber adapter you will notice there is no "Neck" that is normally found on these adapters and I guess I screwed up using that chamber adapter –– that is how it was when I got it. I'll try sometime to get in touch with Compass Lake Engineering and see if I can buy one with the neck still in place. Maybe that will help the Drop-in conversion work in the dedicated 22lr setup I have.


My original M261 chamber adapter also had a "neck", but it split and broke on me one day. None of the replacement chamber adapters I purchased from CLE had the neck. I've not noticed any difference firing .22lr ammo.
AR-fan  [Team Member]
6/8/2009 7:03:50 PM
Originally Posted By eric10mm:
My original M261 chamber adapter also had a "neck", but it split and broke on me one day. None of the replacement chamber adapters I purchased from CLE had the neck. I've not noticed any difference firing .22lr ammo.


I got a bunch of the M261 conversion units years ago and bought a bunch of extra chamber adapters from CLE back when they cost $5 each. I still have one good M261 and the chamber adapter in the picture was the last of the extras I had. I did notice that the necks on the extras I bought from CLE all had different length necks and, of course, this last one had none. I did this slid-in 22 magnum conversion before and used a good chamber adapter with a standard length neck and it shot good but then I screwed things up by running a throating reamer through the adapter thinking it would smooth out the transition to the barrel and make it shoot better –– the thinner neck cracked on me.

I just took the 22 magnum conversion unit apart and am now using it in a quickly put together 17 HMR rifle (dedicated barrel, no chamber adapter) but with iron sights. It looks just like the rifle in the picture minus the scope and the barrel has a front sight and a flash hider. I reused parts from one of the 22 magnum conversion test rifles since I was not pleased with the way the conversion unit worked. I have not given up on the unit yet –– just need a better chamber adapter.

I can always get a scope mounted on the carry handle but I wanted to see how this worked out for me. I've already test fired it using that 7 round mag that I showed earlier in this thread. I won't be able to check the accuracy for a while do to other projects.

AR-fan  [Team Member]
6/12/2009 6:38:47 PM
Well, I got the 17HMR test rifle all together using a gov. profile type barrel so it's a lot lighter than first 17HMR. My wife thought I was crazy trying to use the iron sights with my eyes so I decided to change the upper receiver and add a scope. Now my big problem is I can't find any 17HMR ammo so I may have to order it on line.

This is a close-up shot of the receiver showing it's the same old modified M261 bolt setup that I used in the 22 Magnum tests but this 17HMR is using a dedicated barrel with no chamber adapter so I'm hoping it's close to accuracy of my heavy 17HMR rifle.


jim  [Member]
6/12/2009 11:38:40 PM
why not pick up a take off 77/22 or 10/22 bbl, fab a bushing to sit in the upper receiver and work off that? i picked up a 77/22 bbl off rimfirecentral.com. guy fabbed up a bbl bushing and installed it onto the ruger bbl. slapped it onto aan A=3 upper and budget free float tube. that baby shoots very nice and its a dedicated bbl unit. the teist is 1/16 so your accuracy would be right where you would expect it to be
AR-fan  [Team Member]
6/13/2009 7:33:32 AM
Originally Posted By jim:
why not pick up a take off 77/22 or 10/22 bbl, fab a bushing to sit in the upper receiver and work off that? i picked up a 77/22 bbl off rimfirecentral.com. guy fabbed up a bbl bushing and installed it onto the ruger bbl. slapped it onto aan A=3 upper and budget free float tube. that baby shoots very nice and its a dedicated bbl unit. the teist is 1/16 so your accuracy would be right where you would expect it to be


That's not a bad idea and I've done it already for shooting 22lr and I used a Green Mountain fluted 10/22 barrel –– it worked really nice. I had seen somebody here on ARFCOM do it and thought it was a good idea and it was! I already have a free floated, heavy barreled 17HMR upper that shoots unbelievable. I used the type of free float tube that's used in the match service rifles so I can use standard handguards and the rifle looks like a standard AR –– except the scope!

edit to add: I just ordered some 17HMR V-Max ammo on line so I can test as soon as it gets here.
AR-fan  [Team Member]
6/19/2009 5:05:46 PM
I found a box of CCI 17HMR TNT ammo at a local Wally-World so I have something to test with. My good camera died and the second camera, for some reason, didn't record any sound. I loaded 5 rounds in the magazine and fired 1 shot, than 3 fast shots and then the final round –– all with no problems. I hope to get to the range soon to see what kind of damage I can do to a perfectly good target.
Test of 17HMR using the OP-Rod bolt setup.

Just to give you an idea of the difference between the two camera's, here is an older test, on a different lower and no handguards on the same GI profile barrel. This one has sound but I only loaded 4 rounds in the magazine –– must have been the last of my supply.
Older test of 17HMR but with sound.
AR-fan  [Team Member]
6/28/2009 8:37:33 AM
I decided to re-try something I did a long time ago –– actually attach the operating rod to the bolt. I also added a side charger handle to make it a bit easier to load off a fresh mag when I have a scope installed. The upper receiver is a piece of junk Mule receiver I use for testing stuff but it does work well.

Notice the op-rod is now part of the bolt.

This is a lot easier to do make than the one-piece AR type bolt and works just as well with the same buffer and spring!

This is the setup installed in the test receiver.

The bolt handle unscrews for easy removal of the bolt.

I guess this is the end of the story!
rjay  [Member]
7/9/2009 2:18:51 PM
I have been doing some work with my 22mag AR. I started trying to adapt an on hand Savage 93 mag. These things are made out of a 'steel' with the tensile strength of wet mud. I am going to order a Marlin mag. I am amazed your's feeds reliably with the mag so far from the chamber.

I am going to shoot my rifle in a rimfire 'Benchrest Silhouette' match in a couple of weeks. They start out at 75 meters and the rams are at 188 meters !!!! 205 yards !!!!!! The 22lr shoot in one class and everything else shoots in the '17' class which means my 22 mag will be shooting against 17HMR's. I am also going to shoot my 40x 22lr BR rifle.

In testing I had some issues with both rifles and I noticed that the adaptor for my bore brush was a bit beat up so I redid the crowns on both rifles and fixed a headspace issue on the 22 mag ar. NOTE , 19/64 end mill works perfect for a 22 mag/17hmr bolt face. The crown on the 22mag was really bad. This was the first bbl I ever fitted and I didn't have the knowledge or tools to do it right. I also didn't have the optics for inspecting the crown and bore.

With the repair work done both rifles shot much better. Wally world has some $9.99 a box CCI 40 TMJ that shoots pretty good in my rifle. The companion CCI 40gr jHP didn't perform as well. On the box it says 1875 FPS and my chrono agreed. I didn't have much trouble hitting a ram outline at 200 yds. My magazine single shot adaptor is working good. I really need a bolt mounted, LH charging knob but I don't have an upper I am willing to cut up at this time. Hmmm, lh side might be tough due to the bolt guide rail..........

I made a 3" wide glide plate and mounted it to the Hogue float tube I am using. I removed the early short stock and installed a later stock and removed the sling swivel so it would ride the bag properly. Big improvement for shooting off BR spec rests.

So far I am really happy with the Anschutz 22LR match blank I used. The bore on these things is super smooth.
AR-fan  [Team Member]
7/9/2009 8:27:22 PM
Rjay,
Sounds like you got yourself into some really nice fun. I would love to know how well you do against the 17 HMR guys. The magazine is the really strange part of the whole AR project. At first I figured I needed a ramp in front of the mag to make sure the round hit the chamber. I was in a hurry one day and left the ramp off and the mag actually fed better. The only thing I needed was that adjustment screw on the bottom to raise or lower the mag just a hair. After the correct hight (fit to the bolt) is found you can make it permanent but that's just more wasted time for me. That picture of the setup for using the Marlin mag was slapped together so it looks like crap but that just shows how really easy it actually is to make.

You're right about the left side charging handle –– I would prefer that myself. By the way, The 22 magnum rifle that I built with the full AR bolt will shoot 1/4" at 50 yards all day long with the CCI V-Max ammo that runs 2200 fps. My wife and I were kinda shocked at just how well the darn thing would shoot and do it over and over again –– with that V-max ammo. I can't say that it will work for you –– you know how rimfires are. I have a little carbine that uses the op-rod setup that I just finished and hope to test this weekend.
rjay  [Member]
7/18/2009 9:29:19 PM
Well, the silhouette match was an anti-climax as far as the AR15 goes. I shot my 40x 22lr first in the unlimited class and shot clean which I was quite happy with for my first match. The rams at 188 meters [ 205 yds !!! ] were a hoot. You pull the trigger, gun bumps you in the shoulder, wait wait wait , dink [ impact ], ram FALLS over backwards. This is with Eley Black Box subsonic match ammo. I was lucky on my bench draw. I drew bench one shooting the chickens first and progressing upwards to pigs, turkeys and rams. I already had a decent idea on the scope clicks and by the end of the match I had everything really nailed down.

The guy I was paired up with was shooting a 17 HMR Anschutz. Watching his hits through the spotting scope was pretty amazing. Much louder bang from the gun, the bullet gets there much quicker and the silhouette's are knocked down with alacrity. He was getting sold center hits in conditions I would have been waiting out with my 22lr.

After the first match was completed I signed up for the next match with my AR/22mag. Due to some miscommunication I was at first told I couldn't shoot the FMJ so I changed back to the 40x in the Benchrest scope class. Then we figured out they thought I had a 17HMR bbl on my AR instead of the 22 mag. 22mag FMJ is ok, 17HMR FMJ no go as it damages the silhouettes. It would have delayed the match for me to reset so I just shot the 40x which I was fine with. I shot clean again. My scope click notes were basically perfect.

Next match I will shoot the AR and report in. We will see if it holds it's own against the 17 HMR's. I think they are in for a surprise.

One additional note. I was very surprised that there were NO SEMI-AUTOS. I would have thought the tricked out 10/22's would have been out in force. For silhouette you don't need the ultimate in accuracy so a semi should be able to be competitive.

Later
Ray
AR-fan  [Team Member]
7/18/2009 11:32:32 PM
Ray,
Do you have a magazine for your 22 magnum AR setup? If not, would you like to try that adjustable one I made?

Charlie
rjay  [Member]
7/19/2009 9:36:19 AM
Charlie,
I ordered $400 worth of stuff from Midway last week and $20 of that was a Marlin magazine for my AR. I will make up an adaptor soon. Thanks for the offer.

I also got a pair of 17 reamers. One HM2 and one HMR. The guys at the match said that the HM2 will not knock over the rams but it would be fun trying until I use up the 550 rounds of HM2 ammo I bought. I wonder if you hit the ram up in the horn if the HM2 would knock it down ???? That WOULD be a challenge !!!!! I have an Anschutz 64 action that I am going to use for my 17 experiments. I will open the bolt face to 22 mag dia when I get ready to go to the HMR.

The current project is 'accurizing' the Anschutz action. I threaded it a couple of years ago but did a 'factory quality' job and it has about .020" of runout when mounted to a bbl. This is measured on a tight fitting mandrel sticking out the back of the action so the actual correction is well under .010" up at the threads. I still have to make the bushing for the outside of the front rec ring for the steady rest to bear on. Then I can true up the threads [ or hopefully not screw up the threads ]. I have a 17 cal Wilson blank coming.

Later
Ray
AR-fan  [Team Member]
7/19/2009 2:05:05 PM
Ray,
Good to know you're going to do your own 22 magnum mags. The mags make all the difference in the AR. Sounds like you like to do your own thing when it comes to firearms –– it's a really nice hobby for me. The picture below is my new project –– a gas operated FN5.7X28 AR-15. It uses the FN 20 round pistol mags.


This target was when I started to sight in –– the round to the left is the first shot and I don't know why it did that maybe some #9 solvent still in the bore. the 4 rounds to the right represent how the rifle shoots. I built the rifle to have something just a little hotter than the 22 magnum but in the velocity range of the 17HMR and also be reloadable. The rifle will do 2600fps when I use 30gr bullets. It can do better but I want to save the brass.


Charlie
762sniper  [Member]
7/25/2009 4:49:25 PM
So, If I wanted a 22 mag AR upper ar what would be the best way to go about getting one?

I would like it in a 16" M4 type configuration for short to mid range use.

any help would be great


Thanks

Will
AR-fan  [Team Member]
7/25/2009 5:18:21 PM
Originally Posted By 762sniper:
So, If I wanted a 22 mag AR upper ar what would be the best way to go about getting one?

I would like it in a 16" M4 type configuration for short to mid range use.

any help would be great


Thanks

Will


Will,
I was kinda hoping some company would think this was an easy conversion and start making them. I have no desire to hold any rights to the idea I wanted to make it a public thing but I guess it went over like a lead balloon. I don't manufacture anything so I just make these things for myself. Rjay, another fellow here on ARFCOM, has started making his own and is in the process of making his own mags. If you're kinda good at making stuff you can build your own upper. To start you would need an M261 conversion unit, and an upper receiver. The barrel can be done by relining or have a gun smith turn a barrel for you. It's like building your own 22lr upper but with a few added modifications.

762sniper  [Member]
7/25/2009 6:22:34 PM
Originally Posted By AR-fan:
Originally Posted By 762sniper:
So, If I wanted a 22 mag AR upper ar what would be the best way to go about getting one?

I would like it in a 16" M4 type configuration for short to mid range use.

any help would be great


Thanks

Will


Will,
I was kinda hoping some company would think this was an easy conversion and start making them. I have no desire to hold any rights to the idea I wanted to make it a public thing but I guess it went over like a lead balloon. I don't manufacture anything so I just make these things for myself. Rjay, another fellow here on ARFCOM, has started making his own and is in the process of making his own mags. If you're kinda good at making stuff you can build your own upper. To start you would need an M261 conversion unit, and an upper receiver. The barrel can be done by relining or have a gun smith turn a barrel for you. It's like building your own 22lr upper but with a few added modifications.




Ok, I'm a do-it-yourselfer

Can we start with the M261 unit. where do i find one of those.

Does the system use the AR direct gas system to cycle the action or is it just blow back.

Thanks for the help

Will



AR-fan  [Team Member]
7/25/2009 9:36:53 PM
Originally Posted By 762sniper:

Ok, I'm a do-it-yourselfer

Can we start with the M261 unit. where do i find one of those.

Does the system use the AR direct gas system to cycle the action or is it just blow back.

Thanks for the help

Will


The system is a blowback. I believe you can still get an M261 conversion unit from Olympic Arms. Oly talks about it on their site but you might want to go the direct route and e-mail them to see if they still sell them. Once and a while the M261's show up in the EE.

Charlie

762sniper  [Member]
7/26/2009 8:32:11 AM
Great thank,

One more, maybe two ? (for now lol)

What would be the best twist for a dedicated 22 mag and can you get an AR barrel in that twist or do you have to make one up?

Thanks again

Will
AR-fan  [Team Member]
7/26/2009 10:05:18 AM
Originally Posted By 762sniper:
Great thank,

One more, maybe two ? (for now lol)

What would be the best twist for a dedicated 22 mag and can you get an AR barrel in that twist or do you have to make one up?

Thanks again

Will


Will,
I made mine using a bored out AR barrel and relining it with a 22lr liner I bought from Brownells. I've made a lot of rifles using this technique but if you are only doing one barrel (and you want a specific type of barrel) it may be more cost affective to have a true 22 magnum barrel made. The standard twist rate for 22 magnum is 1:14.
762sniper  [Member]
7/26/2009 1:37:41 PM
OK, thanks again.
rjay  [Member]
8/15/2009 8:21:20 PM
OK, I finally have a match report from the Extreme Rimfire Silhouette match. I missed one ram and ran into time difficulties and only got to try for 2 of the 188 meter tiebreaker targets both of which I missed so my score was 39-0x which ain't gonna win. Needed a 40 with at least 3 tiebreakers. I was really wanting to shoot a 40 but that one ram I barely ticked him low.

Other than that disappointment the rifle did very well. I still haven't made a magazine so I was having to single load which slowed me down. I also had to use a block of wood under the rear bag which made the gun ackward to address which sucks up time. The std weight RRA 2 stage trigger also slows you down compared to the 1.5 oz Jewels I have on my BR guns. I didn't have the scope turret clicks fully nailed down and had to fire more sighters to refine the POI.

I also had a bit of a learning curve with a new long travel windage adjustable rest top I made last week. I didn't fully rewind it for the rams and I ran out of travel right at the end which contributed to me running out of time. The rams are so big that the 10 target bank is really wide and I only reset the windage knob about 1/2 way which was fine for the pigs and turkeys but not enough for the rams.

I did have one FTE and I wonder if that was on the ram that didn't go down ????? Can't really say for sure. Otherwise the gun shot well, was very accurate and needed a big plywood brass deflector put up to protect the innocent. The muzzle blast and higher noise level makes the subsonic 22lr's seem like popguns If I get 2 or 3 reliable mags built I may give the AR one more shot at a win before I build me a mag bolt face bolt action benchrest rifle. I will get the results in a couple of days and post them.
AR-fan  [Team Member]
8/16/2009 8:39:38 AM
rjay,
I'm glad to see you're still working on your 22 mag AR project. I think you will like the rifle even more when you get the magazines together and working. I'm not sure what type of ammo is needed for the shooting you are doing –– what seems to work best for you?