I get a emails almost daily with  .45 conversion questions so here is a .45 conversion guide that shows current options and some options still in the research stage.

Olympic Arms makes the only factory .45 upper. They use a standard AR15 lower with a .45 Uzi mag with a magwell filler block welded to the back of the mag. Mags are limited to 10 or 16 rounds and Oly is currently experiencing a lack of mags for the .45 conversion.



CAV ARMS makes a polymer lower from #6 Nylon called a MKII. It is a dual use lower as it can take regular AR mags or grease gun mags. The magwell is molded wider in the middle to accomodate the grease gun mag. This lower does require the use of a HAHN magwell block and is the only block designed to work with the CAV ARMS lower. Experience has shown that a heavier buffer is needed for use in the CAV ARMS .45 conversion to prevent premature failure of the lower. SLASH makes heavy buffers for this receiver.



Bazooka Bros make a modified AR lower that uses modified grease gun mags. The grease gun mags need a new mag catch slot machined into the left side of the mag. They made improvements to their lower by adding a flared magwell. This is a picture of the earlyier version.



A company called LaFrance makes a .45 Carbine that uses Thompson mags but they are available to law enforcement and military only.



The following are .45 conversion options not yet on the market.

Tango Chaser Tactical is in the process of getting the AR45 lower to market. It is a new lower made from billet that is a dedicated grease gun lower designed to use the Oly .45 upper. It uses unmodified grease gun mags.





The big problem with .45 conversions is the lack of high capacity mags that will fit into the regular AR magwell. There just aren't any.

One option that works with some minor tweaking is the use of 9mm Sten mags. They hold 15-16 rounds of .45 but HP or flat tip bullets must be used as full length 230gr bullets are too long to fit into the Sten mag. The feed lips must be opened up to accomodate the .45 round.

I experimented with .45 GAP conversion using a modified Thompson SMG barrel. It was designed to use Sten mag also. I had a few failures to extract that I believe are due to the thicker base on the .45 GAP brass. The conversion works but need more R&D to eliminate the FTE issue.

I also made a working prototype using Reising SMG mags in a regular lower by squeezing the mags in a vice. I used JB Weld to make a dedicated Reising mag lower. The prototype works great but the mags are very expensive running from $60-$100.

If there are more options out there that I forgot to mention, please feel free to include them and feel free to correct any mistakes I may have made with the information listed.

I apologize for stealing a few pictures but pictures say a 1000 words.

Tango,
Thanks for the posting.

tag

Great info

A cursory check on wikipedia revealed that La France Specialties was acquired by Surefire (the selfsame people what make our favorite flashlights, as far as Wikipedia knows) in 2004. Maybe we could bug them (and La France specifically) to put civvie lowers/guns on the market? Maybe they just think there's no market for a .45 AR.

~GnSx
ETA: The AR-45 looks HOT.

This is only slightly off topic, but what magazines did the 9mm M3s (the ones dropped into France, specifically) use?  I'm thinking MP38/MP40 (and thus STEN) would be the smart thing, since the Resistance could be expected to capture those magazines...

In any case, (and back on topic), does TANGOCHASER Tactical have a timeline for going to market with the dedicated Greasegun AR lower?  (Hoping that it's soon!)

Right now it looks like late January the AR45 lowers will be ready for sale.

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Quoted: I get a emails almost daily with  .45 conversion questions so here is a .45 conversion guide that shows current options and some options still in the research stage.

Looks like you can about add MGI to that list:  www.ar15.com/forums/topic.html?b=3&f=124&t=299092&page=6

Quoted: Quoted: I get a emails almost daily with  .45 conversion questions so here is a .45 conversion guide that shows current options and some options still in the research stage. Looks like you can about add MGI to that list:  Link to MGI thread

Made it live for you

Quoted: Right now it looks like late January the AR45 lowers will be ready for sale.

That sounds like good news. Any Idea what the price will be on these?

$300 for a stripped lower with the mag release assy included. We are going with 7075 instead of 6061. Cost is a little more but a better material.

Quoted: $300 for a stripped lower with the mag release assy included. We are going with 7075 instead of 6061. Cost is a little more but a better material.

Thanks. I'm ready and waiting!

The mag loader is absolutely essential. I've never been able to load anywhere near a full mag with just my fingers.

Quoted: Olympic Arms makes the only factory .45 upper. They use a standard AR15 lower with a .45 Uzi mag with a magwell filler block welded to the back of the mag. Mags are limited to 10 or 16 rounds and Oly is currently experiencing a lack of mags for the .45 conversion..

Why only 10 or 16?

How many rounds will your unmod grease gun mags hold?

Does Oly sell just the uppers on their own?

I am very interested in your dedicated lower.  Where will be the best place to look for your announcment when you bring them to market?

Thanks!!

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Quoted: $300 for a stripped lower with the mag release assy included. We are going with 7075 instead of 6061. Cost is a little more but a better material.

I start shopping for grease gun mags TODAY!  The above is excellet news.  I wonder how much work it would take do drop a RDIAS in the TANGOCHASER lower...

I couldn't wait. I ordered a 10% AR45 lower. I'll have some machining to do over Christmas break.

:}

Quoted: They use a standard AR15 lower with a .45 Uzi mag with a magwell filler block welded to the back of the mag. Mags are limited to 10 or 16 rounds and Oly is currently experiencing a lack of mags for the .45 conversion. Why only 10 or 16? How many rounds will your unmod grease gun mags hold? Does Oly sell just the uppers on their own? I am very interested in your dedicated lower. Where will be the best place to look for your announcment when you bring them to market? Thanks!!

The .45 Uzi mags Oly was using for their .45 conversion are single stack and 10 or 16 rounds is all that will fit in the mag depending whether it is the preban or post ban mag.

Unmodified GG mags hold 30 rounds. I am working on a 15 and 20 round cut down version that should be available after Christmas. The 30rd mag is great but does stick out aways.

Oly is the only maker of .45 uppers right now. Demand dropped off after they ran out of mags as there were no good alternatives. Olympic Arms makes the only factory .45 upper and they do sell the separately for $594 retail.

I intend to announce the availability here on ARFCOM pending a decision by ARFCOM staff on advertising.

Ah I see.  Thanks.  I look forward to your announcement!!

I am waiting for one of TC's AR45 lowers, but i was wondering if anybody knows what the optimum barrel length for a 45ACP  would be.
I don't want the full length 16" and if I SBR it, would something a bit longer than the 6.5" k23p be any better?

I have seen discussion of 9mm velocity out of carbine barrels; the idea that out past the 5 inches or so of normal pistol barrel length the powder has (by design) completly burned and you get very little velocity gain.  I haven't see anyone I trust on the board actually talk about a chrono-verified test of this idea.  Obviously the same idea applies to .45, and it would be great to find out if there is data out there.

Currently Olympic Arms is out of complete uppers in all calibers. They do have barrels, bolt carrier assemblies, and ejector assemblies. I built a jig that allows me to drill any upper receiver for use with the Oly pistol caliber ejector assembly. I can convert any customer supplied upper receiver for a nominal fee and a 1-2 day turn around time. I can also build complete receivers, that is until Oly runs out of .45 parts. IM me for details.

Quoted: I have seen discussion of 9mm velocity out of carbine barrels; the idea that out past the 5 inches or so of normal pistol barrel length the powder has (by design) completly burned and you get very little velocity gain.

I would think that velocity would increase as long as the rifling drag on the bullet is less than the pressure times the bullet base area.  There is still plenty of barrel pressure behind the bullet even when the powder has stopped burning.

Like an air rifle.

Quoted: Quoted: I have seen discussion of 9mm velocity out of carbine barrels; the idea that out past the 5 inches or so of normal pistol barrel length the powder has (by design) completly burned and you get very little velocity gain. I would think that velocity would increase as long as the rifling drag on the bullet is less than the pressure times the bullet base area.  There is still plenty of barrel pressure behind the bullet even when the powder has stopped burning.

The key being the pressure on the base being more than the rifling drag.  In the same caliber, heavier bullets are generally longer and have more surface area contacting the rifling.  There has been ballistics software data posted showing that a few 147gr 9mm loads, with faster burning powders, will start to slow down before reaching the muzzle of a 16" barrel.

BTT for smoking cool thread.
Oly: We need more 45 Uppers!!!

You may already be aware, but the simunitions M4 uppers used by the .mil are Oly pattern.  Why does this matter?  Because the ones I handled were flat top Colt M4 uppers.  Some had the Oly-style spring kit, others had some metal tab attached to the barrel extension that performed the same function as the Oly spring.

If "someone" could find a source of worn out Sim uppers, you might be able to lay hands on inexpensive flat tops.

Good to know about your Jig though...  I'm left handed so I've always preferred the Colt pattern over the Oly pattern for the extra "face blast" protection.

great post.


Thanks

Josh Nelson,

I got your email but your email address keeps getting kicked bacK. IM me instead of emailing me and see if that works.

Tango, I have a question for you. Would it be somehow possible for you to make a .45 ACP AR that takes GLOCK 30 and 21 Mags??? Olympic makes ARs thAT TAKE GLOCK 9MM and 40 cal mags, but they don't make one in .45. That's one I'd like to see on the market.

A Glock .45 lower is next on the horizon after we get the AR45 to market. The Glock .45 mags are as wide as the mag body of the GG mag not counting the double thick reinforcement at the top of the mag. They physically will fit but we have to figure out the correct angle for the mag. I don't think it needs to be as radical as the Glock pistol grip due to the feed cone on the Oly barrel extension. We should be able to straighten it out a little so it doesn't point back at the shooter so much.

I already hit up the AR45 manufacturer about redesigning the magwell for a Glock .45 mag.

For those of you looking for Oly .45 uppers, try this company. He says he usually has uppers and parts in stock. www.jsgunparts.com

I'm out of parts and will have to order parts for a custom upper.

I don't want to sound whorish or bitter,but I listed a reasonably priced/MINT complete Oly .45 upper in the equipment exchange with 2 mags a few days ago and didn't get ONE inquiry on it! Not even ONE tirekicker or picturecollector! Who even sells these anymore? It's on Gunbroker now.

I think buyers are leary about spending money on a .45 upper until they see the AR45 lower on the market. Also, Oly's complete .45 uppers aint cheap. All the parts are proprietary so it's difficult to put one together on piece at a time.

I also suspect you can't seem to sell it because flat top upper receivers and threaded barrels are the current options in vogue.

Any SHOT show news on the AR45?

It would be good if mine didn't hit my VISA bill until February..

We weren't able to get the prototype to the SHOT Show. Our plans fell through too close to the show to get a back up plan. Still looking at a March release date.

I just got an eMail from Roger at Oly.
No K23P in 45 ACP will be made.

I hope that I can still get a bolt/carrier and extractor from them.
Then will have to have a custom barrel made.

Sorry if the K23P info is old news, i just found out.

I just got an eMail from Roger at Oly. No K23P in 45 ACP will be made. I hope that I can still get a bolt/carrier and extractor from them. Then will have to have a custom barrel made. Sorry if the K23P info is old news, i just found out.

I got conflicting info from Tom at Oly. He said they offered .45 barrels in an 8" length.

You have 2 options on a pistol barrel.

Option 1. Buy a regular Oly .45 barrel in the 11.5/5.5" FS length or the 16" length and have it cut to the length of your choice.

Option 2.  I made a custom barrel extension that allowed the use of a Thompson SMG barrel. It ran like a raped ape. The Thompson barrels can be had in a 10" or 16" length and are over $100 cheaper than an Oly barrel. The cost of the barrel extension is the issue. I will get more made in the very near future and see if I can get the price below that of an Oly barrel. The only issue with the Thompson barrels is you have to use a FF HG as there is a funky taper right where the front sight base would normally go. You can have this barrel cut down and spend less than cutting down an Oly barrel.

Here are some pictures of the Thompson barrel set up I made. I had the barrel extension made to use an unmodified Thompson barrel.

I need to make some corrections to information I previously posted. I did not intend to mislead anyone, I just misunderstood or read into information I received from Tom at Oly in our email traffic. I received an email from Tom at Oly with the following corrections:

1. 45 ACP converted Uzi mags used on the Oly conversions are not single stack mags. They are staggered magazines as they were originally designed by Uzi, although they do feed from the center as you know. They are 16 round capacity, again, because that’s how Uzi made them. (I was guessing as I've never seen a .45 Uzi mag).


2. And this one is most important: We are NOT out of all pistol caliber uppers. Pistol cal uppers are shipping all the time. Matter of fact, we shipped a K45 complete gun just yesterday! We simply do not have them on the shelf, as they are built to order. I’m not sure where you gathered this information. I even went back to our emails and did not see anything in my responses that might lead you to believe we are out of all pistol call uppers. I’m fairly certain there is some sort of miscommunications between us, but I can so nowhere were this might have occurred. We are, and will be until the newly designed magazine is released, out of magazines for the  45’s, and 10mm versions. We actually have some 40 cal mags (10 rounders) on the shelf.
To reiterate: We are NOT out of pistol cal uppers. We have the ability to assemble and ship any of our pistol caliber uppers or guns, but currently do not have mags for the 45’s and 10mm versions. Prices have not changed.


This is good news and again, I'm sorry for any misleading information I posted before.

Tangochaser: In support of your post,

We are out of mags for 40, 45 and 10mm, but can build and ship 9mm uppers with hi cap mags, and all other calbers with no mags typically within 1-2 weeks.

This is very good news. I feel lots better. And I am excited again for the AR45 release!

I have what may be a stupid question as I don't know anything about Uzi's or their mags,but I do have an Oly .45acp upper (for sale,as I don't have any free time to use it anymore).I purchased it new from an Oly dealer (not Oly direct) with what I was told were (1) 10 round mag and (1) 15 round mag (which happens to be my states legal limit).I only took it to the range once,and only loaded 4 or 5 rounds into each mag at a time,I never loaded either until they bottomed-out.Both mags fit into magwell perfectly and both functioned flawless.The .45 rounds fit into mag perfectly....but here's where the confusion comes in.Both mags are stamped ".45ACP" (and one is stamped "IMI ISRAEL").The "ten" round mag is 5.5" long and the lowest "peep" slot on side of mag is marked "10".The "fifteen" round mag is 6.25" long and lowest "peep" slot is marked "15".After seeing someone else on Gunbroker selling a 16 round mag,which looks just like my mags,but looks to be 1.5 times longer,I loaded mine all the way up this morning.The "ten" rounder holds SIX rounds,and the "fifteen" rounder holds TEN rounds only.Are these 9mm mags that Olympic restamped ".45ACP"? I'd like to be clear on this in case anyone asks why I edited my auction listing from "one ten and one fifteen round mag" to "one six and one ten round mag".Thanks.

The .45 ACP mags are factory original .45 mags. They are not restamped 9mm mags. I don't have an answer for the discrepancy in the actual round count vs what is marked on the mag. The long .45 Uzi mags you see on occassion hold 16 rounds.

Thanks for reply.I pulled them both apart and neither are "blocked".I guess I need to contact Olympic to ask why MY mags are marked one way,but load ANOTHER way.

Quoted: The "fifteen" round mag is 6.25" long and lowest "peep" slot is marked "15"..

My 16 round mags are 8.5 inches long and are marked 16 at the last hole. I saw your add and noticed that they looked different. I'm Not sure what you have. It is very difficult to get 16 rounds in mine but it can be done.

Joe

could be converted from 41AE mags.  

Will the AR45 lower work with with a 10mm oly upper?
I know this is a weird question but I'm looking for a reason to finally buy a 10mm oly upper. If I can feed it from more normal mags, I might order one tomarrow!
Thanks in advance.

Yes, the AR45 will work with an Oly 10mm upper. Someone else here on arfcom, modified GG mags for 10mm.

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Quoted: Yes, the AR45 will work with an Oly 10mm upper. Someone else here on arfcom, modified GG mags for 10mm.

Now I await the lower comming to market...htDamb you tangochaser!!! My wallet is screaming in pain!!!

Can anyone who owns an Oly 45 upper tell me what the diameter of the barrel is forward of the front sight block?  On the regular barrel not the CAR.  
Also what is the thread pitch on the muzzle - ETA: I found this elsewhere - 5/8 x 24.

Thanks
Jeff

Tango,

Thank you for starting this thread.  I have a question(s) about the Oly upper and/or 45 conversions in general.  Magazine issues aside, is it possible to put the Oly parts for the conversion in a standard AR upper.  I am totally ignorant, but very much interested in the possibilities for my first generation MGI QCB.  

There is obviously the barrel.  How do things work, from the extension on back?  I apologize if I am stepping on your thread, or asking inappropriate questions, it is just that the title of your thread suggests to me that you want to help those of us in the dark.

Thanks,

Craig

Yes you can use any upper receiver after drilling a couple of holes. The only Oly specific part is the ejector assembly that is mounted in the upper receiver. I made a jig so I can drill any upper receiver and install the Oly ejector.

I personally like to use RRA 9mm upper receivers as they do not have a forward assist or a shell deflector. Neither is needed for a .45 conversion.