I have been doing some research about a dedicated 17HMR upper for ARs, and I haven't found anything "over the counter,"  even high capacity mags elude me.

I contacted a few manufacturers to see if they would be willing but there is a lot of work to make the conversion work.  

Basically I am looking to get a 17HMR AR barrel, modify a cliener by turning off the chamber adapter, modify the cliener 22lr mag to a 22WMR mag (need to locate a 22WMR high-cap mag), then finally mess with the lenght of bolt travel and spring tension.  I am willing to take a chance by purchasing the barrel and the modified cliener and work out the other details as I go along.

Anyone took on this challange yet?
Any info from you guys?

Quoted: I have been doing some research about a dedicated 17HMR upper for ARs, and I haven't found anything "over the counter,"  even high capacity mags elude me. I contacted a few manufacturers to see if they would be willing but there is a lot of work to make the conversion work.   Basically I am looking to get a 17HMR AR barrel, modify a cliener by turning off the chamber adapter, modify the cliener 22lr mag to a 22WMR mag (need to locate a 22WMR high-cap mag), then finally mess with the lenght of bolt travel and spring tension.  I am willing to take a chance by purchasing the barrel and the modified cliener and work out the other details as I go along. Anyone took on this challange yet? Any info from you guys?

I've got 2 uppers in .22 magnum and one in .17HMR. At first, all I could find for magazines was the Marlin 7 round magazine. With a little work the mags can be connected in series and a magazine follower designed similar to the Ciener mag follower to get a good 15 round magazine. The 22 magnum is not hard to work with, pressure wise, but the .17 HMR is a real pain and if you are not careful in the bolt head design and head space, it will cause rim seperation and blow the crap out of the magazine. This is one reason Ruger has not come out with the 10/17 they showed back in 2004. I have not tried using the Ciener setup for either the 22 magnum or the .17HMR because of their cost and because the bolt is a bit lighter than the M261, which is what I use. I have used the Ciener for the .17 Mach2 but it requires a modification that allows the Ciener bolt to push against a modified AR buffer so that more weight can be added as needed. The M261 bolt doesn't require this.

The 22 magnum uppers are really my favorites -- one is a 16" carbine and the other is a 20" government profile barrel setup. I didn't want to go to the expense of having a custom barrel made just to find out that I couldn't get the darn things to work so I did it by relining GI barrels. Since I already had the equipment to do the relining I did all of the 22 magnums and the 17 HMR for the price of one custom barrel.

AR-Fan,

Thanks for the reply.  

I don't have a ciener kit to look at but Kurt Kustoms said their conversions (22lr) are based on the ciener, so I figure it would be easier for him to make a barrel to match what he is most familiar with.

I do have a M261, and with a little mod to the charging handle, I think I can add another 3/16-1/4 stroke to the bolt that should make up the extra length of a 22WMR or 17HMR,

What exactly did you do?
From what I can think of:
You drilled the chamber adapter for 22mag
You stacked two Marlin 7 to get 15 rounds. (I just ordered 1 each of the Rem, Marlin, and one other manufacturer to look at.)

Question:
What mods did you have to do to get the 17HMR to work right?
Since you made it work, a custom barrel would be possible, right?

I am thinking of removing the chamber adapter of the M261 and having the bolt butt to the custom barrel, would this be a problem?  If I remove the chamber adapter, the only thing that holds the bolt in place is the spring/spring guide, as the slide rod isn't attached to the bolt.  

I am thinking that I would have to machine a slot in the slide bar to pin the bolt to the slide bar so it wont be loose in the AR upper.

I didn't check to see if you replied -- sorry!

I used an M261 unit because it will allow the Marlin magazines to fit up where the bolt can pick up a round. There are some good points and bad points with the Ciener and I didn't try one of those -- yet.

What did I do!
I used a barrel liner so the chamber adapter is dirlled out just like the GI barrel and the liner is installed in the adapter. This goes for both the 22 magnum and the .17 HMR. A custom barrel could be made with a breach face that is the same as the M261 chamber adapter face.

The bolt of the M261 is very modified to allow it to pick up the round off the Marlin magazine.
1. A way was devised to add weight to the bolt.
2. Move the ejector back to fit the cartridges.
3. The rear block on the M261 is shortened to allow the bolt to move further to the rear.
4. The cartridge pickup rail on the bottom of the bolt is very modified to allow it to work with the marlin mags.
There is much more to it and you will spend time making adjustments to get it all to work together. The 22 magnum is much easier to work with.

Here yah go buddy .17hmr factory upper. No BS or making it!
http://www.olyarms.com/?page=m1_2217partner
Can be .22 or .17
It was a simple 30second search.

Quoted: Here yah go buddy .17hmr factory upper. No BS or making it! http://www.olyarms.com/?page=m1_2217partner Can be .22 or .17 It was a simple 30second search.

Chopper,
    Thanks for the info! That's not a .17 HMR upper setup -- it's a .17 Mach2 upper setup that Oly is selling along with one for 22lr.

Yep, already been to Oly's site.  I also called and asked if they would change the upper and they said they will, but I decided not to go with Oly and stay on tract with a 17HMR conversion.

The conversion is in the process now......

More to follow as the project progresses.

Will it blow up or will it work????

Quoted: The conversion is in the process now...... More to follow as the project progresses. Will it blow up or will it work????

Best of luck on your upper -- both the 22 magnum and the 17 HMR make really nice shooters.

I've got both a rifle length upper in the .17 HMR and a carbine now that can shoot both the 22 magnum or the 17 HMR by switching the liners similar to what Oly did for the 22lr and .17 Mach2.

The 22 magnum is my favorite due to the fact I can get cheap ammo compared to the .17 HMR.

Thanks, AR-Fan.

Your the only member that I know who has a 17HMR upper......

I wanted to stay away from sleeves so I went with a dedicated 17HMR barrel.

Quoted: Thanks, AR-Fan. Your the only member that I know who has a 17HMR upper...... I wanted to stay away from sleeves so I went with a dedicated 17HMR barrel.

That's a better way to go since the Redman liners in .17 caliber are tight and may cause more of a pressure peak. I went with the liner because it was cheaper for me to do it that way. I had nothing to go on as far as building either a 22 magnum upper or the .17 HMR upper and if it didn't work I could always use the drilled out GI barrel for something else. As it turned out I have two rifle length uppers, one in 17 HMR and one in 22 magnum and I have the carbine that is designed to let me slide the barrel liners in and out so I can change calibers. I have one set of liners for 22lr and 17 Mach2 and another set of liners in 17 HMR and 22 magnum for the carbine. Of course the bolts for the smaller cartridges are different from the bolts for the bigger stuff!

By the way, when you get everything working in .17 HMR the 22 magnum is only a barrel away!Keep us updated on your build.