10mm Auto AR build

[TTv2]

Been thinking about building one of these for a while. Currently have plans to do a 9mm 10 inch pistol build, but for 10mm I think a 16 inch barrel gets the most out of the cartridge, especially when loaded to max pressures.

Anyone here ever built a 10mm AR? Who makes 10mm chambered barrels? Looking to use Glock 20 mags, does anyone make a lower that is compatible with Glock 20 mags?

My plan for the 9mm build was to use a standard Anderson lower and the Stern Defense adapter as I would rather have a standard lower that could also go back to shooting 5.56 or some other rifle cartridge. To my knowledge, the Stern Defense adapter and other adapters only work with the 9mm Glock mags. Are there mag well adapters that will work with the larger 10mm Glock mags?

Bottom line is if I can't get a lower to use Glock 20 mags, I'm not bothering with building a 10mm AR.

PS. Also, 9mm AR's don't require a gas tube as they are straight blowback actions. Are 10mm AR's blowback like the 9's are?

 

[TTv2]

Anybody? I found lowers for the 10mm and .45 ACP Glock mags, but they're crazy expensive, like $300.

 

[rbernie]

I have NFA (New Frontier Armory) dedicated Glock lowers for 45/10mm and for 9/40S&W. I seem to recall that they were around $150 on sale; normally around $170.

https://www.newfrontierarmory.com/shop/c-45-billet-lower/

I bought all of the necessary specialty bits (barrels, bolts, and stripped receivers) from NFA and used regular ol' AR-15 stuff for everything else. I have three uppers; 9mm, 10mm, and 45ACP. The 9mm stays together all the time, but the 10mm and 45ACP uppers share the lower.

My 9mm build was flawless from the start, but it took me a bit of work to get the 45ACP carbine to feed reliably and I -still- have feed issues with the 10mm upper.

 

[MachIVshooter]

Been thinking about building one of these for a while. Currently have plans to do a 9mm 10 inch pistol build, but for 10mm I think a 16 inch barrel gets the most out of the cartridge, especially when loaded to max pressures.

Your gains beyond 8"-10" will be very minimal; Yes, it's a high pressure cartridge, but it still doesn't use that much powder, nor does it use the slow magnum powders behind heavy bullets that benefit cartridges such as .44 mag in long barrels.

As for parts, I'll just say best of luck. I've seen considerable feeding issues with every Glock mag 10mm build attempted by the shops I smith for. I've taken steps to correct the problems with modifications to mags, feed ramps and bolt faces, but they are still fickle critters.

I did a build for myself in 10mm Magnum, but that's a whole 'nother ball game, being gas operated with a longer, more powerful cartridge and feeding from modified 5.56 mags

 

[WestKentucky]

I had the money, I had the desire, the horror stories ran me away. Unreliable is unacceptable, and it seems to just be that way. If I were to try a 10at this point I think I would find a way to use a different mag, even if it came down to using a 1911 mag.

 

[TTv2]

Your gains beyond 8"-10" will be very minimal; Yes, it's a high pressure cartridge, but it still doesn't use that much powder, nor does it use the slow magnum powders behind heavy bullets that benefit cartridges such as .44 mag in long barrels.

As for parts, I'll just say best of luck. I've seen considerable feeding issues with every Glock mag 10mm build attempted by the shops I smith for. I've taken steps to correct the problems with modifications to mags, feed ramps and bolt faces, but they are still fickle critters.

I did a build for myself in 10mm Magnum, but that's a whole 'nother ball game, being gas operated with a longer, more powerful cartridge and feeding from modified 5.56 mags

I had the money, I had the desire, the horror stories ran me away. Unreliable is unacceptable, and it seems to just be that way. If I were to try a 10at this point I think I would find a way to use a different mag, even if it came down to using a 1911 mag.

Well that's not good news. That's okay, given how pricey it appears the 10mm AR lowers are, I think I'm better off waiting for Ruger to come out with a 10mm PC carbine. I just like the versatility of the AR platform when it comes to parts, triggers, etc.

How are 9mm Glock mag AR builds? More reliable than 10mm AR builds I hope.

EDIT: Thank you for the replies.

 

[mdThanatos]

Before you give up on the 10mm, I would call Macon Armory and discuss what you are wanting to see what they say.

As far as the 9mm Glock mag builds, I have one that I put together and love it. I went with PSA for mine and the only issue I had was the two bolts holding the ejector came loose during shooting. I realigned the ejector and put some loctite on them and been good ever since. No jams, or feed issues, ejection has been fine. Works well with the 33rd Glock mags and the ETS mags as well.

 

[rbernie]

I have a PSA 9mm upper and a NFA 9mm upper/lower. I prefer the NFA product because it offers a (kinda hokey, but works) last round BHO that the PSA offering lacks. Both have been highly reliable.

 

[TTv2]

Cool, I'll definitely make the 9mm AR. As for the 10mm, given that it's popularity is gaining and Hi Point just made a 10mm carbine, I think more manufacturers will be following suit. I'll wait and see.

 

[rbernie]

Here’s the NFA 9mm lower on sale:

http://www.primaryarms.com/new-frontier-armory-9mm-stripped-lower-receiver-glock-mags-c9lower-s

 

[Corpral_Agarn]

You need to talk to Rudy at Macon Armory.

He makes 10mm Direct Impingement AR uppers.

He recently completed a 45acp DI Upper for me that has been fantastic.

I cannot speak to the lower. Mine was done by a guy who is out of business now.