What about a 10mm Upper?

[FrankT]

http://www.midwayusa.com/product/76...3-upper-receiver-assembly-10mm-auto-16-barrel

This flattop A3 upper receiver comes complete with charging handle, bolt carrier assembly, A2 front sight, sling swivel, bayonet lug and threaded muzzle with flash suppressor. The 16" button rifled barrel is chambered for 10mm and has a 1 in 16" rate of twist. Ready for installation onto any standard AR-15 lower receiver. Includes one 18 round magazine. Lifetime factory warranty.

Technical Information

• Upper Receiver Type: A3 Flat-Top
• Barrel Length: 16"
• Barrel Contour: Not listed by manufacturer
• Barrel Material: Stainless Steel
• Muzzle Thread Pattern: Not listed by manufacturer
• Chrome Lined: No
• Barrel Finish: Black Matte
• Twist Rate: 1 in 16"
• Chamber: 10mm
• M4 Feed Ramps: No
• Muzzle Device: A2 Flash Suppressor
• Gas System Length: N/A-Blowback
• Gas Block Diameter: N/A
• Handguard: M4 Polymer Handguards
• Sights: A2 Front Sight
• Bolt Carrier Assembly Included: Yes
• Bolt Carrier Type: 10mm Compatible Carrier

 

[Afalex1]

Macon Armory is working on a gas impingement 10mm upper. Last I heard he had one running.

 

[fanninland]

Sounds like it would be a hoot given how much fun my G20 is to shoot. But if you don't reload 10mm the grocery bill is gonna be muy expensivo.

 

[Itsazonik]

I have been looking for one of these for a while. I have my rock island 10mm. I thought a 10mm upper would be great to add to the collection

 

[Delta4-3]

I made a gas operated 10mm AR. When I lived in a neighborhood, a lot of the little neighbor kids used it to kill their first deer. I used grease gun mags in it and it did have some feeding issues. I also tried ppsh-41 mags. Lastly, I tried 20 rd Pmags with a block in the mag with a custom follower and spring. It worked well, but was a pain to make mags for.

If I was doing it over, I would do 10mm magnum. It is longer and should feed better. It also has a little more steam.