View Full Version : Chopping an Upper Down
About a year ago we received eight AR Upper Receivers. Because of a blunder we received 16" Uppers and not the 10.5" Uppers. They have been sitting in the Box ever since.
I am asking is it feasible to have these cut down to 10.5". I already have the Legal aspects covered. All of our Lowers are registered as SBR"S.
1. Will these perform as well as a 10.5" out of the Factory, after being cut?
2. Doe's anyone know a Company/Gunsmith who can do this?
3. We would also need the Barrel threaded to attach the original Bird Cage Flash Suppressor.
The Reaper
02-04-2009, 08:22
About a year ago we received eight AR Upper Receivers. Because of a blunder we received 16" Uppers and not the 10.5" Uppers. They have been sitting in the Box ever since.
I am asking is it feasible to have these cut down to 10.5". I already have the Legal aspects covered. All of our Lowers are registered as SBR"S.
1. Will these perform as well as a 10.5" out of the Factory, after being cut?
2. Doe's anyone know a Company/Gunsmith who can do this?
3. We would also need the Barrel threaded to attach the original Bird Cage Flash Suppressor.
Yes and no.
You cannot just cut the barrels to 10.5", rethread to 1/2-28, and expect the guns to run properly. The pressure, timing, dwell time, impulse, etc. are all different.
A good gunsmith could cut the barrels, rethread them, change the gas port size, check the extraction, add a heavier buffer, etc.
It is possible that they will run without any tweaking, but I would say that it is unlikely to be reliable.
Given the machining and 'smithing costs, it might be more economical to order 10.5" uppers or barrels and swap them out, and sell the 16"ers.
Your call though.
TR
As hard as it is to find good 16" barrels right now, I'll second what TR said. It seems that finding 10.5" isn't as hard since not everyone wants to go to the SBR route. With the Gun Ban buying frenzy, I'd bet those 16" barrels would be gone in a week.
Yes and no.
You cannot just cut the barrels to 10.5", re-thread to 1/2-28, and expect the guns to run properly. The pressure, timing, dwell time, impulse, etc. are all different.
A good gunsmith could cut the barrels, re-thread them, change the gas port size, check the extraction, add a heavier buffer, etc.
It is possible that they will run without any tweaking, but I would say that it is unlikely to be reliable.
Given the machining and 'smithing costs, it might be more economical to order 10.5" uppers or barrels and swap them out, and sell the 16"barrels.
Your call though.
TR
I'll echo TR, and add that the machine work and testing needed on the port would be more expensive than buying new barrels and having you armorer re-barrel the uppers you have..
There is also the barrel contour,, putting it on a milling machine to get the correct 10.5" contour,, if needed for the attachment of toys,, is not cheep nor advised..
Get you scrounge(S4) to trade them to someone with the 10.5" uppers!! :eek::rolleyes::cool:;)
My $00.0002
Thats the info I was looking for, thanks All.
We did order 10.5" to replace the 16". But as a LE Agency I don't think we can put the 16" uppers on Guns America to sell:D
The Reaper
02-04-2009, 09:53
Thats the info I was looking for, thanks All.
We did order 10.5" to replace the 16". But as a LE Agency I don't think we can put the 16" uppers on Guns America to sell:D
Roger that. You should probably turn them in to your SF buddies for destructive testing over an extended period.:D
Seriously, you may be able to swap them to another entity or turn them in to your DRMO equivalent.
TR
We did something simlar as a test and it did not work well. Weapon had to be run with a surpressor for it even to function correctly(more backpressure). If you just use a crowning tool and cut them itll work. But I wouldn't trust my life to it thats for sure.