Struggling W/ Armalite AR-10

[kmc0929]

Having issues with an older AR-10(T). Gun started out as a 24" SS Target Barrel W/Free Float Tubular Handguard. I had a local smith cut the barrel down to 16" and install an Armalite forend (as pictured). I assume the twist rate (unknown) wasn't accommodating to the shorter barrel, as it will not seem to group anything within 6".

With that said, does anyone know of a barrel manufacture that will make a heavy 16" barrel for this pattern rifle and install it? Can I have a new barrel installed WITHOUT having to replace the bolt? Parts for these guns seem to be hard to find.

 

[db2000]

Twist rate won’t be affected by the chopped barrel. Possibly the crown was damaged with the chop. New shorter barrel may not like same ammo as before. I’d have the smith shoot it and see what results he gets. Bring 3 different types match ammo with you. 168 SMK, 175 SMK, etc. Shoot without the can to eliminate that variable.

 

[sinister]

I have an AR-10T that started like yours (24-inch Lothar-Walther tube I had cut down to 22 inches, then to 20. Removed the Armalite tube and replaced it with an SWS and now a Geissele). Precision tested the last time it left the shop it put 10 rounds of meh GI white box 7.62 168s into 2.98 inches at 300 Meters from a mechanical rest.

My guess is you have a crown that may need to be re-done or check the barrel nut torque.

Find a better gunsmith. A bolt should generally be good for at least three barrels. Once it's done you don't have to use an Armalite (I've used LMTs and JPs, but most generic 308 bolts will work if it passes headspace).

 

[Cascade Hemi]

Check for clearance between the gas block and handguard.

 

[Hecouldgoalltheway]

6" tells me that you have a problem with either the crown (as mentioned), or the assembly post barrel chop (as mentioned). Did you ever shoot it in its original length? Was it accurate before taking it to the gunsmith? Barrels don't become less accurate when shortened, in fact, they should become more accurate as long as it is done correctly. There are a handful of things that could cause this, but I would start by disassembling the upper receiver, (handguard, gas system, barrel nut, barrel, and looking for a problem. I think you'll find your issue.