I’ve been having issues with an AR build for awhile now. It’s a 16”. I am on my 3rd barrel now and I will absolutely give you I’ve been buying cheap barrels and it seems like this build just happens to have gotten all of the bad ones and I’ve lucked out with all other builds. Or that seems to be the case so far.
First barrel was generic HBAR no name from Brownells for $40. Won’t complain. it shot 3-4MOA. I wanted something slightly nicer. I got a fluted HBAR from Classic (according to them, BCA is their contract manufacturer). I waited a long time to install the barrel and when I finally did it shoots 3-8MOA. They won’t warranty it because I waited over a year to talk to them about it.
Well I ordered a barrel from BCA direct this time. 4-10MOA now. This recent barrel maybe the optic has crapped itself, but the last barrel I tried even with my known good 3-9 scope that shoots sub MOA with the right ammo on my 20” and still horrible accuracy.
Emailed them yesterday and if I don’t hear back I’ll call them by Wednesday. They do have a 1 MOA guarantee on their barrels. And I tried a lot of ammo types and the best I could manage yesterday was a 2.04” center to center 5 shot group at 50yds... it was with IMI M193. Next best was Hornady 55gr match at 2.13” group size. Federal XM855 and PPU M855 were the worst at around 5” groups at 50yds (and tried half a dozen other weights and brands).
I head spaced things and it won’t close on a foster no-go gauge and takes force to close on a go gauge. Which seems suspiciously tight, but the brass has no pressure signs on it. The last barrel swallowed the go that’s fine and wouldn’t take the no go gauge. I tried with my other BCG and same behavior for the gauges. I can drop the bolt (which I don’t like to do) and it’ll go in to battery. It won’t by easing it down or with the gauge set over the extractor and eased in to the chamber. Takes a whack of my 4oz rubber mallet to get the lugs to rotate and I have to very lightly mortar it to get the gauge back out of the chamber. Hand pressure and taps with my palm on the forward assist aren’t enough to get it in to battery.
Both barrels seem a little loose in the upper receiver prior to tightening the barrel nut, but not crazy loose.
I didn’t try my other BCG with this barrel at the range, but the other barrel I did and no effect on groups.
The lower is used with my 20” upper which shoots 2MOA with most cheap ammo and 1 or a little under 1 with match ammo.
So I am pretty much down to a string of bad luck with barrels or some issue with the upper receiver. For the heck of it I ordered a couple more upper receivers since primary had Anderson uppers on sale for stupid cheap yesterday. I’ll try a completely fresh build for the upper if I can get BCA to swap the barrel or if not try the barrels I have on hand in the new uppers.
Any one have any thoughts? Anything I might not be thinking to check? AFAIK I am doing all “best practices” on assembling the upper. Gas key slides over the gas tube without resistance. Gas block is indexed out from the barrel shoulder by a couple sheets of paper. Torqued then loosened and then tightened down the barrel nut 3 times and its set to 42ft-lbs for final torque to index the barrel nut properly for the free float handguard (NSR style eBay special). Gas key properly torqued and staked on the BCG.
First barrel was generic HBAR no name from Brownells for $40. Won’t complain. it shot 3-4MOA. I wanted something slightly nicer. I got a fluted HBAR from Classic (according to them, BCA is their contract manufacturer). I waited a long time to install the barrel and when I finally did it shoots 3-8MOA. They won’t warranty it because I waited over a year to talk to them about it.
Well I ordered a barrel from BCA direct this time. 4-10MOA now. This recent barrel maybe the optic has crapped itself, but the last barrel I tried even with my known good 3-9 scope that shoots sub MOA with the right ammo on my 20” and still horrible accuracy.
Emailed them yesterday and if I don’t hear back I’ll call them by Wednesday. They do have a 1 MOA guarantee on their barrels. And I tried a lot of ammo types and the best I could manage yesterday was a 2.04” center to center 5 shot group at 50yds... it was with IMI M193. Next best was Hornady 55gr match at 2.13” group size. Federal XM855 and PPU M855 were the worst at around 5” groups at 50yds (and tried half a dozen other weights and brands).
I head spaced things and it won’t close on a foster no-go gauge and takes force to close on a go gauge. Which seems suspiciously tight, but the brass has no pressure signs on it. The last barrel swallowed the go that’s fine and wouldn’t take the no go gauge. I tried with my other BCG and same behavior for the gauges. I can drop the bolt (which I don’t like to do) and it’ll go in to battery. It won’t by easing it down or with the gauge set over the extractor and eased in to the chamber. Takes a whack of my 4oz rubber mallet to get the lugs to rotate and I have to very lightly mortar it to get the gauge back out of the chamber. Hand pressure and taps with my palm on the forward assist aren’t enough to get it in to battery.
Both barrels seem a little loose in the upper receiver prior to tightening the barrel nut, but not crazy loose.
I didn’t try my other BCG with this barrel at the range, but the other barrel I did and no effect on groups.
The lower is used with my 20” upper which shoots 2MOA with most cheap ammo and 1 or a little under 1 with match ammo.
So I am pretty much down to a string of bad luck with barrels or some issue with the upper receiver. For the heck of it I ordered a couple more upper receivers since primary had Anderson uppers on sale for stupid cheap yesterday. I’ll try a completely fresh build for the upper if I can get BCA to swap the barrel or if not try the barrels I have on hand in the new uppers.
Any one have any thoughts? Anything I might not be thinking to check? AFAIK I am doing all “best practices” on assembling the upper. Gas key slides over the gas tube without resistance. Gas block is indexed out from the barrel shoulder by a couple sheets of paper. Torqued then loosened and then tightened down the barrel nut 3 times and its set to 42ft-lbs for final torque to index the barrel nut properly for the free float handguard (NSR style eBay special). Gas key properly torqued and staked on the BCG.