Pathfinder2041 Posted July 4, 2016 Report Share Posted July 4, 2016 Just Recieved an upper that I bought with a Blastic Advantage barrel in a Aero precision Upper receiver. Upper has a Aero melonited bolt carrier group. Current round count is 125 rounds and barrel was broken in for first 30-40 round by shooting and cleaning. Lower has Girsiele trigger. rifle shoots 3.5" groups with Black Hills Gold 175 grain tipped match kings at 100 yards. 3.25" groups with Hornady precision hunter 178 grain ELX rounds. 2.5" groups with black hills gold 168 grain AMAX. FGMM 168 grain SMK was nettin a 2" group. scope was able to assist with a clover leaf sub MOA group on another 7.62 upper receiver. my first thing to do is send this back foe inspection and repair/replacement. My question is what could have caused this? My first guess is barrel nut not torqued or barrel to upper mating surface on the upper is out do spec or not square. Any ideas on what could cause this? Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 4, 2016 Report Share Posted July 4, 2016 How are you testing this rifle , off sand bags front & back of rifle ? Are you sure the Scope is not moving in the mount or rings ? Some Barrels shoot better then others , but should shoot better than what you are getting if on stable rest. Whats the Twist rate ? Could also be a Chamber issue. Is there a Muzzle Device on the Barrel ? How is the fit of this Upper in the Lower Receiver ? Quote Link to comment Share on other sites More sharing options...
Pathfinder2041 Posted July 4, 2016 Author Report Share Posted July 4, 2016 Barrel is a 1/10 twist stainless steel. The barrel has a proprietary muzzle break that is very effective. I had the front of the rifle supported with a atlas bipod, the rear was in a Caldwell bag. I torqued the scope in the mount this morning with a fat wrench set on 35 ft pounds (may be inch pounds, will clarify later if needed). The fit between upper and lower receiver is pretty tight. I am willing to try a second scope to remove that variable, but the scope and mount was used to shoot a sub MOA group on a PWS Mk216 upper & FGMM. Quote Link to comment Share on other sites More sharing options...
washguy Posted July 4, 2016 Report Share Posted July 4, 2016 Path Sometimes you just get a barrel thats not up to snuff....you have done your best I think.... Wash Quote Link to comment Share on other sites More sharing options...
shepp Posted July 4, 2016 Report Share Posted July 4, 2016 Maybe a Stupid question but have you tried other ammo with it? Quote Link to comment Share on other sites More sharing options...
Fletch Posted July 4, 2016 Report Share Posted July 4, 2016 I had a similar issue a while back (best was 1.5" with Fed 168 GMM, everything else was 2"-ish best...I ruled out everything except the barrel (which like your Ballistic Advantage, came with a sub-MOA guarantee)...I ended up sending the barrel back to the manufacturer and sure enough the best they were able to get was 1.5" also, they replaced the barrel and the new one shoots consistent 3/4" groups. My guess is that the barrel is most likely your issue. BA has a lot of info for troubleshooting and contacting them for accuracy issues so they should take care of you without a hassle, I would definitely give them a call and go from there. Did you build this upper yourself or did you purchase it assembled? Quote Link to comment Share on other sites More sharing options...
unforgiven Posted July 4, 2016 Report Share Posted July 4, 2016 Last time there was an issue with inconsistent shot groups it was loose barrel nut.Have you checked that ? Quote Link to comment Share on other sites More sharing options...
Pathfinder2041 Posted July 4, 2016 Author Report Share Posted July 4, 2016 I think it's the barrel nut too! I want to check but afraid I'll eat the cost of the upper if I disassemble it to check. Quote Link to comment Share on other sites More sharing options...
unforgiven Posted July 4, 2016 Report Share Posted July 4, 2016 You won't damage anything with the right tools. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 4, 2016 Report Share Posted July 4, 2016 (edited) Its easy to tell if the Barrel is loose with out disassembly , Remove the Upper from the Lower Receiver & remove BCG & just grab the bbl. in one hand & the other on the the Upper Receive & see if you can perceive any play between the two . Or you can remove the Hand Guard , sometimes removing it may require special tools , as has been mentioned . Depends on whats one there . I would also try shooting with the Hand Guard supported on a good rest ,with out using the Bipod. You want to eliminate the easy stuff before condemning the Barrel , you just never know , but the Barrel may be suspect . I would try M 80 Ball also , some barrels/chambers may like a certain ammo . The only 1-10 Barrel I have seen that didn't like 308 ,168gr. ammo , the Barrel was loose . Edited July 4, 2016 by survivalshop Quote Link to comment Share on other sites More sharing options...
Pathfinder2041 Posted July 4, 2016 Author Report Share Posted July 4, 2016 Just cleaned the upper and with the BCG out, tried the wiggle test. I could not feel any play between the barrel and receiver. I'm going to reload some 178 grain AMAX bullets with varge to powder and try again with a different scope I own that is working fine on a different rifle. If the results are similar, it's going back to the shop for a repair/replace. thanks for all of the help and suggestions! Quote Link to comment Share on other sites More sharing options...
Pathfinder2041 Posted July 6, 2016 Author Report Share Posted July 6, 2016 (edited) the muzzle crown has a manufacturing defect in it. Shot FGMM 168 and 175 grain loads with the smallest group right at two inches. Prior to cleaning, when viewing the crown there is a bright (non-powderfowled bump) in the crown in the 3 o'clock area of the crown. Contacted the builder and will be returning for replacement. Edited July 6, 2016 by Pathfinder2041 additional infomation Quote Link to comment Share on other sites More sharing options...
survivalshop Posted July 6, 2016 Report Share Posted July 6, 2016 Great to hear you found the issue & they are taking care of you . Quote Link to comment Share on other sites More sharing options...
washguy Posted July 10, 2016 Report Share Posted July 10, 2016 Great Work! Wash Quote Link to comment Share on other sites More sharing options...
unforgiven Posted July 11, 2016 Report Share Posted July 11, 2016 Shows how critical the muzzle crown can be and the effects of damage. Quote Link to comment Share on other sites More sharing options...
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