Up date on accuracy problem with ar!!! - Printable Version +- 6.5 Grendel Forum (https://65grendel.com) +-- Forum: 6.5 GRENDEL DISCUSSION FORUMS (https://65grendel.com/forumdisplay.php?fid=3) +--- Forum: 6.5 Grendel ARs and Other Semi-Autos (https://65grendel.com/forumdisplay.php?fid=8) +--- Thread: Up date on accuracy problem with ar!!! (/showthread.php?tid=24035)

Up date on accuracy problem with ar!!! - jdd - 12-11-2021 I got the tools in and tore it down. and gave most certainly not a target crown . It was washed out and not well polished. I no longer have access to a lathe so I sent it home with a gunsmith buddy I trust to recut it and polish. Bore scope did not reveal any problems but he was concerned because his range rod seated deeper than normal. I purchased a lapping tool. The Dpms match upper was square and true. I had torque the barrel nut to all I could muster using a cheater bar old school style. I will glue in at roughly 30 lbs as the new logic dictates. I will go a step further though in set up. In the past. I had ar 15 that would shoot bug hole groups if feed one round a time in the chamber. Proving a good barrel and load. When feed from a magazine groups would open greatly. I suspected bullet runout caused by the feeding process. I need to make up some dummies any way to speed up testing at the range. One I had the upper receiver lapped in with out installing the gas block or hand guard. I placed a dummy in a magazine drew a line with a marker to index it , released the bolt and let it slam home. I careful ejected the dummy into my hand . The deep dents in the shoulder were numerous, there was also some additional bullet run out. Out came the dremel for some throating it took quite a bite to eliminate the dent’s to the shoulders. Those dents can not have a postive influence on headspace therefore accuracy. The drag can not have a positive impact on feeding and reliability . Bullet run out alway is detrimental to accuracy. I will report back after testing. I don’t know if the work will over come a possible out of spec bore. I can’t find who the maker was. I don’t see how to post photos . I hope my description is clear and helpful Up date on accuracy problem with ar!!! - Happy2Shoot - 12-11-2021 https://www.65grendel.com/forum/showthread.php?24912-Ar-accuracy-problems Are you working with "PrecisionFirearms"? He made you a killer offer.