Destructor345

Oh I forgot to add, the barrel above is chambered for .308 Win.

My new 20" Lothar-Walther barrel has a .080 gas port, .875 journal, and 15.25" tube (the 15.5" Wilson tube was too long). The gas port is just over 7 1/16" from the muzzle. I would like to use it with a 5.3oz buffer and Sprinco orange spring. Could you please tell me the gas port size it should be?

Hey everyone I have been a machinist, hobby shooter, and hunter since the 80's. I bought my first AR (Dpms LR-308 ap4) back in 2012 shortly after Obama became president. It was a panic-buy I admit and I paid too much for it at the time. I was never happy with the accuracy but I figured it was probably just me using iron sights. Two years ago I finally bought a scope for it (leupold VX-5HD 3-15x44) and it is still terrible. I can get a few rounds in a decent group and then the next one will be like 5 inches off. I feel like something must be moving but I have tried everything I can to insure the optic is secure and also replaced the buffer and spring (5.3 oz and Sprinco orange) which helped the recoil but still, the accuracy is terrible and disappointing. Different ammo has minimal effect. Fast forward to today, I bought a 20" Lothar-Walther barrel and am putting together a new upper with the thought that I will also get a new lower and have two complete rifles. I will then go back to that DPMS and solve whatever it's issue is, whatever it takes. Thanks to this site, I am learning a lot here and have some questions I will ask in the appropriate place.