I was at the range today trying out my new green laminate thumbhole stock. I was shooting at 100 yards. and was not able to keep three bullets inside of a 2 to 3 inch group. The gun is a .308 Survivor with a bull barrel. Here's a breakdown of what I have done so far.
1) Trigger job by a gunsmith. It breaks clean at 2.5 pounds with no creep.
2) Changed the original Survivor stock to a thumbhole laminate.
3) Original forearm in place, but I was shooting it with it removed. Put it back on, and saw no difference.
4) Made sure that the barrel latch was dry, and that I closed the barrel firmly.
5) Front sandbag was placed at the hinge-point of the barrel and receiver.
6) 3x9 Nikon scope is mounted tight, as is the scope mount to the barrel.
7) I use once-fired Federal premium brass (a friend is a sniper on the local PD SWAT team and gives me all that I want). Each casing is full-length resized, trimmed to proper length, and each powder charged is weighed on my digital scale.
I'm using Varget, 4895, and Accurate 2520 for powder, and Hornady and Remington bullets of 150 and 165 grains. No matter the combination of powder and bullets, groups still avarage around 2-3 inches at 100yds.
9) Total rounds out of this gun is about 100 to 150.
Am I asking too much of this gun to shoot smaller groups? Can anyone give me some more tips?