Bench techniques for AR's

[Dr. Lee]

I have a PF built 16" Krieger barreled upper that I am having trouble getting consistent groups with. I managed to get one 3/4" group, but the others are all about an 1.5"-2". This is with PF assembled ammo with 123gr Lapua Scenars and Lapua brass. Thinking about the variables, such as scope and mount, which I may switch out, I had to look at my bench setup. I made a 3" wide front bag runner to fit in a standard 3" wide benchrest bag and made a 1" diameter Delrin bag runner for the rear bag. It all feels solid and slides very smooth on the bags. It does however like to bounce some on the front. My rest is a Caldwell Fire Control rest with the joystick. After every shot the reticle does not come back to the center of the target. I have to readjust the rest after each shot. I really don't know I managed to shoot a group with 4 shots touching and one outside making the 3/4" group. How are you guys shooting your AR off a bench to test ammo and get consistent groups ?

Thanks,
Dr.[ATTACH=CONFIG]18531[/ATTACH]