[AlbertaAl]

Most sporter rifle stocks don't have a FLAT forestock bottom and are instead rounded making them easily roll in a sandbag or pedestal style front system.
I use a "benchrest" (LOW model) HARRIS bi-pod which is attached to the front swivel stud and keeps the rifle square on target.

I've fitted almost all my stocks with under forestock aluminum rails. These have been installed professionally by REMPLE.
In conjunction with the rails I purchased the REMPLE aluminum bi-pod.
Again, the bi-pod keeps the rifle square to target.

My postioning on the bench includes positioning the rifle as low as possible to the table top. I NEVER touch the forestock. The rear stock is in a quality firm sandbag, I use a hard hold by leaning into the rifle stock and securing it with my my spread out thumb and forefinger with the loose hand. The palm of my shooting hand is "very lightly" wrapped around the pistol grip. I found a tight grip causes poor groups.

I always shoot one or two fowlers at the start since I always go with a freshly cleaned barrel. During the shooting process I avoid over-heating the barrel.
My ammunition is kept away from the direct sun. I seldom go to the range with just one rifle...rotating rifles keeps me from being bored and gives rifles ample time to stay cool.

Vertical groups are my biggest dilemna... lots of variables to choose from and can be frustrating but that's just another reason to go back to the range with new reloads and do more testing !