I used to load my bipod and experienced the same thing you did at first. However, the biggest problem with loading the bipod is that it is not consistent. It's impossible to apply the same amount of pressure each time you load it. Also as you experienced, you may not always have to ability to load your bipod. When shooting from the bench using a bipod and rear bag it is best to get squared up directly behind the rifle to best manage recoil. Should be similar to a prone position, but more upright. The cut out benches are designed for BR shooters using an adjustable front rest and rear support that guides the rifle through it's recoil path. Shooting from a bag and bipod are much different and much more shooter reliant.

The below group was shot yesterday during load dev from prone on a bipod and rear bag with my 6.5x47. I would bet with a few tweeks that 338 could be tightened up quite a bit!

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