but of balance.
If I am understanding correctly, your "Sig Marauder" is the one that appears in your signature:
If this is so, then you need to think of how to move the center of gravity substantially below where it is now.
Try this FIRST:
Use some weights at the END of your bipod. Perhaps a couple of lbs. on each leg will do. This is ONLY a test, so just tape those weights there and tape the bipod fixed, so that the bipod will not move nor allow the rifle to move.
I assume that the point where you balance your knee is the wooden "forearm" of the rifle as pictured.
You can also tape a 3/8" aluminum bar to the BOTTOM of your buttplate jutting STRAIGHT OUT to the rear. 8" protrusion will be enough for this test.
The rifle should now be at least neutral heavy, not top-heavy. And the location of the weights in front of the knee support will make it nose heavy as well. So the "butt-hook" will help your body weight receive that rotational force and stabilize the rifle in its position.
ONCE you find the BALANCE you need, then you can think of trimming the current stock off useless weight being careful to keep the balance of the whole rig as you want it.
You can also play weighing the hollow of your pistol grip to balance the nose heaviness.