That is a can of worms. I prefer the bipod as it gives me more consistency. I have found the buttpack to shift and collapse at the most inoportune times.
I heard of pre-packing with non-shifting stuff but now you have a butt pack that is not good for anything else. The ruck can also get yo up high enough to become unstable. If I need to be up that high I would prefer a tripod of sticks or even a camera tripod.
My two cents on the subject.
Waiting for the Mairne contingent to voice their opinion.
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Hold Hard guys
Rick B.
Knowledge is knowing a tomato is a fruit.
Wisdom is knowing it is great on a hamburger but not so great sticking one up your ass.
Author - Richard.
Experience is what you get right after you need it.
Author unknown.