I have found a 64 gr. charge of IMR4350 under a 168 Gr ballistic Silvertip to be a very accurate (1/2" MOA) in my brothers Browning Abolt with the BOSS System. We tried several combinations and this one shoots the best. Work up to the 64 grain in your gun to check for accuracy & pressure signs. Never chrono'ed the load and it's not listed on Hogdons website, but I used H4350 load comparison and just worked up from there.
I just got mine... From what I know now it kinda depends on your barrel twist length... what you are really going to stabilize as far as weight goes. I unfortunately have a 1:12 twist so lighter bullets are going to probably work better. I am going to start with the 155 palma as its a good round and I know I will be able to push it pretty darn fast. I am going to work up 165 the 168 then 175 and keep going till my barrel wont do it..
I have a friend though that loads a 125 nosler Ballistic tip.. He is pushing it 3800 fps and he shoots deer out to 500 yards.
I am going to be working up some loads soon so I will get back to you!
