I have had great sucsess with Imr 4831 with a 130 grain slug,
in a 22 inch pipe ,In one of them a switch to a mag primer tighten the group up from 3/4 of an inch to 3 touching
I started with this powder and had good results and have never changed
ive used this powder for both 130 and 140 grain pills.
130`s at 3150
140`s at 3000
editnote* i did back off 1 grain of powder for the mag primer as the same load did start to show signs of pressure