I am using H335 for the contender, and 4895 for the AR. I usnderstand the AR and Mini14 have a slightly looser chamber, so I keep the brass segregated, that is, the contender brass is only for the contender.
I neck size only the contender brass also.
I am using 24 Gr, H335 with a 50 gr bullet, vmax.
No pressure signs. I drop the load and recheck when I change jugs of powder, then work it back up. the company is pretty consistant from batch to batch.
BLC2, 3223, 4895, H322, are al good powders, so is Varget.
Get the powder in 1 lb bottles, and try several loadings of each until you find the exact combo you like: powder type, amount, bullet type, seating depth, brass, etc. Then bulk up on your powder and other components.
Good luck.