Out of a custom barrel, I shoot 180grs of T7 using a LMRP. The barrel is swabbed between each shot with Butch's BP Bore Shine and a single patch. No crud ring builds up as long as its swabbed between shots and you can literally shoot it all day like that with no loss of accuracy. It takes 5 patches to clean the bore to put the rifle away.

NOTE: The charge is shot in a custom rifle barrel. Do not attempt a charge that heavy with a production barrel or, a barrel not designed for that heavy a charge.