CRJ1960,
Have had a few 1-10 twist .250s, including one of the tang-safety Ruger 77s Ultra Lights with the skinny 20-inch barrel. In that particular rifle 100-grain bullets shot best with 35.0 grains of Accurate 2495, which is their version of a 4895. Never got that rifle to shoot very well with 115-120 grain bullets, despite the twist--perhaps because of the slim barrel. Had a Savage 99A, the later tang-safety model with a 20-inch 1-10 twist barrel, that shot 100-grain Speer Hot-Cors well with 33.0 grains of IMR4895.
I also had one of the 1-14 twist Winchester Model 70 Lightweight Carbines that 260Rem mentions that shot just about any 100-grain spitzer well with either 41.0 grains of H4350 or 36.0 grains of Big Game--the bullets including the Hornady Interlock Spire Point, Nosler Partition and Speer Hot-Cor. (The Interlock, an excellent bullet, is now discontinued.)
Other 1-10 .250s did shoot OK with 115-120 grain bullets. A Remington 700 Classic did well with 115-grain Nosler Partitions and 42.0 H4831, and a custom .250 on a Remington 700 action with a 1-10 Hart barrel liked 43.0 H4831SC with the 115 Partition--but it shot best with lighter bullets from 75-100 grains with Reloder 15.
My last .250 was a Savage Axis, with a Shaw pre-chambered and threaded 1-10 twist, 22" barrel I installed myself, and it might have been the most all-around accurate .250 I've ever owned. Here are its best loads, all of which grouped three shots at 100 yards into an inch or less:
85-grain Ballistic Tip/36.5 grains CFE223/3098 fps
100 Speer Hot-Cor/ 35.0 IMR4895/3038 fps
100 Barnes TTSX/ 35.0 Reloder 15/2963 fps
117 Sierra GameKing/37.0 IMR4451/2745 fps
IMR4451 is very close to H4350 in burn-rate, how close depending on the specific lot ow powder. With my present lots 4451 requires perhaps a half-grain more powder to match velocities with H4350 in cases that size.
