Re: 155's for my new Bartlein 1/13 barrel
My palma gun has a 1-12. I feel the 1-13 is on the edge with trying to shoot 175's if I wanted that option. I don't like running the stuff on the edge so I put a 1-12 on my gun.
My tactical gun, and a couple of other rifles are all 1-11.25. My rebuilt 1903 Springfield as a Model 1941 USMC sniper rifle is a 1-11 twist. I shoot primarily all 155 Lapua's thru them and all of the guns just pound them. 175's are my back up bullets for loading and for factory ammo like Black Hills etc....
My one gun for testing that I'm doing right now is chambered in 7.5x58mm (8 mauser necked down to .30cal.) is a 1-11.25 twist as well. I let our 14 year old use it in a mid range F-Class match two weeks ago and I coached him. The load was 49.0 of Varget with the 155 Lapua's. Velocity on the brand new barrel (less than 40 rounds) was 2940fps. Now that it has about 150 rounds thru it I'm going to rechronograph it. Any ways he shot the spindle out of the marking disc at 500 yards twice in a row. He put 4 rounds thru the same hole at 500 yards. He shot really good and had a good time for his first match and wants to do it some more. He just shot off a bipod and rear bag.
When I tested the first rounds/group thru that gun at a 114 yards the very first group measured a .137.
I'm rebuilding a Remington Model 30 Express right now. It's still .30-06 but that barrel as well is a 1-11.25. First loads I'll run thru it will be the 155 Lapua's for testing purposes. For hunting mostly going to shoot 165gr. Ballistic tips or 165 Sierra Gamekings.
Later, Frank
Bartlein Barrels