I have a couple of original Orberndorf Mauser rifles am trying to load for. So far, I have settled on 100 gr. Nosler Partitions. After trying several loadings, I have surmised that at slower speeds these rifles will produce 0.5"groups. As I try to increase the speed, the groups open up. Question, were these rifles supplied with 1:12 twist rates therefore wont stabilize bullets over 90 gr.?? I am not willing to mess with the wood on these therefore bedding and barrel channel work is out. The action screws are torqued properly and the old trick of fore end tip pressure hasnt worked. Any suggestions?

I have a Rem. 700 Mountain rifle in 7X57. It too would only group at very low velocities. Then for some strange reason I went against all conventional wisdom that was given here at the AR forum and used a slow powder for that particular cartridge (RL-19). Although my velocities are not as high as I would like (2650 fps w/150s), they are acceptable and better than the previous slow accurate loads and the gun groups pretty good. Most of the time at 1 MOA at 200 yards, not always but most of the time.

I also have a 250 Savage in a new Savage M-16. It is the least picky rifle I have ever owned. Doesn't really care what powder I use - so far. Almost always under .75 MOA at 200 yards (and several much less than that) EXCEPT when the barrel gets 30 shots or so fired in it. Then it is time for a cleaning. That too may change after more usage.

i have a winchester light weight carbine in 250 and it is borderline for stablizing 100s. It will do ok with some 100s but you have to really kick up the velocity to get them to stablilize. it has a 1-14 twist. My ruger internations is a faster twist gun and will even shoot 120s well. If you have a slow twist gun more speed will usually help you not hurt you.

No problems with 100s and heavier in 1:10 twist barrels. It is the old 1:14 that gets marginal past about 90 grains, depending on bullet design. My 1940s Savage Model 99 with the 1:14 does much better with 87-grain slugs than it does with 100s.

Thanks all.