308 w/1 in 12 twist and heavies

[30hrrtt]

I have a Savage 99 in 308 with a 1 in 12 twist barrel. I was looking at Mountain Molds to do a custom mold with a looonnng throat, .35. I can get a 210 grain boolit with the boolit fitting in the neck and the cartridge OAL ok for the magazine. On the program it suggests a 1 in 10 twist for this weight.

Anybody shooting a 308 boolit in that weight in a 1 in 12 barrel? How does it stablize?

[lwknight]

I may lose but my bet is that it will not do well.
We have several threads about RPMs and bullet shapes.

[seppos]

Valmet 412 combi with .308 rifle barrel..
20 shots from 75m in -4 fahrenheit temp and from bad rest..
Two shooter error.. sorry..;)
Bullet was NOE 316299 calibrated to .313 and powder was VV:s TinStar (2.2cc LEE dipper)
No gascheck:ies in it..
http://i459.photobucket.com/albums/qq319/seppos_photos/316299.jpg

Greenhill formula is good, but is not like bible everytime..;)

S

[stubshaft]

I used to get 1" - 1 1/2" @ 100 with my Wichita bolt pistol and a 180gr LFN in a 12" twist. That was about the max weight that gun could handle. If I went to 311365 or 311335 (both around 200grs.) the groups would open up at 100 to about 2 1/2" and on the 200yd rams they would show signs of tumbling.

[Larry Gibson]

I've shot numerous 311299 and .311284s at 210 - 220 gr through several 12" twist .308Ws and 30-30s with very good accuracy and complete stability. That weight will do well in the Savage 99 12" twist also if they feed from the magazine, especially in the 1850 -2200 fps range.

Larry Gibson

[Char-Gar]

It is not about bullet weight, but bullet length. Cast bullets of a given weight are shorter than jacketed bullets of the same weight. It is also about center of gravity and bullet design. Also velocity is an important. A barrel of a given twist might stabilized a given bullet at one speed, but not at a slower speed.

This is all to say that charts don't tell the story. Your rifle will. Many folks read too much and shoot too little.

My experience mirrors that of Larry Gibson above. I would venture a guess that it is fact and not opinion.