7 mm WSM

[kenneth]

I am thinking about building a 7mm WSM to shoot 120gr. bullets. What twist barrel would I need to shoot the 120's at a high velocity? Has anyone had any experience with this setup. Thank fir input.

 

[reed mosser]

I think a 1-9 or 1-10 will stablize the 120's just fine as well as all other 7mm bullets. with 26in barrel and up you should get 3600 to 3700 Fps. Will be excellent for hogs out to 1000 yards. I am swithing from 180's in my 7 wsm's, To the lighter noslers, I don't which one yet. The 120 nor 140's should work great. They kill good, have good b.c and are very fast. Good Luck Reed

 

[dwm]

There is an interesting twist rate tool available at:
http://www.shortmags.org/shortmags/ref_data/TwistRateCalc.asp

Twist rate is a function of bullet length and velocity.

This web site states that if your bullets are going at high velocity the twist rate does not need to be as fast. Bullets stablize at a certain rpm so a slow twist but high velocity will produce the same rpm as high twist rate and low velocity.