Probably this has been covered but I can't find a search function.
I have shot 139 gr interlocks and 74 gr H4831 in my 7MM WBY for deer for to many years to admit to.

I am going to try 140 gr tripple shocks,and was wondering if any of the newer powders would provide a real advantage.I like the H4831 but I don't want to be missing anything either.24" with a 1 in 12 twist.

Nice site

thanks

IMR 7828 will give you higher velocities -- in fact, it seems to yield highest velocities in most of the Weatherby calibers with most bullet weights.

Several years ago IMR issued a loading manual with a special page devoted to Weatherby calibers and IMR 7828 powder. See if you can still get a copy of it.

Accuracy may or may not be best with 7828 -- you have to try it in your rifle with the bullets you wish to use.

While I agree with Loyd that IMR 7828 is a great powder for the 7mm Wby Mag, I don't think it offers any advantage with the 140 grain bullets.

IMR 7828 is the powder of choice in my 7mm Wby Mag for 160 grain bullets, period! It provides high velocity and great accuracy.

However, when messing around with 140 grain bullets, in my gun at least, H 4831 and RL 22 were better choices.

With your 1 in 12 twist rate you will probably be better off with the bullet weight range you are currently shooting. But, it you decide to try heavier bullets then IMR 7828 is a great choice.

R F

will a 1-12" twist stabilize the long 140 gr. Triple Shocks that well?? Them X's in 140 gr. are about as long as most 160 gr. bullets, just a thought.

I finally went out and shot these things.I an quite impressed.They are the same length as a 160 partition which my gun doesn't particularly like.But over 75 gr of h4831 they shot Weatherby's guarenteed 1 1/2 " group at 300 yrds.
I also changed from 154 interlocks to 154 interbonds and got the best results with IMR7828.My question now is -What can I expect from the IMR7828 in the cold?I work up my loads at about 40deg and hunt between 60 and -20 deg

Cmanley: Just got back from the range and head great luck with 140 TSXs & 74gr of H-4831, CCI-250 primers and Norma or Weatherby brass. I did also try it with Fed 215 primers, but with the 250 primers, they printed right over the 139gr Weatherby factory loads. No pressure signs. jorge