Thoughts on 150 gr TTSX performance in 7mm WBY MAG

[Dr. Vette]

We've been shooting the 150 TTSX in Dad's 7mm Wby for many years now.
I worked up a load with H-1000 back then, and we still use it. 3050fps, and I could likely push it faster but it has such a great node that I have never changed it. He has taken elk with no issue, and easily out to 500 yards on antelope. I do not believe he has taken anything much further than that.

FYI the 146 Hammer Hunter was specifically developed for the 7mm Weatherby with the 1:10 twist barrel. I pushed Steve for a year to use the nose of the 131 Heavy Hammer and make the heaviest bullet they could for a 1:10 twist. It works well, should you decide to try it.

 

[Spotter's Signature]

But everything I've read about ttsx is try to keep it @ 2000 for reliable expansion. This coming from shared experiences on various threads.

I agree, the faster the better. Notice though, that different weight Barnes projectiles in THE SAME CALIBER need different minimum velocities to open. Some of these differences are large. One of us posted a table here on this forum with minimum velocities required, I added some details about the 150 gr TTSX specifically. This particular one opens at a much lower velocity (1500 fps 1.5x, 1700 fps 2x), which is one of the major reason why I picked it. I'd love them to stay over 2000 fps, but I'd also love them to effectively reach out to 800 yds. Or, 700 yds after all this. Compromises...

 

[Spotter's Signature]

FYI the 146 Hammer Hunter was specifically developed for the 7mm Weatherby with the 1:10 twist barrel. I pushed Steve for a year to use the nose of the 131 Heavy Hammer and make the heaviest bullet they could for a 1:10 twist. It works well, should you decide to try it.

Thanks. At this point, what would be the advantage of this bullet over the 150 TTSX, though? Is it superior enough to work on load development? It's expensive. Its G1 BC is about .42, less aerodynamic than the TTSX. It is also a bit lighter. Unless I could shoot it very fast and its terminal ballistics are significantly better than the TTSX, I'm not sure this is worth it. Would I be able to reach effective 700-800 yds range with it? How fast would I have to push it? Would it shoot well in this rifle at all? Etc., lots of questions. It is an option for the future, though.
I'll keep using the TTSX until I have a real problem with them. Time will tell; wouldn't be the first time. I thought I had perfect loads before

 

[Dr. Vette]

I get 3300fps with the 146 HH in mine using Norma LRP.
Of course, that went away since I developed the load, so I need to choose a different powder next time.

700 yards is 1805 fps estimated, 1056 ft-lbs
800 yards is 1629 fps estimated, 860 ft-lbs

It shoots exceedingly well in my Accumark.
The 131 HH did as well, but you can't use them in the 7mm Weatherby Mark V. Due to the feeding ramp/barrel angle, they get jammed.

 

[Spotter's Signature]

700 yards is 1805 fps estimated, 1056 ft-lbs
800 yards is 1629 fps estimated, 860 ft-lbs

The 150 gr TTSX load gives:
700 yards: 1847 fps, 1136 ft-lbs
800 yds: 1691 fps, 952 ft-lbs

It's splitting hairs, on paper, unless these perform MUCH better on game. At this distance, the theory shows the TTSX to be "better". It would be interesting to see a side-by-side comparison of TSXs with the HHs, terminal performance. I'm very conservative now about putting more mileage on this barrel. I estimate it'll hold precision for another <500 rounds. So, if it's not a new and miraculous projectile with a BC of 1.895, I'll likely not work on a completely new load

 

[Dr. Vette]

The 150 gr TTSX load gives:
700 yards: 1847 fps, 1136 ft-lbs
800 yds: 1691 fps, 952 ft-lbs

Which powder?

 

[Spotter's Signature]

Which powder?

Ramshot Magnum. It's the best overall in my rifle; load details in my original post. I'm at max powder capacity then.