Home Forums Reloading Big Game Rifles Help “balancing” when changing primers

The 2024 Hodgdon’s manual has an article on primers. They state “Generally speaking, you can expect a 1000 psi increase in pressure for every 11 fps increase in velocity,…”

I believe MD has posted to that effect too.

Yep he did. Just for chits and giggles I ran that 140AB load through predictive software so take it with a grain of salt ~75K psi.

Somebody needs to call up Hornandy and tell them there factory 139 2950fps ammo is over pressure

Are they doing that with Reloder 15?

Your gonna havevto ask them that.
Does every 24" barrel shoot the same speed at the same charge?

It looks like your current load is at least a couple of grains over the book max in both the Nosler and Alliant manuals. The advice provided above to start low and work up is a good idea.

It gets hot in Africa and Reloder 15 is somewhat temperature sensitive, although not as much as some other popular powders. The suggestion to try Big Game is a good one as it works great in the 7mm08 and is relatively temperature insensitive.

Alliant doesn't even list 15 with 140's that i could find.
Manuals are not the absolute end all be all there a guide and I bet if you called them they would tell you that.
I've seen barrels shoot 50fps difference with the exact same load in equal length same powder lot, primer, bullet and cases. Any body who has shot enough will tell you no 2 barrels are the same and different lots of powder can be to
If you look in the Nosler manuel a 338 WM they list RL19 as the fast and most accurate at max 76.0 RL19 at 3,000 with a 210 NP, mine wouldn't even go over 2800 fps at 77.0 no matter how much 19 I put to it.
It shoots IMR 4350 with the 210's at 2950fps with 72.5 but the manual says max is 2902 at 73.0.
Manuel's are a guide no more no less

Here is a more experienced handloader putting up his hand and saying "Whoa!"

I had a 7mm-08 load that I was working up last year. I was using Staball 6.5, and long before I got to the MAX load in the data, I got pierced primer. OK. I backed off a bit, got good results, declared success and went to load up a batch for deer hunting. I didn't realize that I'd gotten to the bottom of the box of brass, and I had to switch from FC to WIN. Luckily, I measured the new brass. There was a good 3 grains difference in what it would hold.

Back to the range. Wash, rinse, repeat.

Look, I've changed a component here and there over the years and not been bit, but it's always been on my downloaded hunting rounds that are down around the MIN velocities to begin with. Usually, there's no big deal, and that's a benefit of poopy loads. However, there have been times when I get MUCH better velocities (still under MAX), but it reminds me that this stuff can go looking for the asymptote in a hurry when you least expect it.