Temperature stability Power Pro 2000MR

[sgt_zim]

So I see where PP2000MR has a stability factor of 0.6

That's my powder for both 9.3x62 as well as 404J.

I'm not really even a little concerned about my 404J load - at 2250 fps, even at 100° F, it's still a fairly low pressure load.

I'm not even overly concerned about the 9.3 loads, even though I'm pushing 286 gr A Frames at 2475 and 258 gr Hammers at a little over 2500. Ladder tests for both showed zero signs of pressure at the highest charge weight. I've got the COAL for both those bullets set well past SAAMI spec, with lots of freebore/leade still to spare.

I'm also not worried about modest velocity increases with warm ambient temps. I've done enough LD with heavy 45-70 bullets and all manner of .366 bullets to know any POI changes are meaningless at the sort of distances I'd use either of those.

My question is...should I be more concerned about the 9.3 loads than I am? I had no issues with those A Frame loads last week in northern Limpopo where afternoon temps were pretty consistently in the upper 80s to 90

 

[375 Ruger Fan]

Short answer, no, in my opinion. You live in the Houston area and I would guess your load development work is done during warm to hot days. If you develop a load on a 80F day, then go hunting on a 100F day, the delta is only 20F. Not a big deal. For hunting loads, I just don't think temp stability is a big deal. Shooting at 600-1000 yards, then it matters.

BTW, this temp stability table shows PP 2000MR at 0.99, not 0.6

If it's a concern to you, go with H4350 with a 0.16 temp stability factor. I developed my 338 WM load during warm temps (70-90F) and then shot an elk in Montana at 300 yards on a -10F morning. Load was still accurate with a delta of over 80F!

 

[375 Ruger Fan]

BTW, like your new avatar!

 

[sgt_zim]

Short answer, no, in my opinion. You live in the Houston area and I would guess your load development work is done during warm to hot days. If you develop a load on a 80F day, then go hunting on a 100F day, the delta is only 20F. Not a big deal. For hunting loads, I just don't think temp stability is a big deal. Shooting at 600-1000 yards, then it matters.

BTW, this temp stability table shows PP 2000MR at 0.99, not 0.6

If it's a concern to you, go with H4350 with a 0.16 temp stability factor. I developed my 338 WM load during warm temps (70-90F) and then shot an elk in Montana at 300 yards on a -10F morning. Load was still accurate with a delta of over 80F!

View attachment 630803

I use H4350 for my 280AI loads where temps may be 60 - 80° colder than when I'm doing LD

 

[Inline6]

My question is...should I be more concerned about the 9.3 loads than I am? I had no issues with those A Frame loads last week in northern Limpopo where afternoon temps were pretty consistently in the upper 80s to 90

I think your answered your own question.

My only question to you would be, are you planning on hunting in temps higher than that? If the answer is no, I would not change a thing. If yes, do a little testing in the middle of summer and review the results.

 

[sgt_zim]

Limcroma has some nice dagga boys, but they also operate in Moz and Zim. I think I have a better chance at a scrum cap bull there than one of their Limpopo properties.