Weather Temp. and Chrono results

[jdlincoln]

Hi folks,

I'm new to handloading. We shoot primarily IDPA and some USPSA. Since it's a long winter without competition, I'm looking to spend some weekend time loading both 9mm and 45 for next years competitions, but I need to be sure we can make PF before I load 5K rounds. Pro Chrono coming soon.

My question is: If I chrono my handloads this winter in temps raging from 20 to 30 degrees F, what kind of increase/decrease in fps/PF can I expect when shooting matches next spring/summer in 60 to 90 F weather?

I'm using Power Pistol for 9mm and Win 231 for 45acp.

Thanks for your input,

John

[Sarge]

If you do enough research on here you will find your answers. Some powders are temp sensitive meaning they weaken in cold weather and get hotter in hot weather. Other powders are the exact opposite and get hotter in cold weather, weaker in hot weather. Some powders are stable across the board. I believe 231 is listed as reverse temp sensitive meaning it is hotter in cold weather and will be weaker once summer hits. Don't know about PP

You should be able to search the 9mm and .45 reloading threads and find what you need to know.

[jcc7x7]

I chrono on those really nice days in the winter.

I usually go to 170-171 power factor for major and 130 -131 for minor and if I chrono on a 40-45 degree day they seem to hold up just fine during the summer unless you travel to the southwest..

BUT

once you have the chrono about a month before any major match I re-test my loads. and if necessary readjust to get the PF I'm looking for.

W231, WST and Clays at 170 PF have made every chrono i've run across with a 45acp.

Power Pistol is a power that seems to work best at the high end of the loading spectrum. You might want to try 231 in the 9 also, tiegroup with jacketed or plated. WSF, AA2, AA5, are worth a try.

Imr SR 7625 is a very very stable powder and works great in the 9mm if you can find it.

Good fortune

jcc7x7

[jdlincoln]

Thanks Sarge and jcc7x7 for the input. As I said, I'm new at this handloading game, and need all the help I can find. Unfortunately, up here in the sticks, I don't have anyone else that shoots pistol competitions and handloads to mentor me. Our nearest USPSA match is 40 miles and nearest IDPA 130 miles.

So...I've sorta just jumped in with both feet after researching on the net and talking to a few people at matches. I'm loading with a L&L AP, and so far everything is going well other than a few operator/newbie issues. The GOOD part is that the 9mm I have been loading with 3.9-4.1 gr PP @ 1.133 OAL,147gr Berrys plated, has been working well. I've shot 3 local matches since beginning in mid October, and the load feels a lot like the unobtainable Federal 147 gr FMJ's that I was trying to copy. All rounds have cycled and gone bang also! Accuracy with Berry's plated seems at least as good as the Federals, but I haven't really shot any off a rest yet. I have various different bullet mfg.s to try this winter for both calibers so now that the chrono is here, it should be interesting and fun.

We're shooting XDM 5.25's in 9 and an XD 4" in 45. Sometimes the wife shoots her 226 Sig.

Thanks for the help, any more is always appreciated!

John