WSF VS TEMP?

[Victor_R]

Is WSF temp sensitive? I live in WA where the weather has been around 45-55 degrees. I'll be heading down to TX next week to shoot CB's IDPA challenge where the temp is around 80-90 degrees. With WSF will it raise my PF (which is good) or will it lower it (which is bad). Thanks for any info.

[BMartens]

In my experience, and what I have heard from others, it will lower you PF and it could be quite a bit.

I chroned some 9 major loads recently and a 25 degree increase temperature lowered the PF 7 points. Enough to not make major. Made major at 40 degrees and would not at 65 degrees.

You don't mention your caliber or load so your results may be different. I don't know if it reacts as dramatically in minor loads.

Edited March 29, 2010 by BMartens

[Victor_R]

Sorry. 124gr FMJ Montana Gold WSF 4.7gr OAL(1.134) Crimp(.373) WIN brass and WSP. I chronoed today and I made PF. Here are my results at 10' out of my XDm 9.

1)1010= 125 PF

2)1031= 127 PF

3)1068= 132 PF

4)1017= 126 PF

5)1038= 128 PF

6)1022= 126 PF

7)1068= 132 PF

8)1042= 129 PF

9)1049= 130 PF

10)1047= 129 PF

As you can see I'm right at PF and to hear that hotter weather will decrease my PF is not good. Should I lower my OAL or add .2grs more powder?

[dsmw5142]

You should find an OAL your gun likes and adjust your charge to change your PF. Just my Opinion.

[DWFAN]

5.1gr of WSF and a 124 MG JHP OAL 1.130 gave me 138PF this weekend at ~50deg F through an M&P Pro. I would say 4.9-5.0 would be ok for you depending on the temp's you'll be shooting at.

ETA - the only way to 100% know is to chrono loads at temps you'll shoot them at. Tough to do when you travel to shoot and have a reverse temp powder like WSF.

Edited March 30, 2010 by DWFAN

[open17]

WSF is reverse sensitive.

My Major 9 load:

85 degrees 165.nuthin PF

60 degrees 172 PF

40 degrees 183 PF!

[kaiserb]

Is WSF temp sensitive? I live in WA where the weather has been around 45-55 degrees. I'll be heading down to TX next week to shoot CB's IDPA challenge where the temp is around 80-90 degrees. With WSF will it raise my PF (which is good) or will it lower it (which is bad). Thanks for any info.

It will not be 80-90 degrees in Texas next week... however I think WSF is reverse temp sensitive and a warmer temp will lower your PF. I use about 3.9 Gr. WSF behind a 147 gr molly which makes PF in the TX summer time heat.

[kevinj308]

Could you just leave the ammo in the cab of a vehicle with the heater on? Wrap it in a heating pad maybe. Heat up a loaded mag to the ambient temp in question and shoot it over a chrono. I live in the sunny southwest so I've left my ammo in the icechest to see how it was gonna be somewhere colder.

Just a thought

Good luck

Kevin

[Victor_R]

Thanks to all for the advice. Much appreciated. I'm going to run 4.9grs of WSF and see where I'm at. Kevinj308 I'm going to give that a try and also just to be safe I'm going to leave my ammo in a ice chest at the match. Kaiserb, that temp was what my sister told me it was in Kingsville so that's what I went off of. I'll update on the chrono results when I get back on April 13th. I'll ask if they can chrono the 4.7gr loads just to see where I'm at. I wont be using that load for the match though I wish I could because I'm so use to it. Again thanks for the help.

[Sarge]

Sorry. 124gr FMJ Montana Gold WSF 4.7gr OAL(1.134) Crimp(.373) WIN brass and WSP. I chronoed today and I made PF. Here are my results at 10' out of my XDm 9.

1)1010= 125 PF

2)1031= 127 PF

3)1068= 132 PF

4)1017= 126 PF

5)1038= 128 PF

6)1022= 126 PF

7)1068= 132 PF

8)1042= 129 PF

9)1049= 130 PF

10)1047= 129 PF

As you can see I'm right at PF and to hear that hotter weather will decrease my PF is not good. Should I lower my OAL or add .2grs more powder?

You don't want to run that close to 125 anyway. Shoot for 130+ no matter what the weather.

[BMartens]

Thanks to all for the advice. Much appreciated. I'm going to run 4.9grs of WSF and see where I'm at. Kevinj308 I'm going to give that a try and also just to be safe I'm going to leave my ammo in a ice chest at the match. Kaiserb, that temp was what my sister told me it was in Kingsville so that's what I went off of. I'll update on the chrono results when I get back on April 13th. I'll ask if they can chrono the 4.7gr loads just to see where I'm at. I wont be using that load for the match though I wish I could because I'm so use to it. Again thanks for the help.

Couple of problems if there is a chrono stage [level II+]. You will normally bag 8 rounds for the chrono right after the shooters meeting so whatever the ambient temperature is when you get to the chrono stage is what you will get. Most of the time the rounds are in the shade but they will warm to ambient temperature by the time you get there. And no, they won't keep them in a cooler for you. Once you turn your chrono rounds over to match officials it is out of your control.

Also, there is no courtesy chrono for "other" ammo. If you run it over the chrono and it doesn't make PF then you shoot for fun. If it's a match then the chrono stage is official and whatever you chrono, the lowest result, will be your official numbers.

For your own testing you can warm up your ammo before you chrono in cooler weather and get reasonable good results.

I agree with Sarge, 129 PF is pretty short on cushion for WSF when going to a warmer climate.

[BMartens]

WSF is reverse sensitive.

My Major 9 load:

85 degrees 165.nuthin PF

60 degrees 172 PF

40 degrees 183 PF!

What is your 9 major load? I'm seeing pretty similar results.

I'm shooting 6.9 to 7.1 grains @ 1.150 OAL with MG 124 JHP and WSR.

I shot a 6.9 batch at 40 degrees and got a 169PF and at 62 degrees it was 162PF.

If I stick with WSF I might have to get a weather report before reloading match ammo.

[open17]

WSF is reverse sensitive.

My Major 9 load:

85 degrees 165.nuthin PF

60 degrees 172 PF

40 degrees 183 PF!

What is your 9 major load?

7.3 WSF, 1.140 OAL, Precision Delta 124, WSPM. Out of a Glock 17, KKM barrel, 3 blow holes.

I'm going to go to Silhouette, Auto-Comp, Maybe HS-6. Might even go back to 3N37--7.5

of 3N37 was my backup load when I was shooting HS-7. I've got a pile of SP-2, but I really

hate loading it. NO MORE WSF! The 165.nuthin was at Area 2, and that took 6 rounds

to get.

[BMartens]

WSF is reverse sensitive.

My Major 9 load:

85 degrees 165.nuthin PF

60 degrees 172 PF

40 degrees 183 PF!

What is your 9 major load?

The 165.nuthin was at Area 2, and that took 6 rounds to get.

Ouch 95 degrees and you might have trouble making minor.

I have a good working load with Silhouette [8.0] and HS-6 [8.1] and neither shows much temperature variation at all. I like the way WSF shoots but it was 95+ at A3 in 2008 and I don't know if I can make major when it is that hot.

[Victor_R]

I bumped my load to 4.8gr of WSF OAL(1.134) Crimp .372 with WIN brass and WSP. Here are my results.

Temp 50 degress

1)1092=135

2)1093=135

3)1093=135

4)1097=136

5)1075=133

6)1091=135

7)1078=133

8)1099=136

9)1072=132

10)1069=132

The first 5 results were with a cold mag and the last 5 were with a hot mag. I loaded up a mag and let it sit on my heater in my truck for about 10 minutes then pulled it out and ran it through the chrono. I called Hodgdon and asked them about the temp change in WSF and they said I wouldn't see any change from 50 degree temp to a 80 degree. temp.