Temperature makes a difference!

[Texas10mm]

We all know it does. I had it proven to me over the past few months.

Last year in October I had tried some light .45 ACP loads. I loved the way they shot and the soft recoil. Come November when it was 40° colder those same loads wouldn't cycle my 1911 I use in matches.

Buddy told me I had loaded them too light.

I gave him a box of 100 rounds. 50 of each load. Told him to hold on to them.

Today we were at the range and it was a nice pleasant 72° out. I asked him for that box of ammo. Both loads cycled perfectly. He couldn't believe that pistol loads could be affected that much by temperature.

The powders in the loads were W231 and Vectan A1.

Now that we're in the warm part of the year here in N. Texas I'll be loading up 500 of each for shooting.

 

[Blue68f100]

Use a reverse temp sensitive and it will get faster as the temp goes down. WST is the one I use for my 45acp.

 

[Tony k]

Use a reverse temp sensitive and it will get faster as the temp goes down.

Didn't know that was a thing. Seems to defy chemistry, physics, and thermodynamics. What am I missing?

 

[Blue68f100]

There are several powders that are reverse sensitive. Will see if I can find the list. WST is a fast burn powder similar speed as BE but it burns 10x cleaner, fluffy ball powder easy to see.

 

[Typetwelve]

I can't speak for reloads...but I can speak for semi autos and the type of lube you're using.

I run Enos Slide Glide on my semi's and love the stuff but I have to swap to Slide Glide Light in the winter or some of my tighter tolerance semi's will not cycle properly when the temps are low (you know...like it gets here in Illinois). I don't have a 1911 anymore, but when I did this was a major factor. A tight tolerance pistol and temp thickened lube = cycling issues for me.

 

[Texas10mm]

WST is the main powder I use in my .45 ACP loads.

 

[ATLDave]

As others have noted, it may not solely be a difference in how the powder itself is acting... your gun may be getting tighter and the lubricant stiffer. For cartridges that are on the lower edge of running the gun reliably, any of those factors can tip it over into malf-city.

 

[murf]

only the chronograph knows for sure!

murf

 

[lordpaxman]

We all know it does. I had it proven to me over the past few months.

How much though? You're saying in addition to all the other factors in reloading I need to account for temperature as well? You're getting me nervous, I love WST in .45. I would think if I'm near a limit it might be an issue, but I try to stay away from Max loads for sure, and at least make sure if it's a match load I've got a 5-7 PF margin. I also found this reference where someone did some testing and didn't see a strong correlation.
https://forums.brianenos.com/topic/14066-wst-and-temperature-sensitivity/
Maybe it's some fodder for a @bds myth?

 

[LiveLife]

Maybe it's some fodder for a @bds myth?

Oh, I have been keeping track of powder temperature sensitivity.

It's how I found out Promo is reverse temperature sensitive like WST/WSF - https://www.thehighroad.org/index.p...temperature-sensitivity.817116/#post-10473222

 

[lordpaxman]

Oh, I have been keeping track of powder temperature sensitivity.

But of course!!! By any chance do you have WST sensitivity data, and, any advice for it in .45? I've got data at 40F, but still waiting for warmer daytime temperatures!

 

[LiveLife]

Yes, WST is reverse temperature sensitive.

As you know, WST still holds smallest 25 yard 9mm group for me. I haven't used WST much for 45ACP as I fell in love with W231/HP-38 years ago with recent affair with Promo and my eyes are wandering towards Sport Pistol lately.

But since there have been so many new powders to test, I have not done any 9mm comparison to WST.

My bottle of WST has been getting lonely sitting next to WSF but perhaps I can at least do some cold weather chrono testing to compare to warmer weather summer testing.

 

[Dudedog]

An easy way to test if its warm/hot is to put some rounds in a zip lock bag and put the bag in an ice chest.
If it's cold warm them up with the car heater.

 

[Texas10mm]

I can't speak for reloads...but I can speak for semi autos and the type of lube you're using.

I run Enos Slide Glide on my semi's and love the stuff but I have to swap to Slide Glide Light in the winter or some of my tighter tolerance semi's will not cycle properly when the temps are low (you know...like it gets here in Illinois). I don't have a 1911 anymore, but when I did this was a major factor. A tight tolerance pistol and temp thickened lube = cycling issues for me.

The lube I use on my match 1911 is Lucas Gun Oil. Not the extreme.

 

[lordpaxman]

As you know, WST still holds smallest 25 yard 9mm group for me.

Oh... tempter of tempers... I’m a scared, not quite as brave as you guys since Hodgdon doesn’t seem to want to use WST in 9mm. I know there is older published load data and other data here on the forums, but there are a lot of other powders to use in the meantime. I am in the process of loading lots of .45 with WST for the revolver competitions and understand WST has this reverse twist and my data was taken at 40F, so I'm not sure what that will mean at 80F but I'll set some aside and test in the summer. I've got a 6PF buffer for the 165 minimum and wouldn't expect a delta of 40F would drop it below 165.

An easy way to test if its warm/hot is to put some rounds in a zip lock bag and put the bag in an ice chest.

Yes, but then I'd have to take out a few to make room, and then, I'd feel obligated to drink them as well! I'm planning on waiting for mother nature to fix the cold issue, and then retest. I have other WST loads that are associated with warm temps but didn't have the same stock to retest in cold temps. Is there any empirical data that can predict for a given load, what the temperature affects are? If someone says "QL does", and has found it tracks real data, then shucks, I'll just have to buy it.