AMMO SPEED CHANGES WITH THIS WEATHER

[TRSR8]

A test with Center-X I did 7 years ago showed the X did much better being warm than cold. It was about the same time of year as it is now that left a box of X in my refrigerator over night and kept it cold in a small flexible cooler with some dry ice. The other box of X I let acclimate to the ambient temperature (`85°F). The warm X's had an average MV 1107. The cold X's averaged an MV of 1086. While the cold has some effect of slowing the powder burning, I think the bigger effect was what the cold did the the lube on the bullet (a combination of both, most likely). The difference also showed up on targets where the warmer did better than the cold.

Ran the same test at the same time with CCI Standard Velocity and the results were, surprisingly, just the opposite.

Just thought I'd throw this out there. Take it for what it is.

Cold kills match ammo performance….a well known fact a why sanctioned matches are over about now. Too much heat, also a killer. Much below 50 deg is usually a waste.

 

[TRSR8]

In 22lr, humidity, not temp, is your deciding factor.
Normal 50-90 degree temps ammo varies accuracy wise little to none.
Dry low humidity, high damp humidity make the difference regardless of temp.
A damp humid barrel shoots faster as the moisture helps as a lube in a 22lr and a chronograph will confirm this. Temp change swing at eqaul humidity will show little if and change.

A factoid for you. Makes zero difference what temperature/ humidity you shoot, your barrel develops condensation during shooting.
Don’t believe me, shoot any time you want, immediately run a dry patch down bore, touch it to your lips….,behold how wet it is.

 

[VLNBYR]

And what about the other 15 or 20 shooters there at the same time, isn't their ammo affected the same as yours?

 

[dusterdave173]

And what about the other 15 or 20 shooters there at the same time, isn't their ammo affected the same as yours?

yes
Yesterday everyone groaned on the first card
I decided to swap to another ammo I had and for whatever reason it responded well and I went on to success

I just want to try and label what happens and not guess wrong It is the hardest part—seeing and understanding exactly what is what If I react based on a wrong assumption then I just get more in the weeds

Right now I am working hard to understand how conditions/ weather affects ammo performance. I am observing swings in ammo ability and performance with the recent changes in weather.
Good winning ammo suddenly goes to mediocre and other ammo stands up and shines then two weeks later , weather changed ammo wakes up and drills

 

[searcher]

Interesting thread. I was thinking about this argument on shooting temperature affecting accuracy. It brought back memories of my putting engine cases for motorcycles in my oven, while putting bearings to be installed in them into the fridge or freezer. Often times, the bearings would just drop in with no pressing required. Think of the barrel as being the hot element and the bullet the cooler element - or a cold barrel and hot ammo. It is the minute changes in internal and external dimensions at play here. I think when a barrel gets really hot and the accuracy goes to hell, it is automatically dismissed as internal stresses in the barrel at play. Seems logical that if the inside diameter of the barrel is slightly larger due to heating - things are going to behave differently - including the velocity - which might change enough to knock one out of the node? The condensation issue is one I've not heard of before. Now I'm not going to sleep tonight wondering about that....

Got me to thinking a test is in order to set the same ammo at different controlled temperatures (maybe at 20 degree increments?) and firing it, recording the velocities at each temperature setting - with the barrel at the same temperature (the tricky part). This might be a verifiable test of sorts if the barrel was also at the same temperature differential as the ammo? Hmmm.

 

[TRSR8]

Interesting thread. I was thinking about this argument on shooting temperature affecting accuracy. It brought back memories of my putting engine cases for motorcycles in my oven, while putting bearings to be installed in them into the fridge or freezer. Often times, the bearings would just drop in with no pressing required. Think of the barrel as being the hot element and the bullet the cooler element - or a cold barrel and hot ammo. It is the minute changes in internal and external dimensions at play here. I think when a barrel gets really hot and the accuracy goes to hell, it is automatically dismissed as internal stresses in the barrel at play. Seems logical that if the inside diameter of the barrel is slightly larger due to heating - things are going to behave differently - including the velocity - which might change enough to knock one out of the node? The condensation issue is one I've not heard of before. Now I'm not going to sleep tonight wondering about that....

Got me to thinking a test is in order to set the same ammo at different controlled temperatures (maybe at 20 degree increments?) and firing it, recording the velocities at each temperature setting - with the barrel at the same temperature (the tricky part). This might be a verifiable test of sorts if the barrel was also at the same temperature differential as the ammo? Hmmm.

22 barrels shooting match ammo don’t get hot, let alone really hot.
i’ve shot matches of 25 shots + sighters in under 4 minutes….bbl not even warm to the touch.