Problem with .17hmr ammo. Anyone help me out?

[crazy_train04]

I had a box of Hornady .17hmr ammo in my truck for the last month or so that I keep in there for Groundhogs. Anyway I wanted to check my zero one day and found the ammo that has been in my truck was not shooting very good groups at all. At first I thought there was something wrong with my gun or scope.. I tried a fresh box from the local gun shop and they shot great zero just like they should. Does sitting in a warm place effect this type of ammo. The truck gets fairly warm inside on some days and I didn't know if this would effect the bullets accuracy? Maybe just a bad box of ammo??

 

[pc9]

I would get another box and try them out if they shoot good then only shoot half the box and leave the other half in the truck for a month and see if its the same.

 

[bigdawg]

i find my 17 is a picky eater u gotta find the brand she likes and stick to it

 

[crazy_train04]

I only shoot Hornady 17grain. This is the first box I have had out of 10 boxes that has given me a problem.

 

[cz452shooter]

Its possible that the heat could have caused that. I knw that the cold can affect the ammo and possibly heat is the same way. Be aware though that each lot is slightly different and if you sighted in with one box and then switched to a different box of the same brand (exact ammo) it could be slightly off if the lot number is different.

 

[redleg]

Yes heat affects both powder and primer compounds. Repeated hot/cold cycles also break down powder and primers even more quickly.
Ammo should be stored in a cool dry location and like wine it prefers constant temperature.

 

[crazy_train04]

Thanks alot guy!!
I will only keep 5 rounds in the truck for the odd groundhog in my travels.
The rest will stay at home in the cabinet.