Originally Posted by EdM
Originally Posted by ingwe
Learned the same lesson, but not as harshly, with a .223AI and H335. Shot GREAT here in Montana at 40 degrees. First and only shot with it in Texas at 90 degrees blew the primer, End of H335....

Exactly the same experience here with the same round and powder.

I tested my TAC loads on a hot day as hot as I knew I would get the gun(s) in question. They failed and I ended up getting safe results with an extruded powder.

They were both 1-14 twisted guns with 40gr. bullets and I'm betting ingwes loads were too.

Its about pressure at the chamber and heat generally makes it go up if you're already at max.