Mr. Longbeard

What is annealing???

bigcountry

Annealing is heating the necks to around 600F. There is alot of contraversy on what temp to anneal too. Some say recrystalization won't happen until over 630F and some say below. Some say your just stress relieving.

I use heat sensitive paint like finger nail polish to know when I should throw in water. It softens the brass back up. Shooting several times works the brass and makes it brittle and then accuracy can go, and grip on your bullet is inconsistent.

bronko22000

BTM, As everyone else has said, its not the powder. And judging from the looks of the case, these have been loaded several times. Also, this is not neck splitting but case separation at the web. You said it was a 22.250 case, You didn't fire it out of that 300 savage did you?
The 22.250, like all cases, stretch upon firing (some cases more than others) which is why you need to trim you cases. The brass actually flows forward toward the case mouth causing it to weaken at the web, right where your cases are splitting.
Now, in order to minimize this and extend your case life, you may want to consider neck sizing your cases only rather than full length sizing. I would start with new brass (get rid of all your old stuff). Full length size it and load it up with your favorite load. Then after that, neck size only. Your cases should last longer.