OP, it sounds to me like you aren't lubing the inside of your necks before resizing. That's a common mistake and I've been caught on it myself, even recently, when I was in a rush to reload 50, once fired, 338-06 cases made by necking up 30-06 cases previously.
It happens.
Magnum brass can and often does harden much faster if pressures are at or near maximum. They should be re annealed after 3-4 shots IMHO.
People have their favorite components but I don't get overly excited about anything, other than Lapua brass.
I use a lot of range brass, a lot of it is Federal and it works well in most situations if I'm careful to do my part.
Unless it's obvious that the brass is once fired, usually indicated by the shiney cases and brass colored primers, I re anneal all range brass, after washing it to clean up the crud.
I put it all into a heavy cloth bag and then into the washing machine with Lemshine and a couple of diswasher detergent packs. Brass may not be shiney but it's clean, inside and out.
Lots of folks don't like the way I re anneal but I've got 65 year old Dominion 30-06 cases and 75 year old Winchester 303 Brit cases that are still going strong after a lot of reloads, involving neck sizing only and being fired in the same rifle.
I heat up the oven to it's maximum temp then put all of the brass I'm working on, into it for 15-20 minutes, then take it out and let it air cool.
I used to quench it but that didn't soften it as much and it was pointed out by folks here that I was actually hardening it.
I was duplicating a procedure I witnessed at a commercial reloading facility in Brazil during the mid seventies.
Some of those Dominion cases have over 60 reloads on them.
