Loose Primer pockets

I ran Federal brass when working up loads for a 7mm rem mag. I found 66.0gr of RL22 with 140gr TTSX to be my sweet spot. Which is also max load. I got approx 4 more reloads out of that brass before 4-5/50 would have loose primer pockets.
Ive shot some rounds with loose primer pockets with no issues. But with that said I am now switching to WW brass to try and see if I can get a few more reloads out of them.
My opinion is the hotter the better, Im a horsepower kinda guy. Barrels are cheap.
You said your running Hornady brass? I run Hornady brass in a 243win, running 0.8gr under max load with Varget and have 8 reloads on that brass with no issues yet.
(Whoever is picking up all the used Federal 7mm rem mag brass up from the Lloydminster gun range is going to be very disappointed LOL)
 
I read somewhere, and I believe it was from Norma, that if your first firing of brass is a moderate load it will "work harden" your brass and make your primer pockets last longer. Conversely when you fire factory ammo it is loaded for high velocity which is not helpful for maximum brass life. I have somewhat tested this with 300 wby brass (Norma made) and pockets losen up on factory ammo brass faster than when I take virgin brass and shoot the first shot at a medium load.
 
Scott......what you are seeing is that Horn brass is softer than a lot of others and their weights are all over the map. Your loose primer pockets, I'll wager weigh as much as 10 grns above the average of the lot and I have found this to be very prevalent in Horn and FC cases. So needless to say your case capacity is diminished by having more brass and less powder space, hence your pressure is elevated. My suggestion would be weigh all your cases and discard or use a lighter load for any that weigh more than 2 grains over the norm. This will allow you to continue to use your tried and true load in those cases of appropriate weight and you can get some plinking from the heavy weights or just scrap them when they no longer hold primers. When you go to replace that lot of brass I might suggest you look for Lapua or I personally use W-W...........I will not use Horn or FC in any rifle I own.......PERIOD.
 
One reply I see here, was that a person has a load "below book max" that is loosening primers in 3 rds. That is still a high pressure load that probably should be reduced a bit. Remember that the load in the book, is what they found in the test rifle, not yours, yours may be close, may be higher, or may be lower pressure with those same loads, and if you change a component, brass or primer, you can toss the book load. You have a different chamber and throat to the test rifle, that is something you can count on. The books are a guide, nothing more.
 
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