300 win mag
 

I have a 300 win mag and I do my reload I use 180g SST Hornady and H4831, 70g, 2900f/s, my problem is just I can not reload the brass 3 to 4 time, after that the primer pocket is enlarge and can not hold the primer, I try different primer but I have the same result, I have a friend he have a 7mm rem mag and he have the same problem, I thick is a problem witch the belt magnum.
Some body told me that I was over load the charge but I using the specification for the data books
if some body know what I am doing wrong let me know please

All loads listed in a manual, may not be safe in all rifles. If you read the manuals, they do advise starting with the minimum load and working up, while watching for pressure signs. Those loose primer pockets after a few firings, are a pressure sign. The cases are now scrap so start again with less powder in new cases.

That load is well under max published loads but the loose primer pockets are clearly telling you they are over max pressure. The exception is federal brass which will often show loose primer pockets very early and even with min book loads. There are so many potential causes for this, from bullets seated to far out or too far in to copper build up in the barrel to using 4350 when u think it is 4831 that it is near impossible to help. If you are loading your friends 7 mm too then the cause is likely related. I have 7 and 300 mag that have been loaded warm 8 or .ore times and the primer pockets are just fine. You need Eed to find a well experienced reloader in your area and have them help you out, right down to watching the full reloading cycle as u do it.

I use federal brass, before I use H4350 62g now I am using H4831 70g, last week I got a new powder Hybrid 100 and I load the first 20 at 60g to see what happen

Clarification I do not load my friend load, he do it by himself, I have not idea how he reload his 7mm WM, just we have the same issued with my 300 win mag and his 7mm rem mag

Federal brass is garbage. Anything but federal is better. I do two loadings on federal brass with my 300 wsm then throw them away.

thanks to know this, Federal brass are not really good,
this is my data in the reload

first load...good
second load ….good
third.... load I lost 10% to 30% of 100 brass
fourth... load I lost 70% of the remaining brass
so on the fifth load I have only 10 to 15 good brass, good for one more reload and after that garbage

is total different to my 308 I reloaded and reloaded and reloaded that I have not idea how many time I reloaded and steal good

My normal standard is no noticeable difference in seating primers after five firings, using a hand primer. Not talking about the case still holding a primer, but no significant difference in the force required to seat the primers.

So you have confirmed you are using Federal brass. As long as you do, the loose primer pocket issue will be with you. IF your friend is using Federal brass too, then you know why you have a common problem. Switch to Remington, Winchester or pretty much anything but Federal brass and the loose primer pocket issue will go away.

yes my friend is using a federal brass to,

Thanks for you comment , I will change the brass to see if can fix this problem

How long has this issue with Federal brass been around? I have one batch that is from the late 80's and lots in the past 10 years or more.

Sig

I have 200 Brass 300 WM purchased in July last year, after that problems start on the primer pocket, I was thinking to chamber the barrel 300 WM to 300 WSM just to stay away from the belt magnum

The belt isn't the issue, you can have the same issue with non belted cases.

Adg Atlas makes quality hard and uniform brass. Check with big horn or rps international in spruce grove

Quit smashing your brass back to minimum size.
Set your dies for 0.002” to 0.003” shoulder set back.(Partial Full Length Sizing)
We can blame the brass all we like, but over sizing the brass is likely causing your brass to stretch and grow, and thus pre maturely cause your primer pockets to stretch, because let’s face it the cases have to fill the chamber and all that brass comes from someplace.

Here’s a video on the subject.
https://youtu.be/3hGvUzj7Zuk

Sorry Dick but on this one you are wrong. Over sizing brass causes lots of problems but expanded primer pockets isn't one of them. No matter how much you undersize it you aren't squeezing down the belt or the rim diameter.

I have had this issue with my 2 X 300 Win Mags as well, two things, CCI 250 primers appear to fit tighter than Fed 215GM primers so you may get another load out of the brass, second I just ordered some brass from ADG (Bighorn Sales) and they are claiming more "meat" in the primer/belt area so it may lead to some more reloads. There are some great articles where gents are getting 10 loads out of the brass. Now take this with a grain of salt but it does look encouraging.

Last week I reload 50 ammo with 150g SST Hornady and powder Hybrid 100 @ 60g, after I shoot it all at the range I lost only 2 of 50 (5 reload) this is a good improvement

nosler brass. two thumbs up . would like to try out adg as well. i read some where its the brass gunwerks ammo uses. its a bit cheaper than nosler.

I scored ADG Brass from Bighorn sales, was about $200 Canadian for 100 rounds in nice orange ammo boxes. So far very impressed with the consistency of the rounds/brass.

Spruce grove iswhere to get adg. Nosler is good but not in the same class. Give joe at RPS a shout.

You bet, I tried Joe and he was waiting to get his shipment in. Will get them next time from him.