I know that as brass is repeatedly resized it will harden. And to the point that some will anneal their brass. My question is will it harden so much that after full length resizing, it will "spring" back somewhat and be larger than expected?

I ran into an issue where brass that I've repeatedly fired was a bit snug after FL resizing. Factory ammo did not do this.

When brass hardens, it will be less likely to spring back.

A couple of things could be causing your "snug" brass. You may not be bumping the shoulder back quite far enough. Also, full length resizing is never able to size all the way past the web; if the case is expanded there, the fit would be snug. Also, if the brass was longer than it should be, that could also cause a snug fit.

What cartridge, by the way?

quote:

Originally posted by Grumulkin:
When brass hardens, it will be less likely to spring back.

A couple of things could be causing your "snug" brass. You may not be bumping the shoulder back quite far enough. Also, full length resizing is never able to size all the way past the web; if the case is expanded there, the fit would be snug. Also, if the brass was longer than it should be, that could also cause a snug fit.

What cartridge, by the way?

300 Win Mag. Just measured the brass I shot and all but three were less than max. Those exceeding were just .001-.002 over.

quote:

Originally posted by Grumulkin:
When brass hardens, it will be less likely to spring back.

A couple of things could be causing your "snug" brass. You may not be bumping the shoulder back quite far enough. Also, full length resizing is never able to size all the way past the web; if the case is expanded there, the fit would be snug. Also, if the brass was longer than it should be, that could also cause a snug fit.

What cartridge, by the way?

I think you got the brass thing backwards. If it's harder its more springy. Dead soft brass won't have as much spring back. Many cast bullet shooters that use gas checks anneal the gas checks so they are dead soft. The reason when they size them along with the bullet they don't spring back as much as the harder ones. The problem in some instances with the harder gas checks is that spring back so much that often the rest of the bullet is loose in the case neck because the fatter gas check sized out the neck a little.

Sounds like the fellow doesn't have the sizer die adjusted right and basically was just partial sizing the cases which is very close to neck sizing only. With neck sizing after so many firings you eventually have to full length size the cases again.

You can smoke the shoulder slope of your fired cases and size one see if the die is touching the slope at all. If not smoke more cases and keep adjusting down the die until it just makes contact with shoulder slope. Then resize the ones that you used to do the test. You should be okay then. Those mag cases are suppose to head space off the belt on them, but many size them to head space off the shoulder with will prevent a head separation. If you size the shoulder back to far and the case does head space on the belt, then the brass can develop a separation.

Smoking the case isn't a bad idea. It would tell you if the problem is at the case shoulder or elsewhere on the case.

If the problem is because of insufficient sizing near the web, this die might help you:

Collet Resizing Die

I have said die and have never had to use it but your situation may b a little different.

If you are using the brass in just one gun I would neck size only and trim to length.

quote:

Originally posted by Trap4570:
If you are using the brass in just one gun I would neck size only and trim to length.

That's a plan. If that is what he does he'll eventually have to full length resize them.

In the old days there were dies in common use which WOULD size cases all the way, including the web area.

They were the L.E. Wilson Chamber-type full-length sizing dies.

They used no shell holders. The whole case was pressed or hammered into the die, using a special base plunger and a hammer or arbor press. The base plunger came as part of the set.

The sized case was removed from the die with an ejector punch which also was hammered or arbor pressed in at the other end of the die to get the brass out. It was also part of the set.

They once were available for all the hunting rounds. I still have them in 7 & 8m/m, .270, .30-06, .300 H&H, and numerous other chamberings. Unfortunately, for most hunting calibers, I doubt if they are still available.

Just another instance of a correct, usable, simple tool we "ignorant" old timers had which the "modern reloader" doesn't even know much about and almost never sees. The were pricey to buy and slow to use, but they worked to do reloading jobs which modern tools simply can't.

Ain't progress grand?

agreed, AC. The best we can do these days is a small base die. I anneal all of my rifle brass the second time it is fired; and once-fired military as I take it out of the box. You just know any brass was likely fired in sloppy chamber machineguns.

Rich

quote:

I ran into an issue where brass that I've repeatedly fired was a bit snug after FL resizing. Factory ammo did not do this.

Factory brass is at its softest AND smallest, it gets harder and larger as it's used. Dead soft brass has NO springback, the springback does increase as the brass gets harder. FL dies are commonly made small enough to accomidate a rational amount of springback in most chambers over the life of the cases but there are exceptions to everything.

There are two probable possiblities to account for your difficult chambering.

One, you don't have the sizer screwed down quite far enough to set the shoulders back properly; that's the most common cause.

Two, some belted cartridge dies just don't size the body down quite enough just ahead of the belt. The Innovative Technologies collet sizer will correct that problem.