Does brass expand with each reload?

[SLOMountaineer]

I say yes and have had it happen. A friend says no because the resizing die compresses it again. I bought som re-manufactered ammo once that didn't seat all the way in my Camp 9 but was far enough in to fire. The rear of the cartridge blew off and blew the stock, etc. to smithereens. I checked the rest of the ammo and there was a bulge near the base in all of them that was visible to the naked eye.

From that point on, I don't buy remanufactered ammo and I only reload my brass once, twice with carefull inspection.

Am I right or wrong?

[Stargazer]

A lot of, "how many times to use a case," is determined by caliber, how many times it has been shot, whether it is a pistol or rifle case, etc. I am reloading and shooting 45 ACP cases that are 30+ years old and reload and shoot just fine. Been shooting and reloading my .357 cases for 2 years now and have had only (1) nickle plated case split on me.

Like you on certain calibers I will load hot rounds with new cases only and then they go in the lighter load pile. That is with my Ruger BH 45 Long Colt. Same for the .357, hot loads in new cases, maybe a medium load in the next reload and then they go to the lighter load pile.

I do not purchase remanufactured rounds either unless they come from a very reputable source and lately I just reload all of my own, period. Not just for cost savings either, it's good therapy! When you are reloading you try and usually do not think about much other than the task at hand. Kinda takes the mind off of the days worries.

[Hawg]

Brass expands to chamber dimensions. The sizing die brings it back to unfired condition however it will stretch lengthwise. You're wrong to toss your brass after only a couple of reloads. Check length every two reloads and trim if necessary. It sounds like an overload. if it had not fully chambered it shouldn't have fired at all.

[FM12]

The round probably headspaced on the rim held in place by the extractor, and fired out of battery (not fully chambered). The resulting explosion outside of the chamber is what did the damage.

Full length sizing usually solves this. Watch for the dreaded "Glock bulge", which may not be removed by some sizers. This, at least in theory, weakens the case at the bulge.

[Slamfire]

A Camp 9 carbine is a blowback action. I am not familiar with the details of the design of that weapon.

It is highly likely that your round did not seat completely flush into the chamber.

A case simply provides a gas seal. The chamber supports the case and prevents the thin sections from rupturing.

In a blowback, the bolt starts to move the moment ignition occurs. The bolt moves slowly enough that the barrel/breech pressure has dropped to safe levels before the thin parts of the cartridge are pulled out of the chamber. I would guess that your cartridge was not supported properly in the chamber because it was not fully seated. So as the round is extracted, thin sections of the case were exposed at a time when the pressure was too high.

That's my guess based on your statement that the cartridge bases were swelled.

Normal remanufactured brass goes through special sizing rollers that resize the case heads to factory dimensions. This equipment is massive, could probably roll a telephone pole into a toothpick, and is too big and too expensive for a homeowner. I am surprized that the case heads were oversized, something must have been wrong in the process.

[azredhawk44]

Brass expands to chamber dimensions. The sizing die brings it back to unfired condition however it will stretch lengthwise. You're wrong to toss your brass after only a couple of reloads. Check length every two reloads and trim if necessary. It sounds like an overload. if it had not fully chambered it shouldn't have fired at all.

Yes and no.

In an unsupported chamber, the brass will expand at the base, outwards. Heck, even in a fully supported revolver chamber, I've seen a 44 case that has had too many instances being loaded with 296 begin to loose its shape at the base.

My friend has a Ruger .40 caliber handgun and matching PC carbine, and I wonder about case support on that particular setup because his ammo has horrid bulges on the base. His dillon sizing die does not fix this problem.

And frankly, my Lee/RCBS/Forster dies don't size COMPLETELY to the bottom of the case either. In any caliber I own. I'll admit I don't own a small base die, however. Never tried one.

I just threw out 50 pieces of PMC 44mag brass that just didn't look right even after re-sizing. They had 5 loads through them, probably 2-3 of those with H110 or Win296.

To the OP:

they get longer (especially rifles, but all cartridges in general) when fired. You can trim them back and keep using them, but then they get thinner. At some point, they get thin enough that they will bulge at the base, or suffer from a case head separation.

Or you can avoid that problem and get rid of them before they fail you.

Some calibers will last years and years. I have .45acp cases that must have 10 loads through them (never trimmed), and they will be chucked because the extractor beats them to heck, not because of bad lengths or thin-ness or bulging.

My .308 from my M1A is a great example. It has to be trimmed every 2-3 times it is fired. I trim twice (once with new brass, once around load #3 or 4). On the fifth loading, they get tossed. Were it a bolt action .308 the brass would last longer, but the rifle is murder on the brass. Mostly because the brass is extracted while still burning hot and still expanding from the pressure of the charge.

I'd be comfortable reloading 9mm cases at least 6 times as long as I wasn't using max loads and I was not seating my bullets deeply or using excessively heavy bullets (147's for example). with reloads, I try to get the minimum amount of power to reliably cycle my action, unless it is a 44mag hunting or critter defense round. As a result, my handgun brass lasts a long time.

[Unclenick]

Some cartridges, like .45 ACP, actually get shorter with use. The dividing line is right around magnum pressure levels (which full-house 9 mm is at). It is when the pressure gets high enough to stick a case to the chamber wall harder than the pressure needed to stretch the web of the case to take the case head back against the breech face. The case head is getting to the breech face one way or the other. In the lighter loads the whole case moves rearward getting blown Aout shorter and fatter. I once tracked a batch of .45 ACP cases through 50 reloading with target loads; 3.8 grains of Bullseye under 185 grain hard cast SWC's. They shrank an average of half a thousandth per reloading and wound up about 0.025" shorter at the end.

Some bulging in an unsupported case is not unusual. A lot of bulging and splitting is not usual. This bulge is in the lower half on just one side. It should not be confused with a slight bulge cause by the base of the seated bullet.

[SLOMountaineer]

they get longer (especially rifles, but all cartridges in general) when fired. You can trim them back and keep using them, but then they get thinner. At some point, they get thin enough that they will bulge at the base, or suffer from a case head separation.

Maybe that is what happened with mine. Whatever the cause, it didn't chamber all the way but was far enough in to fire. My friend next to me felt a splinter skin past the tip of his nose.

Thanks for all the input here, lots of good info.