Cracks in the brass

[WinterSoldier]

Have you ever checked the head space on that gun? Your brass is failing in the area that is worked the most if the brass has to expand quite a bit to fit the chamber because the bolt closes back further from the case head than it should. Both neck sizing only, since you are using his brass in one gun only, and annealing should help. Bringing head space into specifications, if it isn't, will help, too.

HOWEVER, the reloadability of brass varies greatly. Some factory loaded military brass is notorious for coming split. Turkish 8mm and Bulgarian 7.62x25mm Tokarev come to mind... but they are both Berdan primed and not candidates for reloading. Sellier and Bellot (S&B) commercial rifle brass is well-known for being good for about 3 reloads. S&B pistol brass is as reloadable as any other brand. The main cause of brittleness of rifle brass in the neck and case mouth area is working it back and forth... firing stretching it and resizing pushing it back together. Annealing addresses this but does not extend case life to perpetuity, and supposedly doesn't help at all with S&B rifle brass. Rifle brass also stretches and thins in an area close to the rim... and when it stretches too much here, that's that. Reducing loads helps extend the useful life of brass. Firing hot loads reduces its useful life.

[substratum]

All of the split brass is WW brand. I've got about 150 spent WW and Remington shells that I'm going to reload. I've watched the Youtube videos on the topic - it looks easy enough, and i purchased a propane torch yesterday.

Next question, which I didn't see addressed in the video: Should I run the shell through the resizing die first (before annealing), or should I anneal first, then resize?

If this next batch splits the brass, I'll have the headspace checked.

[WinterSoldier]

I don't know what the youtube videos show but for your purposes I would think to anneal then resize would be the best order to follow. Depending on what purpose the youtube video annealing was for, you might anneal less of the case. You never want to heat the entire case down to the case head because you don't want that area near the head softened, but if you anneal to fireform cases to a different caliber you might need to anneal more of the case than if you are just annealing to prevent neck and/or case mouth splits. I've fireformed quite a few .303 Brit cases into .410 musket shot shells and if there is any unevenness of heating down the side of the case it can manifest as a very lopsided .410 case until it's fireformed again or fired with shot. I've also annealed new brass in several calibers made by Bertram in Australia, because they make it thin and brittle... and other new brass just because it was so damn expensive. I've used the propane torch and pan with water method (and eventually bought a Lazy Susan to help with that though I've not annealed any that way since buyng it) and the hot lead annealing method too... and you better believe me when I say that if you forget to oil the case before you dunk it in molten lead you're going to end up with one hell of a mess. It is my impression that if you have already fired the brass a few times the effectiveness in terms of additional firings you will get from annealing will be less, but frankly so far as I know just about everything written or said about annealing for reloading is at least as much subjective or hearsay as "science". It all depends on the unknown nature of the brass you start with, the unknown characteristics of the specific gun, load, etc. You get whatever you get. But, it's an interesting exercise. I'm more certain of the product when fireforming to change calibers... because you start with one thing and end up with something else. When you anneal to make brass last longer, the results take longer to evaluate and the evaluation is more subjective.

[WinterSoldier]

Headspacing Mausers is an interesting exercise. It must be presumed that when the gun & bolt were mated at the factory headspace was within spec., but with an elderly military firearm with a matching bolt the headspace could have increased, and with the many military Mausers out there that come with mismatched bolts the only thing you can rule out is that it's not too tight if the bolt closes properly. In addition, the 7.92mm Mauser specs. have changed slightly and two sets of headspace gages are made for them, varying slightly by date of manufacture of the gun. The practical difference is very little, but that little might include some small difference is case reloading life.

[substratum]

Annealing, then resizing seems like the most intuitive approach.

The annealing video had you put the brass into a tall socket - just large enough to hold the case, and spin it on a drill while heating the brass from about 5mm below the shoulder up to the neck. They were heating them for <10 seconds, and the "done" test was how the brass changes color. The purpose as stated in the video was exactly what Jim suggested in the first response to my OP... to make it less brittle.

[WinterSoldier]

I should have said this in the first place: Citing "Youtube" as a source is almost meaningless. It's only one step above citing "the internet" as a source, and two steps above citing "some piece of paper with writing on it." In a sense, when us hoi polloi take up discussing subjects such as the metallurgy of an alloy like brass, we are all completely over our heads. It doesn't help, though, to be accepting some guy whose claim to fame is owning or borrowing digital video equipment, then running his mouth about something he may or may not know anything at all about... as an "authority" on the subject... any subject!

So far as I'm concerned, though I make no pretense of being an authority either, whoever the guy in question is, may have handed you half a ball of wax. I think that if you look further into the matter... some place more authoritative than "some guy on Youtube"... there are two aspects to annealing cartridge brass: (1) evenly heating the appropriate part to the correct temperature, then (2) quenching. Heating alone will soften the brass. Quenching restores a certain amount of hardness, but without the brittleness that existed before heating. As a part of protecting the case head from becoming soft, it sits in water so that it never gets very hot... then the moment the part of the case that is being annealed reaches the target temperature, it is tipped over into the water and quenched.

At least, "That's my story, an' I'm stickin' to it."

It may well be that your Youtube guy includes quenching and you just didn't mention it. But... your synopsis sure doesn't sound like quenching is even possible using his "method". I f you can't be bothered with providing a specific URL to the specific video you are referring to, though, I can't be bothered with looking at random videos till I think MAYBE I've found the one you are talking about...

Sure, I look at Youtube videos too... and pseudonymous internet posts. But when it comes to holding something that goes "BANG" in front of my face, I sure do like to depend on something somewhat more authoritative. It appears to me that you are about to turn your brass to mush.

[substratum]

It's a production by Ammosmith.com. They do the quench, I just failed to mention it. These guys do a bunch of videos related to brass forming, bullet casting, etc., in cooperation with a publishing company that produces many shooting and sporting magazines.
https://www.youtube.com/watch?v=kgD5D0Wzu-c