Author Topic: Brass life (Read 902 times)

gdolby · « **on:** February 11, 2004, 07:16:18 PM »

Good day, with a mid range load how many firings can I expect out of my brass? thank you for your time....B

KN · « **Reply #1 on:** February 11, 2004, 08:02:00 PM »

What caliber? KN

gdolby · « **Reply #2 on:** February 12, 2004, 08:02:40 AM »

DUH! guess thast info is kind of need to know. 7 mm rem mag/63.5 IMR 4831 w/ 150 noslers

Robert357 · « **Reply #3 on:** February 12, 2004, 08:12:04 AM »

This is something that I would also be curious to learn more about. I have often heard that for rifle ammo, you should count on say 3 to 5 reloads and should check with a sharpened paperclip when you see any sign of a "ring" around the case head.

My personal experience with 30-30 and 30-06 is much, much higher numbers of reloadings, but I don't load to "max pressure" loads on anything.

My "gut" feeling is that how much you need to "trim" brass to the proper case length after each firing, is a clue as to how much the brass is probably being redistributed away from the case bottom or base (case head separation).

I have never had a case head separation, but I have thrown away brass with cracked cast necks and primer pockets that seem sloppy and large.

I am now doing some reloading with Winchester metric 7.62x54 R brass and doing a little more case trimming than I have been use to with other cartridges for near full power loads, so this question now has my interest. (Although, I am now switching to reduced cast bullet loads, so I expect that the amount of trimming will start to slow down a bit.)

As to pistol loading of brass, gosh, I have reloaded a bunch of 9mm, 357 mag, and 32 acp so many times, I have lost count. I have looked at trimming the brass on these handgun cartridges and found that after the initial case trimming, the is hardly ever a need to shorten them. Again, very seldom, do I load to the maximum pressure.

I seem to crush the rim on more cases by not belling the mouth enough for jacketed bullets during the bullet seating operation than I loose to case neck splitting. But I have to toss a few away because the neck splits. Again, no case head separation ever and I have some 32 ACP S&B (cheap brass) that I have reloaded maybe 50 times or more.

I suspect that if I were reloading Weatherby Magnum rifle rounds, things might be much different.

skb2706 · « **Reply #4 on:** February 13, 2004, 06:35:27 AM »

In my limited experience I would say you will have adifficult time determining that until you actually get started. Chamber dimensions, loading/sizing techniques play a huge role in case life. In my modern bolt action rifles in magnum calibers I figure on 5........in my custom chambered barrels of moderate calibers I can get many times that....25-30.
Handgun calibers of the .38 - .357 mag variety I have some like Robert357 said that have been loaded many times...no idea.

gdolby · « **Reply #5 on:** February 13, 2004, 06:42:10 AM »

good day sir, thank you for your time. the reason for my question is I'm getting cracked cases at 4 firings so Im not to far from your estimate of 5(shooting a 7 mag). thank you again and good shooting.

Robert357 · « **Reply #6 on:** February 13, 2004, 09:03:44 PM »

gdolby;

If I could ask questions in three areas.

First, where are the cracks in the cases? (neck, body, case head? do the run parallel to the case long dimension or parallel to the base?)

Second, when you trim you cases after each shot do you trim off much brass each time? If so can describe how much?

Do you full length resize or just neck resize?

Thanks

PaulS · « **Reply #7 on:** February 15, 2004, 06:02:40 AM »

With mid-pressure loads you should get a lot more firings than five... try a bit less sizing or neck sizing your brass. I don't find case problems until they have well over thirty firings on my brass. I nech size only the first half of the neck and keep pressures in the middle range where my accuracy is best. I don't get maximum velocities this way but the accuracy more than makes up for the missing velocity.

PaulS

Robert357 · « **Reply #8 on:** February 15, 2004, 02:43:01 PM »

Out of curiousity, I looked up gdolby's load of 62.5 grains of IMR 4831 for a 150 grain bullet, and it appears to be beyond max pressure load in my 2nd edition of the Lee Modern Reloading and the 5th edition of my Hornady Reloading books.

If that is the case then 4 uses of the brass may not be so bad after all.

rickyp · « **Reply #9 on:** February 15, 2004, 05:02:06 PM »

I have now gotten 10 loadings out of my 375 jdj brass with no signs of splits
out of my 7x57 96 mauser i normaly get about 3 loadings before the necks split.

I have never been able to really tell how many times I have loaded my 9mm i get over 15 loadings
45 colt is about 5-8 times out of a 45-410 contender
357 magnum is about 5-9 times

Most of my hunting loads I only get no more then 2 loads.
1 fireforming load and 1 field shot

gdolby · « **Reply #10 on:** February 15, 2004, 07:45:04 PM »

good day sir, been away for a few days apoligize for my late reply.the cracks are at the case head and run parallel to the belt.after the second firing I trimmed about 1 in 5 for 2 or 3 thousandths. The load manual that I went by developing this load is nosler 5th . they went from 60 to 65 grains. I loaded 5 rounds at the even grain and then at the half. out of the 11 sets that I loaded only 4 were under 1 and a half inches. the load that im using put all 5 in under an inch from outside to outside. that is why I do not want to change my load. Thank you for your time and interest. shoot straight B

gdolby · « **Reply #11 on:** February 15, 2004, 07:47:36 PM »

good day sir I have been reading up on changing my sizing practices. what is your opinion of annealing? thank you for your time.shoot straight B

The Shrink · « **Reply #12 on:** February 16, 2004, 01:50:42 AM »

gdolby

What rifle are you using? This sounds to me like you may have an overly large chamber rather than a problem with the cases. The number of times you can reload a case has to do with how much the case flows upon firing. If you have a tight chamber there isn't much room for flow or stretch. If you have a large chamber there is more room, thus more movement of the brass.

Wayne the Shrink

gdolby · « **Reply #13 on:** February 18, 2004, 12:47:14 PM »

good day sir. The chamber was my first thought also and I had it measured. It checked out to be good. the rifle I'm using is a 7 mm rem mag in model 700. thank you and good shooting..B

John Traveler · « **Reply #14 on:** February 18, 2004, 01:40:20 PM »

In military rimmed bottle-necked calibers (such as 7.62x54, .303 British, etc) and the belted magnums (7mm Remington, etc), chamber length is often longer than necessary. In the military calibers, this was a design feature to allow chambering of dirty ammo under battle conditions. Since these cartridges headspace on the rim, and reloading of fired brass was not a consideration, sloppy chambers often result.

In the belted magnums, headspace is established by the belt, and not the shoulder.

Full-length resizing of such cases usually results in case head separations after as few as two or three firings. There is not much you can do about it except to avoid full-length resizing.

HTH
John

The Shrink · « **Reply #15 on:** February 19, 2004, 01:16:13 AM »

John

He's talking about longitudinal base cracks, not case head separation.

This one's got me stumped, which I admit is not hard. Gdolby seems to be doing everything right and to have anticipated each of our suggestions.

Gdolby

I still think I'd want a mold of the chamber at this point. It's easy to do, you can do it yourself, and then get precise measurements of each and every aspect of that chamber.

It's either that or you just got a bad lot of brass. Somehow I doubt annealing it is gonna accomplish much. It's maybe worth a try given everygthing else you've been through, but you'd have to anneal the whole case rather than just the neck, and then you risk extraction problems, with maybe a case stuck in the chamber.

My $.02, for what it's worth.

Wayne the Shrink

John Traveler · « **Reply #16 on:** February 19, 2004, 05:16:26 AM »

Shrink,

Gdolby is indeed talking about HEAD SEPARATION cracks. His previous post describes them as running parallel to the belt, close to the head.

My previous comments about long-shouldered chambers stands.

John

The Shrink · « **Reply #17 on:** February 20, 2004, 01:20:34 AM »

John

You're right, my misread.

Wayne

Iowegan · « **Reply #18 on:** February 20, 2004, 09:07:28 AM »

I'd bet there is a slightly oversized chamber in your 7mm. Don't let it bother you if you are getting nice groups. Brass is pretty cheap considering. Most belted mag brass don't get more than 5 loads anyway. You're wise to cull the potential head seperation cases. If you ever get a case seperation where the head ejects and the body is still in the chamber, you won't be happy.

gdolby · « **Reply #19 on:** February 22, 2004, 10:31:32 AM »

thank you for your time and knowledge. What started all this was the situation you just described. lucky me I have a very good friend that has been reloading for about as long as dirt has been around and he saved me. thanks again and shoot straight