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Brass fireforming question
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I was out to the range last weekend and fireformed brass for my new 25Gibbs. Bye the way I would like to thank all who had input last winter when I was asking questions about this build up. Anyway I was using 55gr IMR4831 with 90gr Seirra hpbt seated into the lands, aswell I had necked new 270 Win cases to form a false shoulder to get the headspace right. The load is the starting load from Rocky Gibbs book (Max is 60gr). About 10 of fifty cases split at the shoulder the rest formed nice sharp shoulders. Is this a brass problem or a loading problem?

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Growler

 
Posts: 95 | Location: Alberta Canada | Registered: 23 March 2001Reply With Quote
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It's a brass problem. I'd anneal before fireforming to increase ductility of the brass which may have hardened in the forming operations.
 
Posts: 1261 | Location: Placerville, CA, US of A | Registered: 07 January 2001Reply With Quote
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I would agree that it's probably a brass problem, however, you rarely see new, unfired brass which is hard enough in the shoulder area to split in a fireforming operation like this.

Is the .270 brass too long for your chamber? I don't know, but am guessing that the Gibbs uses an '06-length case (2.49") rather than a .270 length case (2.54"); I'm sure that you've checked case length carefully, however.

Annealing can be tricky, and it's easy to get brass too soft. You might want to try a different lot/brand of brass instead.

 
Posts: 13235 | Location: Henly, TX, USA | Registered: 04 April 2001Reply With Quote
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Wait a minute! Did the Gibbs book call for IMR 4831? I would have guessed that his data would have been with original surplus 4831. There's a big difference in burning rate. You might want to check it out.
 
Posts: 13235 | Location: Henly, TX, USA | Registered: 04 April 2001Reply With Quote
<OKShooter>
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Growler -- My guess is that you are okay on the powder charge since generally a standard 25-06 maxes out at around 59 grs. IMR-4831 with most 90 grainers. At any rate, excessive pressure is more likely to cause leakage around the primer, leave a shiny spot on the head, or blow the primer completely rather than cause splitting at the shoulder.

Stonecreek made an excellent observation, though. I am pretty sure the 4831 load in Mr. Gibbs book is for the old surplus H4831, and the current cannister version appears to be a little faster burning than the surplus lots.

I think it most likely that some of your brass was a little more work hardened than the others. Annealing is an option. If you want, surf out to www.ammoloading.com and look under Advanced Topics and read the annealing article.

 
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The book I have is an edition/reprint from 1991 and includes IMR and Hogdon 4831 and 4350 as well as IMR7828 and RL19 and 22 in the load data for the 25Gibbs. I did have to trim the 270 cases to fit the chamber and the fired brass showed no signs of pressure at all. I was wondering if the load was too light but had a feeling it was the brass. I have neverhad this problem forming for an ackley 243 so I think I will anneal necks on the next lot and see if this helps. Thanks to all for the advise.

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Growler

 
Posts: 95 | Location: Alberta Canada | Registered: 23 March 2001Reply With Quote
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For fireforming my 6.5 Gibbs I have done it both ways. The first lot of 50 brass I used Winchester cases and a load of 47 gr IMR 4895 and a bulk 120gr Remington bullet. The powder charge was as per the book "Gibbs Cartridges and Front Ignition Loading". I lost one case out of 50.

The other way was with 50 R-P cases and a load of 11 gr of unique, cream of wheat and a toilet paper plug. I didn't lose any cases with this method.

I did not anneal the cases in either case. Forming the .25 Gibbs from .270 brass will not move much more brass than the 6.5, so I am kinda surprised to hear of so many lost cases.

For the .25 Gibbs, the book I have recommends a fireforming load of 50gr of IMR 4895 and an 87 grain bullet. As you said, you have to make sure to seat the bullet out far enough to engage the rifling so it will hold the head of the case back against the bolt face, and that the false shoulder is a snug fit in the chamber.

Hope this helps.

Canuck

ps: The max length of the case is 2.505, but should be trimmed to 2.494, the length of the standard '06 case.

[This message has been edited by Canuck (edited 12-13-2001).]

 
Posts: 7121 | Location: The Rock (southern V.I.) | Registered: 27 February 2001Reply With Quote
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The Gibbs cases have historically been a fireforming problem and that is the main reason they never were all that popular..Gibbs made a hydralic case forming tool that was a real piece of work in that it squirted oil every where when wacked with a hammer....

the best way to save the brass is to fireform the first time with Bullseye, kleenex wad and cornmeal then load a good load with a bullet....

It's not a brass problem per sae, it is the fact that you are moving the brass a long ways in a short time, not just blowing out a shoulder, and thats hard on brass and causes splits.

I shot the 30, 6.5 and 358 Gibbs for several years in the early 50's...that was the Gibbs short lived heyday.

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Ray Atkinson

ray@atkinsonhunting.com
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Posts: 41858 | Location: Twin Falls, Idaho | Registered: 04 June 2000Reply With Quote
<Burnt Powder>
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Ray Atkinson is absolutly correct in his explaination. If you want another opinion to concour, consider mine that opinion. Ray, you were supposed to use water not oil. It wasn't nearly as messy! Face it, the Gibbs will cost you about 10% loss in fireforming. Some lots less, some more! over the years plan on about 10%!

BP

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Speak softly, but carry a big stick!

 
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Burnt Powder,
It didn't take me long to figure that out on the Gibbs wildcats, I decided the Ackley was a better bet, then decided wildcatting was a very expensive game that I just liked to play, so I gave it up entirely, but it took half a lifetime to learn that valuble lesson....

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Ray Atkinson

ray@atkinsonhunting.com
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Posts: 41858 | Location: Twin Falls, Idaho | Registered: 04 June 2000Reply With Quote
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Ray & BP,

I'll admit that fireforming Gibbs brass is more labor intensive and time consuming than the Ackley versions (or the standard '06 versions) but when you put it in perspective it ain't that bad.

It took a full afternoon to fireform 50 cases for my 6.5 Gibbs. I've done it twice in 3 years and all 100 cases are still in very usable condition. It'll be a couple years before I have to do it again. Unless you plan on competitive shooting, your average guy will not have to spend much time fireforming at all. Once it is done, reloading is no different than any other cartridge.

And as for the cost, well Ray, I am sure you cannot say with a straight face that the bullets, cases, dies and/or rifles in your beloved 9.3's and .404's are anywhere near as cheap as my 6.5 Gibbs.

So stop trying to spoil our fun!

Canuck

 
Posts: 7121 | Location: The Rock (southern V.I.) | Registered: 27 February 2001Reply With Quote
<OKShooter>
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I didn't want to show my age too overtly, but since both Ray and Burnt Powder have fessed up to being old codgers, I guess I will too.

However, I only have experience with the 30 Gibbs, and very little of that. The rifle was a Remington M725 cut for the Gibbs chambering. I don't recall losing many cases during the fire-forming operation, but I used new brass (mostly R-P) and headspaced on the bullet.

 
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I was back at the range and formed some more 25 Gibbs cases I annealed 50 new Win cases and used similar loads. Not one split case. Now I will have to get on to serious load developement. Thanks to all for the input.

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Growler

 
Posts: 95 | Location: Alberta Canada | Registered: 23 March 2001Reply With Quote
<TGWoody>
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quote:
Originally posted by growler:
I was back at the range and formed some more 25 Gibbs cases I annealed 50 new Win cases and used similar loads. Not one split case. Now I will have to get on to serious load developement. Thanks to all for the input.


Growler,

Good going, what annealling process do you use to fix your brass?

Don't you love it when a plan goes together. :~)

TGW

 
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TG. I started annealing brass about a year ago and from alot of reading and advise for this board I go a welder friend of mine to get me a temperature crayon (it melts at a certain temp range) and i practiced in my garage with the lights off(my wife though I was crazy). I take deprimed cases and use my pirmer pocket uniformer and cordless drill to spin them. Now it is a matter of timeing and stopping just before the blue flame on the propane torch turns orange and i put the case in a pan of water. With practice I have become quite consistent at getting the temp right. Anyway this works well for me. I didn't think that new brass would require this but it only takes about 45 min to do 100 cases.

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Growler

 
Posts: 95 | Location: Alberta Canada | Registered: 23 March 2001Reply With Quote
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I've been shooting a 30 Gibbs for the last 11 years. Admittedly, the cases are a pain to make. That's OK--I just want to make sure that I don't get bored shooting cartridges that are too easy to get or to load for. Ray is right about fireforming--Bullseye and cornmeal are inexpensive and easy on the barrel. The cases can be fireformed from '06 cases by headspacing on the bullet, but I don't like putting that many bullets down the tube just to get cases. Also, case life seems to be a bit shorter with that method. I'd better go--I have 200 new cases to fireform!
Good Hunting.

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Andy Cooper

 
Posts: 6711 | Location: Oklahoma, USA | Registered: 14 March 2001Reply With Quote
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