.30 Gibbs DRIVING ME NUTS!!

[Cain R]

Had my Savage '06 rechambered to .30 Gibbs, basically an improved '06.

First trouble fire-forming. The info I have suggests a case forming load of 50 gr IMR-4895 and a 180 gr bullet seated out to touch the lands, okay fine, first three cases, new '06 Norma brass, nearly complete case head seperation.

So, next fireform load, 50 grs IMR-4350 165 gr bullet seated to touch the lands, and new Winchester brass, success. Hmmm, excpet for the noticable bulge at the case head. After cutting open a few to check it looked like there is no seperation just a tiny bulge, a couple of more experience wildcatters said not to worry, its normal, okay.

First shot with 62grs IMR-4350, 165gr bullets (moly coated Hornady Interlocks) a load 4 grains under the published max that I have, showed almost complete head seperation about 1/8" above the bulge. Okay enough with that.

178 gr Hornady A-Max, 65grs H-4831SC, is giving me three shot groups of .635", .769" and the best, .468", BUT, one in three cases is showing a severe bulge and when cut open the very plain indications of soon to be case head seperation.

Now, what am I doing wrong??? Is the published data way too hot, for my rifle, or am I doing something wrong in the fire forming step? :banghead:

 

[HerbG]

Are you sure the person doing the rechambering checked the rifle's headspace? It sounds like a headspace problem to me.

 

[Jim Watson]

Herb, the Gibbs case has a quarter inch neck, steep shoulder, and no body taper. The shooter has to make the case fit the chamber headspace.

Cain, all I know about Gibbs calibers are what I read in Ackley. From what he says you might try fireforming a few with the bullet seated out so far as to ram hard into the rifling, not just touching. You must hold the casehead back against the bolt as the round fireforms.

Another trick that has been suggested is to expand some case necks way up to .35 or .375 cal and then size back down to .30 just far enough back down the neck for it to chamber and headspace on the false shoulder.

Now I remember why I don't do wildcats any more.

 

[Wil Terry]

AHHH YES...ROCKY GIBBS, VIOLA IDAHO

His spirit lives on, pissing off rifleman from the great beyond.

 

[BigG]

Some of the old wildcatters used to fire a case full of powder topped off by cornmeal to fireform their first cases. Mmmm. New cases and muffins all in one. /homer simpson

 

[Grump]

I'd always heard of fireforming being done with significantly backed-off loads, like 25% down from max, or even pistol powders. Cornmeal makes sense there.

The case neck or ogive-ram idea sounds good, too.

 

[BigG]

It probably was a load of pistol powder because it burns fast. Look up Elmer Keith or P.O. Ackley to find out the details.

 

[Jim Watson]

I did look in Ackley.
The usual technique was to pull the bullet from a factory load and reseat it very shallow so it would be hard into the rifling over the standard powder charge. Ackley said that with a CRF action you could just let an unaltered factory load headspace on the extractor and that he had fireformed that way in a P17.

The false shoulder technique was usually done with other caliber Gibbs (or other wildcats) where you would be expanding or reducing the neck anyway.

WARNING: That is what P.O. Ackley said, I haven't tried it or seen it done.

 

[BigG]

Savage prbly ain't CRF. The load in a non-CRF would have to hold the headspace by the bullet jamming into the rifling thereby keeping case head against boltface. Otherwise, the case head separation problem is likely to continue.

 

[wes382]

i may just be 15 but the way my dad dose it is with shotgun powder and corn meal

 

[Jim Watson]

When I was 15, I could type with correct spelling, capital letters and punctuation.
Back to school, wes.

 

[JackOfAllTradesMasterAtNone]

Now now Jim.. That was Wes's first post. Don't scare him off now. I'm happy to see any 15 year old here, digesting and providing information in a respectable manner. Better here with typed words instead of chat short text than playing a video game, or out tagging freeway overpasses.

Wes, Ur welcm her Ne tim.


I don't have a 30Gibbs... But I do fire-form my 30-338's from 338winmag brass. Of course this is a belted cartridge. I neck size, short stroking. I seat the bullet out to the lands using 60% of my normal/hunting charge. TWICE for each case using cheap Nosler bulk seconds from my local gun shop. (using cast lead 30-30 bullets would work fine too) The first firing I end up with little ripples at the shoulder. The second firing eliminates the ripples. Subsequent loads are neck sized to the full length of the neck with full power powder charges.

I have experienced separation, but that was when I was trying to fire-form all in one step. Have you ever watched a Blacksmith work a piece of hot iron into a boot spur? Does he/she get the metal red hot and smash it with a big heavy hammer? No the iron would crack. A little hammer -working the metal, just as a Baker neads bread dough or a pie crust until it reaches the correct consistency and shape desired.

I would have your .30Gibbs chamber cast with Cerosafe. You can learn a lot from doing this.

Take a look here:

http://shootersforum.com/showthread.htm?t=5690&mode=hybrid

http://www.30gibbs.net/forum

 

[Jim Watson]

Yeah, you're right. At least he has the excuse of being young. There are enough adult semi-literates on the net without that to fall back on.
Do you reckon Cain has figured out how to fireform his brass in the past four years?

 

[JackOfAllTradesMasterAtNone]

Oh.. Now that gives me a chuckle! I didn't even look at the date of the post. :banghead: Well, hopefully someone else that's contemplating owning a wildcat has read this and figured out that it might not always be peaches and cream. You know, If THR would send posts older than six months to an archive, maybe we would have this resurection of old posts less often.

-Steve

 

[Jim Watson]

"owning a wildcat has read this and figured out that it might not always be peaches and cream."

Truer words were never spoken. I read a lot of posts about wildcats coming out of the closets as shooters of the 50s and earlier die off. You are just buying a lot of aggravation trying to resurrect one of them. The gun, not the shooter.

Of course the factories are doing that to shooters now, with the current crop of niche cartridges.

 

[Oohrah]

Met Rocky back in the 60s and he had printed out stuff on all
his calibers made on blown out 06 cases with 308 length necks.
Being new to wildcat stuff I was told to shoot as is, 30-06. Like
your partial separations on the first go around.
If your chamber was poorly done and is oversized nothing can be
be done except an a larger diameter upward rechamber to one of the
belted Mags. However, my cure to perfect forming, and never loose
a case is this. I use a moderate load of 4831 powder and a gas checked
180 grain cast 1 in 10 lead bullet. The bullet is seated long enough to have
a CRUSH fit when the bolt is turned down. The above ensures that
there is no forward case movement as the firing pin drives forward to
ingnite the primer. With out the crush fit, the case is diven forward,
and as the expanding case travels to the rear to be stopped by the bolt
face and chamber walls. Once formed, I prefer using the heavier GI
stuff, but commercial and Winchester will hold more powder. It definately
lets you know it is there with heavy bullets.
Rocky Gibbs did not do my Springfield 03, but a a couple of smith partners
from Milwaukee, Wisconsin (L&M Firearms) who have been out of business
many years now. I suspect that Rocky in Idaho may also long gone. Most
likely none of his stuff will ever be adopted by any firearm company like
the 25-06. Personally I like my 30 Gibbs and feel it's enough gun for deer
through bear and elk . Actually it isn't a difficult case to load once you
get a few fire formed cases Heard of a guy that does this and also a hydralic
way, but can't confirm either.