.30 Gibbs
I just bought a rifle chambered for this cartridge. I haven't had much luck finding load data. So far, I've found a little bit in The Handloaders Manual of Cartridge Conversions and some in Cartridges of the World. (Some of it seems to be a little over the top!)
Anyone have any experience with this wildcat?
Anyone have any experience with this wildcat?
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I think there is some data in one of PO Ackley's book (I'll look later - I'm trying to get ready for elk season. I had re-heat treated Springfield punched out to 300 Gibbs. A short necked little body taper 30-06. I made my cases from 57 NM stock. I bumped the neck out to 8mm then sized it back enough to hold cast bullets for fire forming.
IIRC I just filled the cases with H-4831 and 165 BT. It was 2 grove barrel. The rifle shot as good as I could hold it. Easily in the top 10 most accurate rifles I ever shot. Never had or needed dies - the chamber was perfect. I gave it back to the guy I got it from, he like 8 kids to feed.
I think I would be looking for some T-870 or some other slow ball powder.0 -
Rocky Gibbs was active in the 50's. His specialties were standard cartridges, loaded with different types of powders. Loaded one on top of the other. That he claimed extravagant velocity gains for.
His data, didn't stand up to close scrutiny though. And his superposed powder loads, were ignored after awhile.
Do a chamber cast of your rifle. Likely it will be just a standard 30-06. Just put together standard 30-06 loads, from and any manual. Ignore the .30 Gibbs marking. And treat it just like, a standard 30-06.
EDIT #1,
Sorry! Just looked the 30 Gibbs up, in COW. He didn't use the standard 30-06 case. He rechambered the 30-06, to a "blown out case with steep shoulder and short neck".
You are going to have to, fire form 30-06 brass. And full length resize, with a custom resizing die. Doubtful that standard 30-06 dies, will work sat with a Gibbs chamber.0 -
Ambrose,
As rufe-snow points out, Rocky's cases were the extreme of 'Improved' case shape and capacity. He, like so many others in the 50's and 60's, was looking to push the envelope of velocity and energy with case improvements. Rocky's signature ultra short neck was simply an example of just how extreme.
Graf & Sons has one set of Redding dies on sale right now.
I suggest casting the chamber before starting any reloading program. Be sure you have the Gibbs chamber before attempting any reloading because case failure can be a little scary...
You will have to neck .30-06 cases up to 8mm at least and .338 would be better. Then neck the case down to .30 cal. a little at a time until the case chambers with a very slight resistance. Now the headspace is at the shoulder location for Rocky's shape. Start with normal .30-06 loads to blow out the case shape and solidify the headspace. The pressure will go down since the case is expanding to fill the larger chamber.
There is a brochure available through some of the reloading scalpers which is a copy of Rocky's original brochure touting his cartridge line. Yes there are more cartridges featuring the shape.
Best.
ADDED:
Excellent illustration of the case evolution!
Best.0 -
I met and talked to Rocky Gibbs a few times. I also knew Ray Tarbox, guide and outfitter out of potlatch ID.
Ray used a 6.5 gibbs rifle. Loaded H4831 in TW brass till the primer hole expanded, than dropped the load one gr. and used DEN 42 & 43
brass. Springfield 1903 action and 26" barrel.
You can read about it in the book on wild cat cart. Brings back good memories. I worked as a packer for Ray on some elk hunts.0 -
This might help. 
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I think there was a Gibbs in every caliber you could get bullets for at the time. Same case body and shoulder.
As I recall from old articles he recommended specific headstamps of GI and NM brass for strength and durability.
He said a case should last ten loadings without expanding the primer pocket, so any listed load should not be considered a strict recipe.0 -
At the time I talked with Gibbs he recommended Den 42 or 43 brass.
I don't know what the brass you would use today. This was in the 1960s.
As advised, work up a load with care.0 -
quote:As I recall from old articles he recommended specific headstamps of GI and NM brass for strength and durability.
He said a case should last ten loadings without expanding the primer pocket, so any listed load should not be considered a strict recipe.
quote:I don't know what the brass you would use today.
The brass you could use will limit the loads by the method of the case being manufactured. We all know that some cases are built strong while the opposite end of spectrum leaves us with cases which will not standup to higher pressures.
When I was working on a couple of Gibbs projects, I used some National Match brass I had on hand then switched to Lapua because of availability. Testing by standard method is what's important. Start low and work up slowly always watching for signs of pressure. Be sure to use a chronograph as well.
Remember, Rocky was trying to make a name for himself and sell products so anything he states is open to being suspect to a certain extent. Ackley was in the same boat... Go slow and be careful.
Best.0
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