I have to make some cases for a .25 Gibbs, which is a 30-06, necked down to .25, blown out and shoulder pushed forward, wildcat from the 1950s.

I'd buy cartridge cases from Quality Cartridge, but they haven't made the .25 Gibbs in three years, and I'm running out of patience.

I'd like to fire form the brass from .30-06 cases, of which I have plenty, but have never done so, and need some advice.

First, I'd prefer to form without bullets if possible, using wadding, corn meal or wax instead of a bullet. I'd also need to know how much of what kind of powder to use for this.

Same info needed if the only way to do this is to use use a bullet. How much, of which powder, for the fireforming charge.

As a finished case, the Gibbs will use a slow burning powder, because it is a big case, with a small bore, and is moving at pretty high velocity. From a capacity standpoint, the finished Gibbs is half way between a .25-06 Remington and a .257 Weatherby.



Here's a picture for comparison purposes. First, a 30-06, next, a .25 Gibbs case formed with shoulder, next, shoulder and bullet, then completed round, and a .223 for comparison.

I did not make these cartridges; they came with the rifle and dies when I got them, and the 7 or so stepped and loaded cases I got have split when I tried to form them. I haven't fired the finished case, as it is the only one I have, and want to keep it for measurement purposes.

There isn't much published information out on the web that I trust on this issue, and would like your input. Rocky Gibbs' wife burned all of his papers after his death, so there really isn't much to go on. When I do get cases, I will start with .25-06 load data and work up to a reasonable load from there.

I have read of a number of ways to do this on the web. Some posters suggest forming the step, using a bullet, and a reduced charge of the intended powder, but they don't say how much reduced. Some suggest using a bullet, not forming the step, jamming the bullet into the lands, and using a reducd charge. Again, no indication of how much reduced. Still others suggest a pistol or shotgun powder and a bullet, or, as noted above, powder, a buffer like corn meal and a wax plug.

I'm at sea on where to start with this, and could use some advice from the folks on here who I trust way beyond random information on the web.

Thanks for your help.

A

Excerpt from page 200 of Handloader's Manual of Cartridge Conversion:
Make from 25-06 Rem. F/L size the '06 case in the Gibbs die. Fireform in the chamber with light loads. Trim, chamber and reload.

Sorry, but it looks like a bullet has to die to make each of those cases.

The old way, as done in the 40s and 50s, was to load a small charge of pistol powder, Unique, or sometimes Bullseye, under a case full of cornmeal or cream of wheat. Usually this was capped with a small plug of canning parafin to keep the cream of wheat from spilling.Take it outside and shoot. I should think pistol primers would work as well as rifle ones. Maybe a good place to use up old ones, or those with questionable storage history. I would wipe the bore out after each shot, or at least check that there isn't some of the cereal left in the barrel. Good luck on your interesting project!

Yes, an interesting project, sounds rather uncommon.

I've fireformed several hundred 6mm Dasher cases. Formed from a 6BR case. Different caliber, same procedure.

If your 30-06 brass is not new, suggest to buy new brass. I FF'd a few pieces of used brass, split more then half the necks. Lapua offers 30-06 brass. Use it, best brass available. If you don't need/want 100pc box, buy individual pieces here http://www.brunoshooters.com/product/7738.html

.25 Gibbs looks easy to FF. Simply neck down 30-06 brass creating a false shoulder. Key to the false shoulder it needs to headspace in the chamber. Don't want the brass to move forward by the force of the firing pin, potential case seperation down the road. Lube up the case, slowly neck down with a non-bushing die, check it in your chamber. You're good when there's a reasonable amount of resistance on the last 30% of your bolt close. If you get new brass, experiment setting your die with old brass, get a feel. The when move to new, raise your die up in case the brass is not exactly the same, check in your chamber again.... With the Dasher I fireform with a 90% load of the parent case. I've FF'd as many as 400 cases for new barrels. I'm not going to mess with the pistol powder/cream of wheat method. Even if I was doing a few dozen cases, wouldn't mess with that method. Use a soft primer, Federal. If use a harder primer, chance the case will still moves forward a smidge when hit by the firing pin. My only concern with your caliber is how much you're necking down, guessing could do it in one step? Hope that helps.

I would also suggest you anneal the brass prior to any forming. This will help prevent splitting the brass out. I would even do it on new cases if I was fire forming. The softer the brass the easier it will fire form. On some you have to do it twice depending on how much you work the brass.

quote:

Originally posted by Blue68f100:
I would also suggest you anneal the brass prior to any forming. This will help prevent splitting the brass out. I would even do it on new cases if I was fire forming. The softer the brass the easier it will fire form. On some you have to do it twice depending on how much you work the brass.

From my experience FF'ing over a 1000 Lapua cases, no need to anneal prior to FF'ing. It is annealed from the factory. Not a bad idea to anneal after FF'ing.

Thanks very much for all the great responses.

Yep it is diff for each cartridge size, why there is little info. I have tried the pistol powder/cornmeal/wax pug. It works, but the case are not perfectly formed & I hesitate to cram more powder in. So I use the bullet method. Form the case sim to what you have done giving a false shoulder. Then us a faster powder from data of a sim case size, in your instance I would use 25-06. It is why it's called wildcatting.

I've fired formed for a handful of wildcats... and I'll be danged if I can remember.

IIRC I just began with starting loads, which don't always blow the case out all the way. But you won't know until you try.

Almost all mine are rimmed cases, so they're easier. The .375 Hawk/Scovill is the only one I need to make a temporary shoulder for.

The cream of wheat method was always too "iffy" for me, too much guess work, so I always just bought some cheaper bullets. (lighter bullets are usually cheaper, but in my experience don't work as well as heavier ones.)