Gibbs and/or Ackley claimed military 30-06 ammo was fired in either a 98Mauser or an Enfield wildcatted to 30Gibbs without any case failure (I think 200-300 rounds). I have an Interarms Mark X (basically a commercial 98) and want to know what the realistic and/or worst scenario would be if I fired 30-06 ammo through it as well (nothing, case separation venting gas into magazine, gun damage, etc.)? BTW, measuring with calipers, head to shoulder is 2.110" (.035 shorter than AccuLoad specs) and head to neck is 2.195" for my Gibbs (.057 shorter than AccuLoad specs, difference from .035" could be precision problems using calipers).

Deke.

A lot of people used to fire-form .30 Gibbs cases from .30/'06 brass by seating the bullet out long enogh to jam it solidly into the rifling. This was supposed to hold the case back against the bolt face solidly enough to prevent case rupture from the obviously excessive headspace situation caused by the difference in the shoulder location. However, I have never heard anyone suggest that it is OK to try to fireform '06 brass to .30 Gibbs by simply firing UNALTERED factory .30/'06 ammo in a .30 Gibbs chamber!! DON'T DO IT -IT IS POTENTIALLY VERY DANGEROUS!! "case separation AND venting gas into magazine, gun damage, etc.!!! YES!!



On the other hand, it's OK to fireform .30/'06 AI brass this way, BECAUSE THE AI AND THE STANDARD '06 HAVE THE SAME HEADSPACE MEASUREMENT!! Only the shoulder angle and shoulder diameter/case taper are different on the AI.



The only safe way to fireform .30 Gibbs brass from .30/'06 empties is to first neck them up with an 8mm or .338" expander, then reneck them down gradually to .30 until you can just barely close the bolt on the re-necked case before you load the fireforming charge and bullet into it. Or you could start with .338/'06 or .35 Whelen cases!!



The best alternative would be to use a hydraulic forming tool like old Rocky Gibbs developed, and reform surplus G.I. '06 brass with it. However, remember G.I. brass generally has about 2 grains less capacity than commercial cases.

What Eldeguello said---extremely bad idea! I did it exactly once about 15 years ago and got a split case with a separated head.....the case head, not mine. All I got was a mild heart attack when I saw the case.

There is a good possibility that the extractor would hold the case providing something for the case to headspace against. I have done this with pistol powder and filler. However I don't believe I would do it with full factory or military loads. If I had military rounds I wanted to form brass from I would see if I could pull the bullet out far enough to give a headspace. Or pull the bullet expand the neck and then reform a false neck and reload.

Why risk the rifle or yourself??

The .30 Gibbs might not be all that great, but I believe the .338/'06 mwould be an excelent candidate for rechambering to the Gibbs conformation. If I live long enough, I may get around to trying one.....

First of all, I fireform using 10gr pistol powder and filler and it works very well. 95yjcoup, what cartridge and action were you using when you had that separation? I will note that this is something that I am not going to just run out and do. Gibbs or Ackley (I am too lazy to dig through the books) did it and I have wondered about it since reading that. What kind of rifle damage would there be? I would think that there would be less pressure since the brass has further to expand into and with the Mauser the gases should discharge safely into the magazine.

Deke.

I was just looking at Gibbs book "Front ignition Loading" in it he states if you are going to use factory ammo the bullet should be pulled and the bullet seated to engage the rifling. So I don't know what you read. As to your question of damage it would be a head speration due to excess headspace. While loud they are not normally that distructive. The 98 or MkX vent system should handle most of it without major damage. I have no experience with the Enfield

As I said I did at one time just use the extractor to hold the case during fireforming with pistol powder. What I found in mine was there was just enough play that when the firing pin struck it would kick the front of the case over. Giving me a case that was just a little lopsided. It would straighten up on the second firing. So now I always neck up and then form a new neck to headspace against. For me it gives a better looking case.

I shot a Gibbs for some time, and I had a set of hydralic case formers from Gibbs, and that was a joke...I made cases by fireforming with Unique and cornmeal, then shooting a bullet to get my brass...the whole experience was a exercise in futility..you can get the velocities he claims but at extremely high PSI, in fact you can do the same thing with a standard 30-06 at the same dangerous PSI....

Gibbs was a dreamer and his stuff wouldn't fly....If you want more than an 06 can give you, then rechamber to a 30-338 or a 300 Win Magnum...

Atkinson,

I agree that the hydraulic case former seemed like more than I wanted to get into and I have stuck to the pistol powder & grits.

However, I have to disagree that you "you can do the same thing with a standard 30-06 at the same dangerous PSI...."

Granted the 30-06 is an awesome cartridge to reload. However, a larger case volume with an improved shoulder design whether it be Ackley or Gibbs will give you more velocity and better case life at the same PSI. Maybe the more is not worth it to some.... W/180gr bullets I am able to safely (10+ case life) load my Gibbs up to handloaded 300RSAUM velocities (100fps faster than 06). Nosler #5 using a Lija 24" barrel for both the 06 and Ackley shows the Ackley 113fps faster than the 06. Comparing it to the Wiseman 24" barrel of the 300RSAUM, Nosler #5 shows the Ackley 22fps faster. Though this is not an earth shattering difference and the animal would probably be just as dead, it is significant.

I am getting off the subject a little bit, but I would not recomend a rechamber of a good 30-06, but would not hesitate to recomend a 30Gibbs or 30-06 Ackley for a rebarrel. You get 300RSAUM velocities (which are on the heels of the 300WinMag) with the same or a little less powder than the 300RSAUM and about 10% less powder than the 300WinMag. Plenty for big Muleys and mature Bull Elk at any reaonable range.

Deke.

hmm, i am thinking this is a FINE use for matchkings or ballistic tips and some 296 or bluedot...

set it out as far as possible and send that AMAZING bt into a clay bank.... even *I* won't argue that the BT is a fine bullet for that

jeffe