What do you guys think about this?

This is Gibbs' design of a case that uses a threaded tube threaded into the web of the case around the primer hole. The idea was to direct the fire from the primer to the front of the cartridge to reverse the direction of the burning of the powder. This was suppose to give about 200 fps in a .270 Winchester, and was suppose to make it more consistent.

I bought a used mauser rifle that came with a set of dies. In the box of dies was directions and notes describing this whole setup along with the previous owner's load data using these cases. Very intersting. Does anybody have any experience with this setup?

There is a book out published by Wolfe Publishing, called "GIBBS A MAN AND HIS CARTRIDGES AND FRONT IGNITION TECHNIQUE". I came across thid book about 5-6 years ago. The front ignition section was acopy straight out of a book that Rocky Gibbs wrote himself. As I've been told, Rocky did quite abit of experimenting in this area and I heard that Ackley did some too. I also hear that this is not a new idea that the military uses this in some cannon shells. Although Gibbs was the only one that I've seen documentation on that applied it to small arms.

Now, have I tried it? Yes I've done some in 280 Rem cases. At the time I didn't have a chrono (its been a few years ago) and it worked. The cases were not difficult to create although they wouldn't last many firings. The flash tube joint with the case is the problem area. The load I was using was not a duplex load, just straight 4831. Pressures were low.

Now I've acquired a 240 Gibbs that I've got some good loads for and now I've become re-interested in trying out the flash tube on the Gibbs. Its extremly overbore for a 6mm and the loss of some case capacity wouldn't be much of a detriment. Thats the main reason I think this idea never got fully developed... Ray

In Elmer Keith's book "Hell I was There" he and one of his friends experimented with this and had good results. Higher FPS & lower pressure. Fuzz

Fuzz,
Wasn't Elmer dealing with a .50 BMG?
I need to reread that book again. In theory, you could eliminate the sandblasting effect from the powder. Also, it would make gas operated firearms much cleaner. They wouldn't have to rely on ball powders so much.

The main purpose of my interest in this modification was to reduce the sandblasting effect that the powder has on the throat. The 240 Gibbs is already an eroder of grand scale. So any help gets my attention.

The documentation, which was definately dated, that I've seen did show higher velocity with lower pressure. Did these guys have any pressure testing equip or are they just reading case indications. Makes me wonder. Sure would like to put an Oehler M43 to work on this...... Ray

Hello "Short",

I've had this level of dialog on a number of occasions with an "old friend back home". He "sold me" on the concept easily. I have always had a great deal of intrigue pertaining to this concept.

I think that from a production and cost perspective, it would add significant burden with touch points to every facet of the industry. This entails (a) additional components; (b) necessity of introducing "dynamic metrics"; (c) proper variant identification.

From an engineering stance, it has significant merit. (1) supports the notion that less is more; (2) direct & deliberate attempt at controlling specific variants (specifically the burn rate); (3) a simple solution to an age old problem (loss of energy and work).

The only precaution I can draw on at this time is Peretos' Law of Triviality - in which we are reminded to avoid situations where 80% of our effort to only yield a 20% effort.

Good stuff!

Best regards,
Alex

How do you de-prime the cases?
R-WEST

Alex, but, remember, 20% of the work yields 80% of the benefit.........

I think it would be a grand improvement, since some guys seem to be interested in buring twice the powder for 200 fps.

Aren't the cannon tubes perforated?

Dutch.

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For evil to prosper, good men must do nothing. (Burke)

R-West, In answer to your question of How do you deprime the cases. Obviously you cant deprime using the pin stuck in the end of the expansion ball. Take a long pin that will insert thought the tube to manually knock out the primer. Sizing the neck is best with a bushing die. But some conventional dies have a real short stubby expander ball that wont knock on top of the tube.

Whole case prep process with these cases keeps you thinking..... Ray