30-06 Flash tube - Front Ignition (Sectioned)

Retrieved: 08/27/2016 [all pictures were 404]

Many of the early US patents for forward ignition can be found in the citations for this patent:

http://www.google.com/patents?vid=USPAT5090327

historian
Jun '08

Here is .50-70 that I have in my collection, one of the Treadwell experiments from the 1870's. It is unusual in that not only is it a front-ignition cartridge, but the anvil extends nearly the whole length of the priming tube. Plus, it uses a coiled case.

Although it may be impractical for small-arms ammunition, it has been successfully used in many large-bore rounds. Both the 105mm and the 120mm APFSDS rounds used in the US use a lengthened primer tube. I'm sure many other countries make similar rounds.

historian
Jun '08

Cyber,

You are correct that there are advantages to frontal, or mid, ignition in artillery cartridges. And even in some very large capacity small arms cartridges such as the 50 calibers.

Many mistake the primer in an artillery case for a frontal ignition tube, which it is not. Even our own IAA Glossary incorrectly labels a primer as a "flash tube".

That's a GREAT cartridge BTW. A one-shot deal I suppose.

Daniel,

You are correct. Flash tubes take up powder space. Any imagined ballistic advantage is usually offset by the reduced case capacity. Claims of increased velocity and/or enhanced accuracy have never been proven beyond a few anecdotal examples. But the facts do not keep shooters from re-inventing the idea every few years.

I guess I leave no doubt that I am a skeptic when it comes to frontal ignition.

Ray

historian
Jun '08

Ray, It is my understanding that the cases you display are the "OKH Duplex" cases. They date from the 1930's. Charles O'Neil, Elmer Keith and D.S. Hopkins are the "OKH". O'Neil patented the design (US patent 2269316, application July 5, 1938, granted Jan 6, 1942). Patent claims increased velocity with reduced erosion. The US patent does not make any mention of duplex powder charges. There was a short magazine article years ago (I think it was an interview with Keith, but don't quote me on that) where it was mentioned that they had had some .30-06 cases adapted by Luft Bros of Spokane as part of their tests. Interestingly, O'Neil filed a Canadian patent at about the same time (Canadian patent #409,954, granted Jan 12/43) assigning the patent to the "Duplex Powder Company" of Menahga, Minnesota. I never found out anything about this company though it is possibly that it refers to a company that O'Neil set up or planned to do so. In the Canadian patent, O'Neil lists his address as Menahga, Minn. Both the US and Canadian patents illustrate what appears to be a .30- 06.

historian
Jun '08

Chris,

I'm familiar with most of what you iterated. When I was writing my short JOURNAL piece on flash tubes I did some patent searches on the O'Neil patents and was surprised to learn that he experimented with several different methods of attaching the tubes.

It is possible that Luft Bros did the work for OKH also but I was under the impression that they (OKH) abandonded the concept before Luft was making the cases. They would be more in line with Rocky Gibbs' era.

But I'm only guessing.

The "Duplex" load concept that you mentioned is a mystery in itself. OKH did experiment with it but it's my understanding that the two concepts - Duplex powder charges and frontal ignition - were completely seperate ideas and not used together in any one cartridge. What I have heard is that Elmer Keith, who worked for the War Department during WWII, was involved in a secret project involving frontal ignition and that the cover up was using the term "Duplex Loading". Since most were familiar with the OKH experiments along those lines they would naturally add "Keith" and "Duplex" and come up with the wrong answer.

But, we'll never know for sure, will we?? Anyone interested in espionage and conspiracies would have a field day with this one.

Ray

historian
Jun '08

Here's another method of installing flash tubes.

It is very similar to the first except that it can be recognized from the outside. This time the entire primer pocket is drilled and tapped, but to a larger diameter, as much as 3/8 inch or more. Instead of a simple hollow tube, a complete unit is fabricated and installed, consisting of a new primer pocket and flash tube combined, often of stainless steel. This method is somewhat stronger than the first, is more easily installed, and also permits the use of a primer different in size than the original, if the user so wishes. The second photo shows such a case with the primer/tube unit removed.

This is a 334 OKH (wildcat) cartridge. But don't jump to any conclusions. It's not an OKH job. Just a coincidence. This method is also used in cartridges such as the 50 FAT MAC.

Ray

historian
Jun '08

Ray,

Is this the same Luft, (Luft Brothers), that made the .285 Luft Magnum, as seen in the Speer Wildcat Rifle Loads booklet?

Thanks,
Dan

historian
Jun '08

sam (Dan) ?

Yes. They had several wildcat cartridges. They were one of the premier gunsmith and shooting shops in the Pacific Northwest.

I'm not sure when they went out of business but I went by the store in the 1970s and was impressed. Back then I was interested in guns and not cartridges so missed out on acquiring some good ones. (I don't think it was still the Luft Bros in the 70s but my memory of that far back is failing)

Ray

historian
Jun '08 Ray Meketa:
What I have heard is that Elmer Keith, who worked for the War Department during WWII, was involved in a secret project involving frontal ignition and that the cover up was using the term "Duplex Loading".

In one of his books, Keith mentions experimenting with front ignition .50 BMG rounds during his Ordnance Corps stint during WW2. I believe it was in "Hell, I Was There!"

historian
Jun '08

Here is the flash/ignition tube for a "sectioned" 90MM (1945) and one for a 105mm or 120mm (new in the late '80s). The 90mm is 3" tall and 1/2" OD; is flanged/rimmed and pressed in from the base through an enlarged primer hole as a primed unit. The 105/120mm is 12" tall/7/8" OD which screws into the base through the mouth of the hull. A seperate primer is screwed into the base. The 105/120 was/is manufactured by Kilgore Manufacturing in Toone, TN. They are a huge supplier of Phalanx 20MM assembled components and manufaturer of those aircraft flares and systems you see being ejected by assorted US Mil. aircraft. As well as some other pretty neat stuff. But I digress. These "flash tubes" are facilitators of ignition vs the front ignition/higher performance claims afforded by the .30-06 and lesser calibers. The large grains of the bigger rounds require a much more aggressive starting system created by a mini-explosion to get things going. Very impressive devices (the105/120mm at least) when set off by themselves.

historian
Jun '08

Rick
I believe that both of those are tecnically primers.

The primer for the old 5" cases can be a complicated affair but it's still just a primer.

Ray