Shooters Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
629 Posts
Discussion Starter #1
Hello,

In all my years of handloading, I've never been able to find information about the increases in balistics achieved by Rocky Gibbs' Forward Ignition system. I've read that there was a statistically significant increase in velocity with it.

I've decided to try it out for myself by preparing 50 cases and loading them with a standard load for my rifle.

I need small diameter brass tubing and small tap and die tools to install the tubes. Any suggestions as to where I might find these items?

Lobo in West Virginia
 

·
Super Moderator
Joined
·
3,375 Posts
Years ago, I fooled around with forward ignition in a .35 Whelen, and found the small diameter brass tubing appropriate for forward ignition tubes at a local refrigeration service/repair center. Had to make a small collet type tool to hold the tubes for threading into the threaded flash holes.... kind of a pain until I finally got the proper configuratoin down, then it went like clockwork.

Taps and dies galore at McMaster Carr.

www.mcmaster.com

Pretty interesting stuff. I got some really interesting results, but in all fairness I'm not sure whether the increases in velocity were due to my young, rather nieve indifference to pressure differences, or actually generated from improved powder burn characteristics utilizing the forward ignition tubes.

Oh, by the way, I also found the most expedient way of decapping forward ignition tube equipped cases, was using an RCBS Berdan decapping tool. It allowed decapping the case without removing the flash tubes.

Let us know what you discover in your quest!

God Bless,

Marshall
 

·
Registered
Joined
·
629 Posts
Discussion Starter #3
Marshall,

Thanks for the resources!!

Do you recall the size of the tap and die threads you used when you were doing this?

Yes, statistically significant might only be 50 fps increase in velocity, but we shall see. I've got a copy of Gibbs book outlining the general process. It leaves out the details. He does claim to have loaded his .30 Gibbs with a 180 grain bullet faster than a factory 150 grain bullet, however, not all of this gain came from front ignition! I have ten fingers and two eyes and intend to keep them.

Lobo in West Virginia
 

·
Registered
Joined
·
416 Posts
That idea has always intrigued me, but I never got around to trying it. I'd be real interested in your findings.

DC
 

·
Super Moderator
Joined
·
3,375 Posts
Right off the top I don't remember what size the taps and dies were for the forward ignition tubes, but I'll do some digging into old records and see if I was thoughtful enough to write all that info down.... I was pretty lax about record keeping in those days, throught I had a GREAT memory.... perhaps I did then, who knows.

I'll check.

God Bless,

Marshall
 

·
Registered
Joined
·
639 Posts
When Elmer Keith refers to his "duplex" loads, this system is that he was referencing. Keith did not mix powders, despite what many people claim.
Best results with the forward ignition seem to occur in overbore cartridges with heavy bullets and long barrels. It's not surprising that the .35 Whelan didn't show great improvements. Something like the .264 Winchester Magnum would be a better candidate. The U.S. government initially tried the system in the .45-70 and noted no performance increase at all.
Part of the attraction for this system originally was the limited powders handloaders had to work with. With the current choice of powders available, you may see even less improvement.
Be very careful with the forward ignition system. There are a lot of little tricks to it and it's entirely possible to have unexpected pressure spikes and blow a weapon. This is one of the reasons that Keith finally abandoned it.
Three of the tricks I can recall offhand are to neck size only, so that the body of the cartridge can't expand much in the chamber. Make absolutely certain that no powder gets into the ignition tube (this is why the forward ignition tubes in artillery rounds are capped with cardboard). Load density of 100%+ is desirable.
Please let us know how your experiments turn out. :)
 
1 - 6 of 6 Posts
Top