Mikecr
Well-Known Member
I'll start with context just opposite of this discussion: The 30-06 Springfield.
I'm risking offense, I know, but truly this cartridge represents everything poor in cartridge design.
It has a long powder column, high body taper, 17.5deg shoulders, overbore even while relatively large in caliber.
On firing, a significant portion of unburned powder is compacted into a slug which travels down the barrel against the bullet, adding driven mass. That powder slug ignites at muzzle release, causing a big ole flash, backfiring down the bore to cause secondary pressure spiking, and slapping the back of released bullets. There seemed nothing to stop this from happening, except to invent every improved .473 casehead cartridge for the past 113yrs. That's worked better.
But Gibb's described a counter, front ignition, to ignite the powder column at the front. This, containing powder burn inside the chamber(instead of down the bore & muzzle). Much like (and probably better than) short/fat columns with low body taper and high shoulder angles.
This was not solely for 30-06 of course,, I just needed to start somewhere..
In function, front ignition is provided by extending the flash hole ~2/3 into the powder column -with a flash tube. It would be easy enough to make, but not so easy to reload.
I'm thinking depriming would need to be done externally with a corkscrew type primer puller (like corks from wine bottles). A flash tube could be plugged to prevent powder entry using a finger rolled ball of flash paper. Stuff like that.
The tube would reduce capacity that much, so the case should be a chosen with this in consideration.
I'm risking offense, I know, but truly this cartridge represents everything poor in cartridge design.
It has a long powder column, high body taper, 17.5deg shoulders, overbore even while relatively large in caliber.
On firing, a significant portion of unburned powder is compacted into a slug which travels down the barrel against the bullet, adding driven mass. That powder slug ignites at muzzle release, causing a big ole flash, backfiring down the bore to cause secondary pressure spiking, and slapping the back of released bullets. There seemed nothing to stop this from happening, except to invent every improved .473 casehead cartridge for the past 113yrs. That's worked better.
But Gibb's described a counter, front ignition, to ignite the powder column at the front. This, containing powder burn inside the chamber(instead of down the bore & muzzle). Much like (and probably better than) short/fat columns with low body taper and high shoulder angles.
This was not solely for 30-06 of course,, I just needed to start somewhere..
In function, front ignition is provided by extending the flash hole ~2/3 into the powder column -with a flash tube. It would be easy enough to make, but not so easy to reload.
I'm thinking depriming would need to be done externally with a corkscrew type primer puller (like corks from wine bottles). A flash tube could be plugged to prevent powder entry using a finger rolled ball of flash paper. Stuff like that.
The tube would reduce capacity that much, so the case should be a chosen with this in consideration.