8 bore bp loads

[¡Señor.Casualidad!]

Slightly off topic. I could never understand how the pin fire hull could seal gas escape. Your pics clearly show zero detectable gas leakage. Impressive.

Oh its there. Albeit pretty minor

 

[Daryl S]

That tiny puff of gasses of interesting. I'd have thought a LOT more would show in a bore rifle.
Late friend and buddy, Leatherbelly shooting a .50 Beck longrifle with vent smaller than 1/16".
I had figured likely 1/2 that at each shot from a pin fire. Obliviously not.

 

[Kynoch2015]

Still impressive!

 

[Daryl S]

VERY!

 

[Kynoch2015]

Not sure on that @Daryl S don’t forget my 3in 15lb 12bore rifle !

No reference to case length, but reference to 9 dram loads (Double Gun Journal, Fall 2002). Have one on the other end of the spectrum at 2 drams. At 9 drams, I think I’d just step up to an 8 bore

 

[Daryl S]

Interesting. The 8 dram load is listed for round ball, while the new 9 dram load is listed with both round ball at 600gr. and slugs at 750gr. 750gr.
Greeners book lists only 4 1/4, 5 and 7drams, all with round balls.

 

[¡Señor.Casualidad!]

Given the weight of the gun and the fast twist, any chance that this was intended for lower velocities? A way to stabilize low velocity bullets is to use a faster than normal twist as they do in the various subsonic loads/calibers. Just a thought. Regardless, really cool gun!

Muzzle velocity would need to stay under 1100fps to keep the recoil energy under 200ft lbs

 

[Daryl S]

In the mid 1800's, some English makers had some weird ideas abut rates of twist, but I've never heard of one that fast. Forsyth wrote in 1860 of a 13 bore double(muzzleloading) he had, that had a 24" ROT and would not shoot accurately with anything over 1 1/2 drams of powder. Round ball of course.