I would not use the Rocky Mountain Brass. It is turned (not extruded) and would use a 12 gauge wad instead of an 11 gauge wad. Many of the older guns had larger bores, not the now standard .729. I have one that has .751 bores. The 2 1/2" extruded brass by Magtech (CBC) will hold, as I remember a stiff load of BP and shot. You just need to cut back on the wadding. Ask Craig Smith owner of Circle Fly Wads. He often uses less wads and he has done extensive BP shooting both muzzel and breech loader.

Harry

Paul, I got a message from Craig at Circle Fly. Based on what he said, I am thinking that the Goex load of 3 3/4 or so drams is about all you could fit. I will start lighter and work my way up to see what works.

Harry,

What is the problem with using turned, rather than extruded brass? When I get the gun back from the gunsmith (you know how long that can take) I'll check the bore diameter. I have 3 Parker GHs (1896,1903 and 1907) all bores are .729, but I have an 1889 Remington that is .724, so I can see what you mean about the bores.

Paul B.

Paul,

A difference of .005" should not matter much to the wad sealing or pressure developed. A difference of a .022" larger bore as Harry mentioned would likely have a negative affect on a fiber wad sealing.

The above stated, I use Gauge Mate adapters to shoot 12 gauge in 10 gauge guns. the plastic wads which I use, normally Claybuster brand, seem to seal good enough. I am using smokeless powder which because of a longer buring time may allow the under-sized wad time to seal in the larger bore. One of you black powder guys please correct me if I'm wrong on this.

Mark

For what its worth...
Mark

Paul,

Like Mark, I too shoot 12 gauge plastic shells and wads through my 10 gauge guns with great success. When I shoot BP in the 12 and 20 gauges I use extruded brass and a fiber wad one gauge larger. I did have some 10 gauge Ballard Brass (now produced by Rocky Mountain) and shot 10 gauge .790 wads through .802 bores. I just thought that if I had extruded 10 gauge brass that used 9 gauge .815 wads I would have gotten a better seal. The Rocky Mountain brass may work wonderfully for you, but you can purchase 25 Magtech 12 gauge shells for $22.49 where 25 Rocky Mountain 2 7/8" 12 guage brass hulls will cost $170.00.

Harry