Low pressure for hammer gun
 

I was wondering if there is a big if any pressure difference between 2" and 2
1/2 " shot shells for a 12 gauge hammer gun. I acquired an 1880s #2 grade and proofed it to with 2" game bore 1 oz rolled shells. I want to go low pressure and will let the gun lay until my Manson WTG arrives.
I want to go soft on this gun. RST still lists both 2" and 2 1/2 " loads and I was wondering with the same shot weight whether one would throw less PSI than the other. I don't assume that that 2" is less because the hull is shorter. It could in fact be a little hotter.? Could not get RST on the phone
Thanks

Curious - how did you proof it with a factory load? or do you mean test fired?

RST would be the best best for info, keep trying- they have always responded to any voice mail I have left.

but since both lengths in RST are meant for vintage guns, I would not expect a significant difference.



PS;

pictures?????

[QUOTE=Rick Losey;139720]Curious - how did you proof it with a factory load? or do you mean test fired?

Poor choice of words on my part - yes test fired.
I'll send pics soon can't do it from the ipad

Here are some pictures. hope they come through.

Great gun Eric! Congratulations

very nice Eric - looks like its in great shape

Low Pressure Ammo
 

Eric, I am not an expert, but I would expect a 2" shell using the same design of hull, wad and crimp types throwing the same shot charge weight at the same velocity will have a significantly higher pressure (say 15 % or more) than the same load in a 2 1/2" hull. I believe the lowest pressure 12 gauge load RST offers is their 2 1/2 "Falcon Ultra Lite" 3/4 oz. shell at around 4500 psi. Their 2" load is listed at the same velocity of 1125 fps but uses a heavier 7/8 oz of shot. Alex, Jill and Morris are always great people to deal with and would definitely be worth calling at RST for more information. I hope they are able to get a shipment of powder and get back on line loading again soon. HTH.

Eric what a great gun and congrats on your new adoption. I just shot a recently adopted grade 1 from 1880 myself. I have two #2 frame 12ga hammer guns and load the 2 1/2 inch RST hull using International Clays with either 1oz or 7/8oz of shot. Low pressure and low recoil and 1100 FPS.

Or you can do what Parker said. From the 1882 catalog, 1 1/8 oz at up to 4 drams, certainly a stout load.

Fred, what evidence or experience do you have to suggest a shorter length hull will produce more pressure than a longer hull with the same primer, amount of powder, wad and shot weight? What would cause the pressure to increase when each is fired in a gun with the proper chamber size or longer chamber size? I don't see the physics that would cause that to happen.