doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Thin barrels passing London proof

Larry;
Agreed; read this line from my last post "The pressure there will in fact be very sightly higher, though mostly insignificant". This is what I have been saying for ages. People though still keep saying I have barrels which are thin in the forward end, therefore I am going to shoot "Low Pressure" loads to protect them. They are simply like an ostrich with their heads stuck in the sand. True the difference is very slight, but whatever difference there is, it is in the opposite direction of their stated goal. Nuff said, you either have it by now or you'r one of the Ostriches.

Another pressure curve to demonstrate Miller's point
�Powder Pressures At Different Parts of the Gunbarrel�, 1895
https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA32&dq

The choice of 32 grains of Ballistite is confusing, as 25.5 grains is the published load for a 3 Dram equivalent.
According to https://books.google.com/books?id=inQCAAAAYAAJ&pg=PA7
this is the Dram Equivalent for the grains listed for the Nitro Powders:
Ballistite 32 gr. = 3 3/4 Dr Eq.
Walsrode 34 gr. = 3 1/8 Dr Eq.
Cannonite 38 gr. = 3 1/8 Dr Eq.
Schultze 42 gr. = 3 Dr. Eq.



All 4 curves meet at 6" but at 12" the pressure for Dense Ballisite is 1600 psi by Burrard's conversion; Bulk "Schultze" 1900 psi. The difference continues out to 24". Of course no "progressive burning" powder was available in 1895.