Chamber Pressures

[Big D]

Seems to me that velocity is overrated.

Allow me a few simplifying assumptions:
Bird is flying across at 30 mph at 30 yards
Two different loads - 1200 fps and 1400 fps. For simplicity, I will assume the average speed of the shot over the travel to the bird is 900 fps and 1050.

The difference in the movement of the bird between the two loads is about 3".

[Bruce Day]

Originally Posted by John Dallas

Seems to me that velocity is overrated.

Allow me a few simplifying assumptions:
Bird is flying across at 30 mph at 30 yards
Two different loads - 1200 fps and 1400 fps. For simplicity, I will assume the average speed of the shot over the travel to the bird is 900 fps and 1050.

The difference in the movement of the bird between the two loads is about 3".

You are preaching to the choir. And absolutely correct. But it allows a manufacturer to sell a customer on his annual pheasant hunt , at Cabelas in Mitchell South Dakota , a box of 1 1/4 oz 5's at 1400 fps for $15 instead of a box of 1 1/8 oz 6's at 1180 for $8. And if I keep on missing , it must be because I need more powerful shells.

[Drew Hause]

"Bulk smokeless is measure in drams same as black, dense smokeless in drams equivalent black."

Indeed, and the reason for many of the damascus bursts

Sporting Life Sept. 10, 1904
“Burst Gun Barrels”
http://library.la84.org/SportsLibrar.../SL4326021.pdf
The number of burst gun-barrels which, comes to the attention of the shooting public is remarkably small, considering the thousands of guns in use throughout the country. The main reason for the comparatively small number of guns burst is the great use of factory-loaded shells, or the hand-loaded of reliable dealers. The day of loading one’s own shells is pretty well passed, therefore, the over-loaded or double-charged cartridge is very seldom found. Very often a burst barrel is blamed on the gunmaker or the shell-maker, but more often on the manufacturer of the powder. Cases are known where a party blowing out a gun-barrel, using an extra heavy charge of dense powder, blamed it on a bulk powder. A suit for damages was quickly withdrawn after an examination of the gun had been made.

1907 Sears, Roebuck & Co. Catalogue No. 116 courtesy of Gary Rennles

“Nitro powder should only be used by people familiar with it; and dense nitro powder should be weighed by an apothecary’s scale and not measured.”



A 3 Dr. Eq. (Dram Equivalent) load of “E.C.” No. 1 or “Schultze” was 42 grains by weight. 3 Dr. Eq. of Dense Smokeless Ballistite was 24 grains; Infallible 21 grains. The pressure of a 3 Dram (82 grains by volume) load of Black Powder propelling 1 1/8 oz. of shot at 1200 fps is about 5000 psi. The pressure of 1 1/8 oz. 3 Dr. Eq. of BULK Smokeless was 6500 - 7500 psi; 3 Dr. Eq. of DENSE Smokeless was 9000 - 10,000 psi.

Substituting a Dense Smokeless powder for Black or Bulk Smokeless powder would double the charge. It has been estimated that 50 grains of Infallible or Unique could reach 30,000 psi. Combine this error with a 3” shell in a 2 5/8” or 2 1/2” chamber, and a barrel rupture might occur in any barrel, fluid steel or Pattern Welded.

[Drew Hause]

1902 Sears catalog No. 112

"Gun and rifle barrels can only burst by having some obstruction in the barrel or by overloading with Nitro powder."



THE PARKER GUNS: ALL ARE BORED FOR NITRO OR BLACK POWDER