Parker DHE 12 ga Damascus Barrels

[Big Friend Ten (BFT)]

The Dupont pressure curve chart posted by Greg shows that as the wad and shot are pushed down the barrel the pressure is on a constant rate of decline. Key points of this are:

1. A load which creates excessive pressure will burst or bulge (cause permanent deformation) the area at or very close to the chamber.

2. A barrel that burst or split much past the chamber had an obstruction in it which caused a rapid rise in pressure. Since the wad and shot were far from the chamber the thinnest portion of pressure vessel (barrel between the breach and base of the wad) suffered deformation.

3. A very low pressure load can cause detonation which can damage a barrel. This is different than too high pressure caused by an overload or obstruction in #1 and #2 above.

[Wild Skies]

Originally Posted by Mark Ouellette

3. A very low pressure load can cause detonation which can damage a barrel. This is different than too high pressure caused by an overload or obstruction in #1 and #2 above.

Mark, would you please explain this? What would be considered a very low pressure load in terms of psi?

[Wild Skies]

Originally Posted by Mark Ouellette

3. A very low pressure load can cause detonation which can damage a barrel. This is different than too high pressure caused by an overload or obstruction in #1 and #2 above.

Mark, thanks for posting that from the US Army Technical Manual. I still wonder if a very low pressure load can cause detonation which can damage a barrel. Hopefully the published low pressure 7/8 and 1 ounce recipes utilizing PB powder that generate 4300 to 5100 psi that I'm using in my damascus guns aren't adding any additional risk.