Parker DHE 12 ga Damascus Barrels

[Ross Alvord]

Frame size is a Number 2. I'm happy it is that heavy as it could have been a lighter frame. It is a DHE or 3 Grade, 30" barrels, rib tight, barrels uncut and in excellent condition, butt stock uncut but has a Pachmayr butt pad (can I find an original somewhere, plastic or steel?, Maybe have one made if not?), bores are bright probably honed, chambers 2-1/2". This gun was sent to Turnbull for restoration work in the past, looks terrific. I'll get some pictures uploaded a bit later, just got it. At this point, I am VERY pleased with what I got in this 1905 Parker. (Gun has the date of 1905 engraved on it as I mentioned , but the serial number would say 1906 by the numbers on this website). Maybe the frame was manufactured in 1905 and serialized in 1906? What date then technically prevails? It was stated to be a 1905.

[Big Friend Ten (BFT)]

Greg,

This is mysterious and I do not completely understand the causes of detonation is a shotgun or pistol. I am not certain anyone does...

Detonation is an explosion rather than the deflagration (buring) of power. High explosives detonate via a supersonic shock wave. For low explosives such as smokeless (and black) powder, maybe under under rare circumstances a squib (far too light) powder charge may cause detonation which is otherwise known as a Secondary Explosive Effect?

Detonation may occur when using a squib load which is a serious concern when loading some light powder charge revolver ammo. I have not encountered low pressure shotgun data which produces much less than 6000 PSI in a 12 gauge. Okay, there may be a load or two at 5000 PSI but they are few and far betweeen...

To cause a detonation... If one would try to develop loads at much lower pressure than 5000 PSI they may cause a detonation which might burst or bulge a barrel at the weakest point between the chamber and the base of the wad. Perhaps a shock wave may result when the powder is mostly burned and the wad is still traveling down the barrel creating a vaccumn?

Another theory is that a reduced powder charge might be ignited too fast by the primer. If burn rate is determiend by the surface area of a powder then direct explosure of too much surface are at the energy of a primer might induce a faster burn rate? Just a theory of mine...

Where are the explosives experts when I need them?

That's my best for now...
Mark

[Carl Erickson Jr]

My suggestion is to 1: find the chamber length 2. shoot hells that have 1 ounce or less loads at a moderate velocity such as RST. I would have the gun checked out by a competent gunsmith for wood or mechanical problems to include barrel wall thickness. I would further suggest that you might want to learn how to load your own shells to meet your needs.

[StubTwist]

Mark,

What year did this chart come from DuPont? Just curious.

Frank

[Drew Hause]

"Smokeless Shotgun Powders: Their Development, Composition and Ballistic Characteristics" by Wallace H Coxe; E.I. du Pont de Nemours & Co., 1933.



Validated by Sherman Bell "Finding Out for Myself, Part VI, Smokeless vs Black", in The Double Gun Journal - Summer 2002, p.19

[charlie cleveland]

that 6 frame must be a 8 ga with that barrel weight of 8 lb 10 ounce...could be a ten ga but not many tens built with that much barrel weight..thow i think thomas s 10 ga barrels weigh over 9 lbs...lordy i like the monster guns...sorry i got off track... charlie

[Big Friend Ten (BFT)]

For Greg's question of what causes "detonation" in a barrel:

From a US Army Technical Manual:

b. Deflagration. If a particle of an explosive reaches a temperature at which the rate of decomposition becomes significant, deflagration or spattering of the particles from the surface occur prior to decomposition. At a characteristic temperature, heat output is sufficient for the reaction to proceed and be accelerated without input of heat from another source. At this temperature, called the ignition temperature, deflagration, a surface phenomenon, begins. Gaseous reaction products flow away from the unreacted material below the surface. Deflagration of all the particles in a mass of finely divided explosive occurs almost simultaneously. In a confined space, pressure increases, which, in turn has the effect of increasing the rate of reaction and temperature. The final effect of deflagration under confinement is explosion, which may be violent deflagration or even detonation. In the case of low explosives, such as loose black powder and pyrotechnic compositions, only violent deflagration can take place. Nitrocellulose propellants (smokeless powders) can burn, or if confinement is sufficient, deflagrate so rapidly as to detonate.