Watch That Powder!!!!

[Lars]

Hello Folks!!

I am posting this here because NCOWS has many shooters that use both BP and nitro loads, as well as many old guns. The thread cited is from the Double Gun BBS and describes and "accident" waiting to happen, one that could have happened to lots of folks. It also illustrates just how strong quality old Damascus doubles can be/are. The link is ... http://gunshop.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=021885

Lars

[Silver_Rings]

Lars, that's pretty amazing that the gun held up so well.  Would have expected a lot more catastrophic failure of any shotgun.

SR

[Lars]

Here is link to picture of damaged Remington hammer double.
http://gunshop.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=021924

Note that this barrel ruptured much like one would expect from a fluid steel barrel. NONE of the "unwinding like a slinky" nonsense that is so often bantered about by folks that never saw a good quality Damascus barrel that ruptured.

Yea verily, Silver Rings!! How many guns out there could taked a 3-fold overload and not rupture?? FYI, some years back a Parker with Damascus barrels was subjected to increasinly higher proof loads until it finally ruptred a over 30.000 psi -- and only then where the extracter cuts were. I would never claim such strength for a cheap hardware store double with low quality Damascus, low quality twist, or any fluid steel barrels.

Lars

[Lars]

Here is a quote from a member of the Double Gun BBS about this accident.

"This seems to be an example of the "smokeless for bulk" accidents that were reported as blackpowder was being replaced."

SO, go look at the second thread about this accident and see not one but two pictures of old Damascus doubles with chambers blown out. Kinda gives us a peek back into some late 1890s early 1900s sorts of events that must have been all too common as the early nitro powders came on the market, especially when the nitro powders went from bulk powders to the less bulky, more modern nitro powders.

Lars

[Lars]

Here is a bit more precise explanation of the chamber pressures involved in this accident. This is from the Double Gun BBS and is in response to question from a non-reloading shooter that does not know one powder from another.

" Paul intended to load black powder in his shells. A charge of around 74 grains (about 1/6 ounce) would have produced near 7000 psi in the breech of the barrel. There is a nitro base powder named PB that is often used in shotshells, especially to make lighter loads with low pressure. PB looks a lot like black powder on casual inspection. However, the energy content of the PB is such that a charge of around 20 grains (1/22 ounce) will produce a load similar to the black powder. Having mistaken the identity of the PB for black powder, the shells were loaded with a weighed charge of 74 grains, a 3.7 times overload. This overload of powder produced a breech pressure that was probably in excess of 30,000 psi, about 4 times over what was intended. That the gun burst is no surprise. That it endured three with bursting is a surprise."

Lars

[Ottawa Creek Bill]

Lars,
Excellent post and a warning to those of us that load black powder to be that little extra cautous and not mix powders, especailly those of us that shoot antique doubles. You can ruin a nice old gun, possibly lose a finger or two, maybe a hand, and maybe even your or a shooting companions life....

Bill

[Delmonico]

The way it blew does not surprise me, that is the way I would expect a properly welded Damascus barrel to go.

I did see a "cheap" Damascus barrel that unwound on the inside of the barrel.  This of course was a barrel that I'm sure did not get heated hot enough when forged and did not get full penatration on the welds.  The fella who shot it was under the impression is was one of the solid steel faked twist barrels.  He did check the bore before firing the next load which was a standard 1980's AA Trap load.

As a note SR7625 has some even lower pressure Nitro loads than PB, I've used these loads before with modern guns for pattern improvement.  However these Nitro loads with the older powders that generate these lower pressures may not be safe to use in extreme cold.  I learned that one day when I shot 1 oz of copper #4's on a -15 day and watched the shot almost roll out of the barrel on every round.

[Lars]

As a note SR7625 has some even lower pressure Nitro loads than PB, I've used these loads before with modern guns for pattern improvement.  However these Nitro loads with the older powders that generate these lower pressures may not be safe to use in extreme cold.  I learned that one day when I shot 1 oz of copper #4's on a -15 day and watched the shot almost roll out of the barrel on every round.

Del,

All too many folks have had just that experience with low pressure IMR SR7625 loads in cold weather. I am a big fan of that powder for the really nice, even patterns I get, but, for cold weather hunting I ONLY load for about 9.500-10.500 psi at warm temperatures, use Federal 209A primers and a wad that allows no powder migration in that hull. Over about a quarter century of using such loads in 12 and 16 gauge I have NEVER had a blooper or even a shot that sounded weak, even down to below 10F. Even at low tempertures these loads burn quite clean.

Downloaded IMR PB is said to not have the extreme temperature sensitivity of underloaded IMR SR7625 (about 7.000 psi at warm temperatures) but, I have never put it to the test.

Lars

[Delmonico]

PB was the one I had trouble with, but it was -15.  Used to use 1 oz of copper plated #4's for bunnies on the snow, shot went clean through and didn't draw hair in.

[Lars]

Used Cu-plated #6, #5 and #4 high Sb shot for decades because it did not draw much fur or feathers into the critter. Always thought that lack of drawn in fur and feathers was the main factor in the much better penetration. FYI, I now see much the same behavior with Bi-Sn alloy shot on ducks and geese.

Don't recall ever shooting anything at -15F!!!

Lars