ARmy Rumour SErvice

Although I'm a devout follower of the 'no air gap in bp loads' doctrine...I do know at least one very good shooter who has a gap in his .577-450 loads. He never has had problems as far as I know. But of course there's an air gap and an air gap...he'd not talking an half empty case.

I've also read over the web about the commercial BP ammo loaded for various old cartridges whick by all accounts rattle when shaken. Now if they dare sell those in the US o fA with it's law suits for everything culture...then I guess a small air gap isn't as explosive as we all tend to believe.

I'm still not going to try it though just to find out.

There are no absolutes in black powder shooting...that's what I was told when I first started out and it certainly would appear to be true.



Whilst we're charcoal burning, here's the other-half's Alexander~Henry .451 front stuffer.

Originally Posted by Munter Hunter

Whilst we're charcoal burning, here's the other-half's Alexander~Henry .451 front stuffer.

..................I'm just going to go and lie down on my bed for a bit. with that pic. and the door closed.

I can save you the trouble Doc...it's not a real one but it has been mistaken for one before.

Originally Posted by Munter Hunter

I can save you the trouble Doc...it's not a real one but it has been mistaken for one before.

What do you define as "real"? If the rifle is in fact a 1:1 repro then the only difference is who made it and when.

Some companies make true copies while others make guns with minor or major changes due to safety or manufacturing constraints. It is quite tricky if you really are looking for a true reproduction.

Originally Posted by Croque_Monsieur

What do you define as "real"? If the rifle is in fact a 1:1 repro then the only difference is who made it and when.

I define real...in the sense I used it, as a rifle being made by the man himself...and therefore the 'real' thing, not a recent reproduction no matter how exacting.

its real enough for me ;)

Me too...but without the ten grand price tag or whatever it is an original would run at thesedays.

I did some trials a few years back with copper tubing after reading an article about ringing, and I can confirm the effect..

The trial consisted of firing (electrically) small GP charges in copper tubing (simulating a barrel) with a lead ball at varying air gaps.. It "rings" almost every time if the ball is not seated on the charge. I only had a limited time (and tubing) so I only did about four of these these trials.

I think the effect is caused by shock wave reverberation - I will try to do some more if I get the chance.

Gunpowder behaves in a significantly different way to nitro powder. Nitro powders are rubbery solids and the burning is very much a surface effect, with the burning rate very dependent on pressure. In other words, the larger the surface area, and the higher the chamber pressure, the faster the burn rate.

Gunpowder has a much more frangible structure. The mealed grains are very hard, however the basic structure of the mix is very fine. The burn rate is slightly affected by the grain structure and the pressure, but not nearly to the same degree as nitro. The problem with gunpowder was to slow down the burn rate, so as not to burst the gun. This is why cannon of the 1890s was short and fat. Attempts were made to slow down the burn rate by using partly charred straw instead of charcoal and by moulding the powder into large "prisms" but it was never that successful.

Cordite, on the other hand was extremely controllable simply by adjusting the grain size. By changing the size and shape you could use essentially the same propellent in both .303s and 16" naval cannon.