Hello all,

I have a 0.45 Philadelphia derringer, with a 3" barrel. I"m looking for the most potent load. With longer barrels, the heavier the load, the faster the bullet. Simple.

However, in this short barrel, the powder thakes a significant part of the barrel length. So heavier load means shorter barrel.

Can you provide info or ideas on getting the best load?
Also - what about using 4Fg instead the regular 3Fg?

I dont have access to chronograph, so cant simply experiment.

One more: how do I measure barrel length? is it the Inside bore length? The total outside length? other?

Thanks,

Try 30 grains of 4FFFF. The measurement would be inside except for the commercial people who do any way the feel like.

I may be wrong here, but I wouldn't even consider using 4F for a main charge. So far as I know it's intended strictly for priming a flintlock.

4F is a very fine powder and i also thought it was for priming a flintlock.

Ditto on the 4F...don't use it. And I would probably only use 15-20 gr of 3F. Most potent load? You're not going to get any appreciable accuracy with that lil' feller so why waste any more powder than necessary. Has anyone beside me ever wondered what charge J.W. Booth had in the barrel of the one he killed Lincoln with?

BPS

Once sure of the amount of powder that the pistol can SAFELY shoot. And I stress SAFELY as the weapon design is often based on the capabilities of the powder it is meant to shoot... I can not see something with that short of a barrel shooting any large amount of powder.

But to obtain the top performance, if percussion cap, I would shoot 3f Triple Seven powder. If flintlock I would shoot 3f Swiss black powder. Remember these were belly guns. Made to be used at extremely close quarters. Most of them only produced around 450 ft per second ballistics as I once read.

A friend of mine once owned a derringer, very much as you described. I will not say I recall the load he used. But the powder amount was very low. What amazed me was the penetration of that ball at close ranges when he shot it. He shot into bundled magazines. And I never thought it would penetrate as deep as it did.

BPS...If memory is correct the one used to kill Lincoln was about .40 caliber, I can't imagine Booth using more than 30-40grs...

I've also read that Lincoln also probably died as much from one of the doctors probing for the ball as the damage made...

To the OP, I'd start with 20grs FFF Goex and move to about 40grs...You can check penetration by shooting into gallon jugs of water or 2x4s...

I would probably only shoot no more than 20 -25 gr of FFFg. With its 3" barrels you're likely not to get much accuracy past 10 or 15 yds anyway. Which is all this little guy was intended for (and probably much closer.)

It's just a Belly Gun. You stick it in someones belly and pull the trigger. Here is a target shot with mine at 3 feet away using 15 grains of 3f Goex and olive oil for a patch lube. Have fun with it and be careful.

That's good shooting. And your right... close range, big hole. I would think the worst would be that ball bouncing around in your innards.