Should the powder charge be equivalent to the caliber?

[Khufu]

Do you still have the Philadelphia Derringer? It would be interesting to see velocity numbers for different loads in the Philadelphia Derringer.

I do, and I will Chrono it next range trip, but I am pretty sure it is pretty slow there is not a lot of barrel there.
even with 20 gr of 4f, I doubt it will get close to 300 fps. but it would be interesting to see.

 

[stephenprops1]

I'd start filing that rear sight down as soon as I found a accurate load.

Wouldn't that just make it shoot higher? The rear sight is adjusted the opposite of how you want to move the point of impact. The front sight is adjusted the same as where you want to move the POI. So, I would either file down the FRONT sight or build up the Rear sight. Right?

 

[Khufu]

Wouldn't that just make it shoot higher? The rear sight is adjusted the opposite of how you want to move the point of impact. The front sight is adjusted the same as where you want to move the POI. So, I would either file down the FRONT sight or build up the Rear sight. Right?

you have that exactly backward, raising the front sight makes it shoot lower, raising the rear sight makes it shoot higher.

 

[cal.45]

I do, and I will Chrono it next range trip, but I am pretty sure it is pretty slow there is not a lot of barrel there.
even with 20 gr of 4f, I doubt it will get close to 300 fps. but it would be interesting to see.

View attachment 133307

Great! Looking forward to see the numbers. Found this video, from 9:00 in the video he shoot watermelons with a Philadelphia Derringer. A 15 grain load did penetrate the water melon all way through, but 30 grains blew it up. I also found this test Educational Zone #66 - Shooting a Black Powder Pistol - The Box O' Truth with 30 grains the Philadelphia Derringer penetrate only one jug of water, but with 40 grains it surprisingly penetrated four jugs. So heavier loads seem to increase the velocity in the Derringer despite the barrel being short.

 

[Khufu]

Great! Looking forward to see the numbers. with 30 grains the Philadelphia Derringer penetrate only one jug of water, but with 40 grains it surprisingly penetrated four jugs. So heavier loads seem to increase the velocity in the Derringer despite the barrel being short.

to be honest, I have never loaded it up above 20 gr of 4f, the only thing I ever really used it for was carrying it in places with no firearms signs.
I loaded it up to the point where it seemed potent enough to slow someone down enough that I could escape with my hide intact. At 20 gr the ball seemed awfully close to the muzzle. but its worth a try to see just how potent I can get it, I did load a try .45 minnis but that was way too much of a jolt and it seemed to be a lot slower. basically these things are only good for very close range injection. I am a decent shot, and at 25 yards I could not keep them on the paper, and a lot missed the entire man sized target. since I moved to New Mexico, where the law says they are a firearm there has been no need to carry it and its relegated to wall hanger status.

 

[shorthair]

That's a rule of thumb for a rifle starting load, not pistol. I don't think even a Ruger Old Army or Walker could hold 44gr!

While I do not recommend nor advise this my old hunting partner loaded his ROA with Pyrodex p by filling each chamber to the top then ramming and refilling twice more before seating the ball and covering with lube. He did this for several years but I don't know how much powder it held with his method, but it did shoot very fine 50 yard groups.

 

[stephenprops1]

you have that exactly backward, raising the front sight makes it shoot lower, raising the rear sight makes it shoot higher.

OK. I stand corrected. That's why I have this written down in my gear box, so I check my notes before making any adjustments. Thank you for telling me this, even if I am a little embarrassed.

 

[cw1873]

20 grains and significant recoil, 45 grains and mild recoil. How come pistols differ in recoil like that? Is it only a matter of the weight of the gun? What’s the weight of your guns?

There has to be something else going on there. 45 grains of powder is a lot of energy. I put a 50 cal pistol across a chrono and I'm over 1,000 fps with a 0.490 ball with 40 grains of FFFg. Maybe a difference of looser ball/patch combo in one?

 

[Loyalist Dave]

That's a rule of thumb for a rifle starting load, not pistol. I don't think even a Ruger Old Army or Walker could hold 44gr!

Correct that's an old rule of thumb for rifles, and you round up to the nearest five or zero, so a .50 would use 50 grains, but a .54 would use 55 grains.

LD