bp pressures

[mylo68]

hi guys  new post, this should be a good place to ask about pressures, Ive been reading a good few posts here but haven't yet come across any psi pressure ratings for muzzle-loading pistols,,i quite fancy the patriot .36 cal with 25  fffg and round ball  but am curious as to what the average  psi pressures these pistols have, any info on proof tests of any other black powder  pistols would be great,  thanks in advance,.Mylo

[Flash]

It depends on how it's contained, ignited and the quantity. The typical pressures for handgun and rifle loads are around 25,000 psi. Although I have read that early European  experiments with BP caused pressure to exceed today's smokeless powders but I don't know how.

[Will Bison]

One of the Lyman books lists pressures for quite a few guns. If memory serves right, they stopped testing when pressure hit about 25,000 CUP. My guess would be that an overall average of "reasonable" loads were in the 10-15k range. That would be for pistol, rifle and shotgun taken together.

For pistols with normal loads 10k LUP is a ballpark number.

BP if confined can reach 90k or above. Turner Kirkland (Dixie Gunworks) did an interesting test many years ago. He took a section of ML rifle barrel, filled it full of powder, put a breech plug in both ends (think pipe bomb) and set it off with a fuse. The barrel held the pressure, all the gas came back out the touch hole.

[boommer]

HI guys! Pressure on real black powder is very low in muzzle-loaders, in the black powder hand book 50 cal with a 177 gr ball and 80 grs Goex 2fis just over 6000 PSI and 32 cal with 45 gn ball  and 40 grns 2f 8000 PSI and the 45-70 with a420 gr bullet 70 grns 2f 16,400 cup pressure with PYRODEX 65 grns  same BULLET 10,100 CUP. I hope it helped !   

[mylo68]

thanks for the info guys, yeah  i was thinkin it was nearer the 10,000psi mark myself,especialy when you think of the poor steel quality antique pistols used compared with todays chromoly steel,