Underhammer Flintlock

[Kermit]

Sorta destroys the question of where in the pan the prime charge should rest. Certainly can't bank it against the touch hole!

[Larry Pletcher]

Brent,
Null B is priming powder mades by Swiss.  Thay also make a 4fg priming powder.  In timing experiments, Null b is the fastest prime we have, followed in order by Swiss 4fg, Goex 4fg, 3fg, 2fg, 1fg, cannon, etc.  (I hope to get at a comparison test of Null B and some 7fg that "Frizzen"  (list member) gave me.)

I suspect you're right about a sawdust box.  There is considerable set up involved in getting a pic of a paper patch separating.  I won't say I can't do it,  but it's  tougher than a cloth patch.  With help I think I could repeat the cloth patch pic in a good afternoon.   With paper patch there is some trial and error work to do  that has already done with cloth.

Metalshaper,
 The cannon pieces that fell to the table are those that were released first by the frizzen or that were not impeaded by the frizzen.  In some cases the ball of fire expands and burns some of them.  In timing tests, Goex cannon is roughly twice as slow as Null B.  If lock ignitions are within the normal .0400 - .0500 second range it won't matter what priming you use up-side-down.  But, my gut says that you don't want to use 2fg or larger.

Sorta destroys the question of where in the pan the prime charge should rest. Certainly can't bank it against the touch hole!

Oh , but I do.  Against the vent is 15-25% faster than banked away.  I haven't timed up-side-down vents though, but the closer the prime is to the vent the faster the barrel ignition.  I have a web page on that too.

Regards,
Pletch

[Acer Saccharum]

Catching a paper patched bullet in your garage would not be too difficult with a sawdust box.

Larry, just in case the sawdust doesn't completely stop the bullet, I'd park the Double A off to the side.

[Acer Saccharum]

Now, on to vent location for an underhammer.....

Do you put the vent as high as you can go? That would make it at the bottom of the pan if you turn the gun upside down.

Or mid-pan, or even a little lower, as to be obscured by the frizzen edge?

[BrentD]

Catching a paper patched bullet in your garage would not be too difficult with a sawdust box.

Larry, just in case the sawdust doesn't completely stop the bullet, I'd park the Double A off to the side.

8 ft of oiled sawdust will stop a 550 gr bullet launched at over 1400 fps.  Every time.

[D. Taylor Sapergia]

That reminds me of the time I wanted to test for pressure signs in my Sharps 45 x 3 1/4".  With a full case of powder and a 500 full jacketed Hornady bullet, I knew I needed something to stop the bullet, but I thought the twenty-four inch diameter spruce stump on which my anvil sits would do the trick.  After all, a round ball only goes in a couple of inches.  So, when the house was empty, I put on my ear muffs, stepped back about ten feet from the stump, aimed at the middle and touched it off.  The concussion cleared the rafters of twenty years worth of shop dust, but there was considerable more dust in the air than I thought reasonable.  The bullet completely penetrated the stump, exploded a new ten pound bag of kitty litter, and stopped on the far side of an eight inch square timber in the corner of the shop that just happened to be in the path.  Apart from the rifling marks on the bullet, there was no other damage.  And, no signs of excessive pressure.  Now I could see why I never recovered the bullet from a moose.

[Larry Pletcher]

Since we are pretty far from underhammer flintlocks,  I will move my paper patch bullet photo reply to "Black Powder Shooting".

Regards,
Pletch

[Larry Pletcher]

Bookie,
One of the under hammer flint photos I found was included in Metalshaper's post.  Here is one that shows a neat pistol but may not show enough of the action to be useful.  



Regards,
Pletch

[Steve Bookout]

Gentlemen, I thank you for the photos.  That last pistol is certainly a work of art to me.  Altogether, they do give me some idea on which way to travel with this project.  Several times, I have fired Siler flints upside down after priming, cocking, putting my thumb over the notch in the pan for the vent, and then drenching it under a running faucet to convince customers that a well tuned and properly maintained flinter is just as reliable as percussion.  So the pan emptying too soon was not one of my concerns at all.  I have seen the in line flinter made in the 1760s, but that is something beyond my metal fabricating skills and personal interests.  Brother Dan hits the nail on the head with me, because I like to fool with the unusual, most probably to feed my ego by telling myself 'I did it'.    Now I gotta go find me that book.........Cheers, Bookie

[Jim Kibler]

Bookie,
One of the under hammer flint photos I found was included in Metalshaper's post.  Here is one that shows a neat pistol but may not show enough of the action to be useful.  



Regards,
Pletch

Seems this is pretty much a standard box lock design turned upside down.

[Steve Bookout]

I agree with you, Jim.  Cheers, Bookie

[Acer Saccharum]

It's pretty hard to see the sights on a standard boxlock, unless you have a scope mounted on the side.

[John Ciccone]

I was at friendship in Spring of 2017. A guy showed me his underhammer flint pistol. He said that Null B was too fine and tended to be too easily dispersed by the breeze, but 4FFFF worked just fine. He refused to sell the gun to me. Ok, I' m a bit crazy, but so is everyone else on this list...delightfully so.

[Mike Brooks]

Groove yard of forgotten posts..... NOT a sidelock....just thought I'd mentioned that.

[Dennis Glazener]

Yes Mike I was about to post this and was told there was a new reply.

Ok guys this was a 7 yr old topic that pre-dates our side lock only rules. I am going to lock this to keep it from being revived.
Dennis