But a buddy of mine, a real gunsmith, thinks about what-if games, like what if I run out of percussion caps but I still want to shoot my favorite muzzle loading rifle?

The answer nobody asked for, but it's really cool. Got to fire it too - the time from pow to bang is VERY short.

That’s clever
I thought about this first

He does that already,  and makes his own black powder as well.

The tap a cap works
There are drawings on the internet so you could make one ( easy if you have a metal lathe)
Sheet copper from hobby lobby works better than soda cans
I understand German made cap gun caps are the best to use to put the primer material in them with
I have thought making a custom nipple for the red ring caps would be good for practice shooting

We did toy caps as well. Testing is still in the works, just haven't had time.

When I tested toy gun caps in my youth, I never had problems igniting any BP loads, but they are full of corrosive salts, so if you do use them in any capacity, just make sure to clean everything thoroughly.

The newer ones are much weaker than the old ones. We always clean thoroughly.

Nothing new under the sun...  That process in reverse converted thousands of flintlocks to percussion in the 1800's and shooters are still doing it today.

I'm happy the guy is pleased with himself ....

Thank you for your comment, however you missed the point. It's a convertible,  not a one time deal, can go back and forth in a few minutes. He should  be pleased with excellent work. What have you done?

Nope, didn't miss the point.  Dixie Gun Works sold parts to convert rifles they sold back and forth in the 1980`s

They stopped because it's not necessarily the best idea as every time you switch you cause wear on the threads.  The percussion lock has to be perfectly fitted against the drum to support it.  If not,  every hammer strike will cause a minute amount of metal fatigue and eventually crack the drum off.  This isn't an issue with a snail,  which is why you don't see any commercially manufactured  percussion rifles with drums.

I started building muzzleloaders from scratch in the 1990's and have completed over 30 flintlock, percussion and mule-ear rifles, pistols, and fowlers.

That is wonderful and you should be very pleased with yourself. All kits?

I said from scratch.
No kits or pre carved stocks.  A barrel, a plank, a lock and rough cast butt plate and trigger guard.  All other parts hand made.

Oh, OK, like when he made this one? He had a barrel stub left over after saving my son's rifle from Bubba, and a few locks to play with, so for grins and giggles he built this for fun. I liked it so much I bought it from him for my son. He made the trigger guard, nose cap, sights, (that rear sight was a single block of steel), ramrod, the whole thing, just as a rough cut lark. This was just a way to kill time.





But it was sister to another he built the same way, again, same time, just a barrel and a lock. The curved grip was odd, but comfortable.



The earlier trigger guard - it was not comfortable, so he made his own.



Some more making of pictures.







Front sight.


These are the parts he started off with to make both pistols. The one I have is .54 caliber - I think the other is .50.



And the stocks are made from this block of wood from his mesquite tree in the back yard.



LAGS started making black powder firearms by hand when I was a babe in short pants, and I am closer to 60 than 50. I think you two should talk - he loves getting new and different perspectives from other people who can do this kind of work, and swapping tips/tricks/ideas/etc. You can find him over at castboolits, very nice guy. I have a HUGE thread over there about when he salvaged Da Boys rifle, too.
Would love to see one of your home growns!