Conversion Question

[Walkingeagle]

Hi All,
I’ve got an Isaac Haines .50 flint with a B weight swamped Rice barrel. I am going to convert this to a percussion via 1/2” drum to match the Chambers Conversion large Siler lock. My issue is likely quite simple in that I have a white lightning vent liner which I have not yet pulled. I am assuming it is currently threaded 5/16x32. Once I pull and verify I’m correct, and as I cannot locate a matching drum thread pitch, does anyone foresee an issue with drilling/tapping to 3/8x24 pitch?
Walk

 

[user 34300]

The tap drill will clean up the 5/16x32 threads....check.

I would make a drum with 5/16x32 threads before I messed with the barrel. Not everyone can do that.

Drilling the hole for the 3/8 tap is a job for a milling machine or at least a drill press. With a new sharp bit the it will want to suck into the work and jam . Do not try this with a hand drill. Better yet make the underside of the cutting flutes on the bit closer to 90*, just a tap on the grinding wheel will do it. Once you have your tap hole made leave it clamped in the mill or drill press. Remove the bit and install a tap guide. This will insure the threads start straight. Do not try to tap it by hand unguided, you want all the treads to be good.

Honestly, I prefer flint over cap from a reliability stand point. If the switch is because flint is not reliable troubleshooting is needed. With flint you only need a rock for ignition. Caps can be hard to get.

A cap lock with a drum can be unreliable due to oil in the passage. For best possible reliability a side hammer lock with the nipple screwed in the side of the barrel is best. This is a good reason to use 1/4x28 liners.

 

[Carbon 6]

I would make a drum with 5/16x32 threads before I messed with the barrel. Not everyone can do that.

That's what i would do too.

 

[JimCunn]

"I would make a drum with 5/16x32 threads before I messed with the barrel".

That makes a LOT of sense.

 

[Walkingeagle]

Any suggestions as to how to make the drum? For those pf is without a machine shop that is.
Walk

 

[Grenadier1758]

Start a conversation (PM) with those that would make a drum and see what comes of it.

 

[Zonie]

Hi All,
I’ve got an Isaac Haines .50 flint with a B weight swamped Rice barrel. I am going to convert this to a percussion via 1/2” drum to match the Chambers Conversion large Siler lock. My issue is likely quite simple in that I have a white lightning vent liner which I have not yet pulled. I am assuming it is currently threaded 5/16x32. Once I pull and verify I’m correct, and as I cannot locate a matching drum thread pitch, does anyone foresee an issue with drilling/tapping to 3/8x24 pitch?
Walk

Drilling out the existing 5/16-32 thread with a tap drill with a letter Q (.332) tap drill for a 3/8-24 thread will work fine.
The major diameter of the existing thread is .3125. The recommended minor diameter for a 3/8-24 thread is .330-.336. The finished minor diameter of the 3/8-24 thread is .335.

For others reading this who don't know, under NO circumstances should a 5/16-32 threaded hole be retapped using a 5/16-24 tap.
Using the same diameter tap with a different number of threads on it will totally ruin the hole.

 

[user 34300]

Any suggestions as to how to make the drum? For those pf is without a machine shop that is.
Walk

You will need a lathe. Somebody in your circles of shooting friends may have a lathe and know how to use it? I would probably order a die to chase the threads I started on the lathe, ~$10. Maybe a gunsmith could make it for you? Even your track drum blank will need work. No matter what you will need to fabricate parts. Unless you have the skills and tools it may not be a DIY job.

Another big problem. Will the drum screwed into present touch hole location line up with the Siler drum cut out? Honestly, unlikely. So now you will need a blank lock plate to put the cut out in the right place. Building a lock plate involves putting all the screw holes in the right spots and tapping them properly, as well as straightening the plate and finishing it. It is not easy to get right.

This "simple" project has some serious pitfalls.

 

[Walkingeagle]

Ok. The Chambers conversion lock has arrived from Track and fits extremely well. Below are photos of the lock in place prior to the White Lightening vent removal, as well photos with the vent removed and a blank 1/2” 5/16x24 threaded drum screwed in just till it started to grab (for the sole purpose of trying to check fit and clearance). Optimum for me is to build a system that can be swapped back and fourth from flint to percussion. I believe my best option with this is to drill and re-tap as 3/8x24 with the 1/2” drum.
Walk

 

[user 34300]

You need to support the drum against bending from the hammer strike. If you don't it may fatigue and break and blow off during firing. It may shoot off at a dangerous velocity. Looks like the cut out location is very close, good. Make or have made a larger drum with the fine threads. Adjust the plate cut out to fit the drum and support it. You will want to spot it in to have as much contact as possible with the drum. Although you bought a drum, I think you really need to make one a little larger with the 5/16-32 threads. Maybe you can find an old time gunsmith who likes doing interesting projects and is willing to help you.

 

[leverfred]

Ok. The Chambers conversion lock has arrived from Track and fits extremely well. Below are photos of the lock in place prior to the White Lightening vent removal, as well photos with the vent removed and a blank 1/2” 5/16x24 threaded drum screwed in just till it started to grab (for the sole purpose of trying to check fit and clearance). Optimum for me is to build a system that can be swapped back and fourth from flint to percussion. I believe my best option with this is to drill and re-tap as 3/8x24 with the 1/2” drum.
Walk

I have a new drum that is 5/16" and I have one 3/8". Would you like me to send you one? If so, send me a PM.

 

[Walkingeagle]

I have a new drum that is 5/16" and I have one 3/8". Would you like me to send you one? If so, send me a PM.

What is the thread pitch sir? I assume neither would be 32 threads per inch. Most likely 18 or 24.
Walk

 

[leverfred]

5/16" x 24. It is easy to tap the threads different. I have done it 3 times with no failures. I recut the threads on the drum, not the barrel.

 

[Walkingeagle]

Thanks. I already have three blank 5/16x24 drums, so I will pass on your gracious offer. Very much appreciate the thought though sir.
Walk

 

[leverfred]

You are most welcome. Good luck with your project.

 

[user 34300]

5/16" x 24. It is easy to tap the threads different. I have done it 3 times with no failures. I recut the threads on the drum, not the barrel.

It sounds like you are proposing running a 5/16 x 32 die over the existing threads or running 5/16 x 24 tap in the existing liner threads???

OP, PLEASE PLEASE DO NOT DO THAT!! Zonie already warned against the idea. Why? The chased threads will be missing most of the surface area and strength. The drum has an excellent chance of bowing out. It could easily kill the shooter to your right.

Amazon sells a 5/16x32 die for $9. Buy one.

IF you must do this job without a lathe, chuck the 3/8 thread drum in an electric drill. File the threads off the the major diameter until it is correct for 5/16x32. Make new correct threads with the die you bought. Figure on botching a couple of drums before you get it right.

You really need a lathe to do it right. Any competent machinist or gunsmith can retread your 3/8 drum in a few minuets.

Be sure the flame passage in the 3/8 drum is not so large as to compromise the strength with the new 3/8 threads.

 

[user 34300]

Be sure the flame passage in the 3/8 drum is not so large as to compromise the strength with the new 3/8 threads.

Should read 5/16" threads.

 

[Walkingeagle]

Update everyone...
My parts arrived and I redrilled/tapped the barrel to accept the 3/8”x24 blank 1/2” dia drum. Everything squared up very nicely. Utilized the TOTW alignment tool to drill for the nipple then tapped 1/4”x28. Got everything cleaned up and remounted/installed. I cannot believe how well this all fit together. It really shows the quality of work that went into the original flintlock build!
Take care all.
Walk

 

[Buckskinn]

That's pretty amazing that it did all line up that well. Looks good, although I prefer a flinter...