Indexing drum

[Nuthatch]

I'm converting a Pedersoli Kentucky to percussion. The lock & drum assembly are on order. One person had mentioned that there's a threaded tap available from TOTW to help index the nipple to the hammer. But this drum from DGW is already fitted with a nipple. The rep at DGW said that indexing is done by removing material from the threaded end of the drum to adjust where the threads begin to bite in.

For those of you who have done something like this, what is the best way to remove this material? My first thought is to test fit & then clamp the drum in some vice grips & gently grind off material with a bench grinder on the side of the stone to keep it as square as I can, testing frequently. But I'm no gunsmith so I'll take the advice of those who know better.

Also, how tight does the drum need to be once installed?

 

[2 shots]

i think a lathe would be best. tracks drum blank would be easier if you dont have access to one. cant see being able to put it anywhere near a grinder without taking out the threads . look closely at a drum. with a blank you can put the nipple where needed. also have to keep track of the barrel wall thickness. does that gun have a pattern breech? snugged up nothing crazy.

 

[Nuthatch]

i think a lathe would be best. tracks drum blank would be easier if you dont have access to one. cant see being able to put it anywhere near a grinder without taking out the threads . look closely at a drum. with a blank you can put the nipple where needed. also have to keep track of the barrel wall thickness. does that gun have a pattern breech? snugged up nothing crazy.

Yes -- Pedersoli patent breech

I think taking out the threads is the point. At most, it would take out something just shy of a full turn. Or maybe I'm misunderstanding you.

I don't have a lathe but I do have a drill press. Chucking it in the press & lowering it down onto a grinding stone a little at a time might be better than the grinder -- more square & more controlled.

 

[bang]

Any means to remove metal paying close attention to squared.
I've used bench sander with a table for breech plugs.
Remove very little at a time.

 

[R Ellis]

Don't grind put it in a vice with a leather around it for padding and use a file you only take off a little and you can keep it flat if you need to practice try a piece of scrap JMO

 

[poker]

Taking metal off the threaded end of the drum will do nothing to change your clocking. You need to remove it from the shoulder where the threads meet the unthreaded portion. A lathe is recommended for that.
Some seem to think that you can just purchase undrilled drums in metric sizes, but Ive yet to see any for sale. So its grind that shoulder or use a shim washer. The shim washer works well, and the clocking can be adjusted by sanding the washers thickness.

 

[Phil Coffins]

The drum is a very important part to have correctly installed. Not only does it need to position the nipple in the right clocked position but also at the same time line up with the hammer from side to side. Let’s note forget the quality of the fit governs if it will stay in place. Once you have the drum blow out and bounce around the firing line you’ll understand why.

 

[The Crisco Kid]

If you use a grinder you'll probably wreck the drum in a hurry. Use a file. A three sided one works well. Put some kind of transfer stain, like lipstick, around the threaded hole in the barrel and install the drum. Back it out and the stain will be on the shoulder of the drum. File this area a little and repeat, repeat, repeat, until the nipple lines up.

 

[necchi]

Taking metal off the threaded end of the drum will do nothing to change your clocking. You need to remove it from the shoulder

I agree, I don't understand how removing the start of the thread will change the end shoulder/barrel contact(?)
It's doesn't matter where in rotation I "start" a threaded drum,, it still has to turn until there's shoulder contact.
I don't get it,,

 

[ord sgt]

The only problem I see would be the length of the threads on the drum insert and the thickness of the breech wall. Threads too long might stick out of the inner wall of the breech. That will have an effect on cleaning.

 

[poker]

Its not difficult to measure the length before you start, and then after grinding the shoulder grind the tip until you have the same length

 

[Nuthatch]

Using the drill press as an improvised lathe worked great. As advised, I used a triangle file freehand against the spinning drum & removed very little at a time until it fit. Making a very thin soapstone line along the shoulder helped me watch my progress.

A couple test pops with some caps showed promise. Looking forward to shooting this rifle in its new configuration. Thanks for the tips, all.