vent liner question

[deepcreekdale]

I have a customer project; a nice percussion rifle he got off Gunbroker. He wants it to be converted to flint. The lock is no problem since it is a Siler large percussion and I have several Siler large flints in stock. The percussion drum is tapped 5/16-24. Not the greatest drill and tap job I have ever seen but should be serviceable. I prefer Chamber White Lightning liners which are tapped 5/16-32. I could just buy a 5/16-24 vent liner and screw it in but since I have a few dozen WL liners, and I really do like them, would prefer to use one. Any ideas? I was thinking of redrilling/tapping with a plug of say, 1/2-24 installing that, and then redrilling and tapping for the 5/16-32 threads. That seems like more work than necessary because then it would involve refinishing/rebrowning the barrel around the vent. Has anybody else dealt with this?

[RAT]

What about drilling out the hole for a 3/8" liner? Chambers sells them in that size. Then you will have a proper thread fit.

[D. Taylor Sapergia]

Chambers also makes a 3/8" x 32 White Lightning Liner.  It requires a special drill bit.  I have an extra set, tap and drill bit,  if you'd like to purchase one?

[bluenoser]

The tap drill for a 3/8 x 32 white lightning liner is a Q, which is a standard letter drill size.  It is the 32 TPI tap that is a bit of a challenge to find. Three eighths by 32 TPI is a standard UNEF (Unified National Extra fine) thread.

[Dphariss]

If you dig MSCdirect.com will have the tap and the drill is a standard item. This should get you there>
There are otehr suppliers. Can’t find country of origin on most of these.

https://www.mscdirect.com/browse/tn/Threading/Taps/Straight-Flute-Taps?navid=2106035&refinements=3AStraight%20Flute%20Taps--Tap%20Type%3AStandard--Thread%20Size%20(Inch%20-%200%20Decimals)%3A3%2F8-32

[Dphariss]

I think you can get all the needed items from Chambers anyway. All at MSC seem to be H3 tolerance which is .003 oversize.

[Dphariss]

I always think MSC first. Here is where you need to go.

https://www.flintlocks.com/parts.htm

[smylee grouch]

IIRC  Track of the Wolf also sells the tap and  drill.   

[FlintFan]

I think you can get all the needed items from Chambers anyway. All at MSC seem to be H3 tolerance which is .003 oversize.

A H3 tap is +.0015

Every "H" is .0005

[deepcreekdale]

I have all the drills and taps andI have plenty of the 3/8 White Lightning liners as well. I should have mentioned that the barrel is on the skinny side, I hate having the liner extending well into the adjacent flats. I was just wondering if someone had a different solution. But thanks for all the input.

[Scota4570]

Make a 5/16x24 out of an allen head grub screw?