drill bit size for hole into chamber

[Steve Weems]

I have relined Model 1861 musket barrel cut to carbine length. Need to drill hole into firing chamber and will go thru the clean out screw hole to do so.
what size drill bit would be appropriate for this role to be?? Help would be appreciated!----Steve W.

[ms3635v]

Using +/- .001" pin gauges, the hole measures .083".

[Hal]

A #45 drill bit is .082". Drill bits usually drill a hair over their diameter anyway. I'd bet a #45 would be close enough.

[Steve Weems]

Thanks to both Mike and Hal for their advice. I?ll try the no. 45 and see if it goes bang!?- Steve W.

[Steve Weems]

I used the no.45 drill bit to drill the flash hole. I dropped a bobber light down the barrel afterward and was relieved to see it resting on the breech face by looking thru the clean out hole. I knew if I had drilled into the breach plug that would be a big problem.!
thanks again for the advice here and now I can go out and fire it. ?-Steve W.

[Steve Weems]

I used the no.45 drill bit to drill the flash hole. I dropped a bobber light down the barrel afterward and was relieved to see it resting on the breech face by looking thru the clean out hole. I knew if I had drilled into the breach plug that would be a big problem.!
thanks again for the advice here and now I can go out and fire it. ?-Steve W.

the No.45 drill bit did the job? test fired today with no problems. Steve W.