vent liners

[flaming canvas]

Has anyone done any experimenting with the merits of different sizes- 1/4 vs 5/16 ? I have guns with both sizes and it seems to me that the larger size liner might be consistently a little faster.

 

[RC]

just seems to me,,seein how the pressure moves the ball out,,,the less pressure you have blowin back out the touch hole,the easier it'd be to "regulate" your load...so to me (or IMHO) as long as the gun goes off the hole is big enough...if you have problems gettin gun to go off then drill.. but, thats just me.... :thumbsup:

 

[roundball]

Has anyone done any experimenting with the merits of different sizes- 1/4 vs 5/16 ? I have guns with both sizes and it seems to me that the larger size liner might be consistently a little faster.

You must not be talking about the size of the touchholes being 1/4" or 5/16"...you must be talking about the sizes of the threaded seats??

 

[Rancocas]

I can't see where the size of the "vent liner" would make any difference whatsoever. It is the size of the touchhole that matters.
None of my flintlocks have a vent liner. I made the guns and I just drilled a 1/16" touchhole and coned it very slightly. They all work fine.

 

[CoyoteJoe]

I think you're probably right about 5/16 being better than 1/4". Reason being that the larger size can have a larger counterbore or inside cone while still maintaining a reasonable thickness to the thread walls. The whole point of a vent liner is to bring the powder charge closer to the prime. If the interior counterbore is too small then 2f powder will not enter, 3f maybe OK.
Manufacturers of vent liner tend to be understandably cautious, who needs a multi-million dollar law suit over an item which retails for two bucks? However, I believe their caution may be excessive and that the interior counterbore can be enlarged somewhat, deepened somewhat, and a shallow cone added to the exterior and when so done performance is greatly improved. Still, if one intends to shoot 2f powder I would prefer the 5/16" vent liner.

 

[bioprof]

I saw a post on another discussion forum where a builder made an internal coning tool from a small finishing nail. He just hammered the head of the nail flat and filed the sides so that they were sharp, hardened it, and stuck the shaft of the nail into the touch hole from the inside of the barrel, chucked the nail in a drill and coned the inside of the barrel. This alleviates the need for a liner to get fast ignition.

I've also seen another more elaborate coning tool that had a threaded shaft that fits into the cutting head. You put the cutting head into the inside of the barrel, push the threaded shaft into the touch hole, thread the shaft into the cutting head and cone away.