touchhole placement question

[aragorn]

The advice I've had is to position the touchhole 1/16" ahead of the breech plug face.

As I'm installing a Chambers 'White Lightning' touchhole, with the interior cone 1/4" wide, wouldn't it make more sense to position the touchhole itself 1/8" ahead of the breech plug face? (By 'touchhole' here I mean the exterior pinprick hole itself). That way the entire interior cone would be ahead of the plug, exactly abutting it at the breech end.

I know if the cone overlaps the plug I could file a channel in the plug, but it seems to me a whole lot easier just to position the entire touchhole liner 1/16" further forward, with no obvious disadvantage to ignition (as far as I can see it anyway, but I may be wrong).

I'm just asking this question now so I can inlet the barrel into the stock at the breech end so it lines up at the best touchole position with the flashpan. I won't actually be drilling the touchhole until I've installed both barrel and lock.

All advice much appreciated.

 

This is not one of the curcial factors in the build.

You will find that the touch hole liner cone does not extend to the edge of the threads anyway. There has to remain some meat on the base so your cone is not 1/4 tapering to the touch hole but more like 3/32 tapering down to .050 for the touch hole,(which you will need ot ream out also, it is not a pinprick).

All of this detail worry over noncriticals will give you an ulcer!

Save your concentration for making the foreward lock pin clear the ramrod hole!

Other than that see signature below.

:front:

 

[aragorn]

Thanks. Getting the touchhole right seemed pretty critical to me. Until my books arrive I'm working solely from the Turpin video from Chambers - it's excellent and gives me all I need in most respects, but one area it doesn't cover is the touchhole. Hence the question.

 

[Birddog6]

It all depends on the barrel type, caliber, barrel dia, dia if the breechplug & etc. I prefer to have my vent liner threads not touching any of the breechplug threads. And I like my vent liner threads ahead of the face of the breechplug face so my vent is about 1/8 to 3/16" from the face of the breechplug. Much less chance of fouling buildup at the vent hole & also less chance of pushing fouling into the vent hole when swabbing the bore, if you are a person that swabs between shots.

Others prefer to have the vent right at the face of the breechplug, some have it back a lil more & cut a groove in the plug face.. really depends on what YOU want .

:results:

 

[aragorn]

Thanks Birddog6. I'm glad you mentioned fouling because that was exactly one of my concerns, especially as I do usually swab out between rounds. I'll probably aim to place my touchhole more or less as you do.

 

[TANSTAAFL]

Thanks. Getting the touchhole right seemed pretty critical to me. Until my books arrive I'm working solely from the Turpin video from Chambers - it's excellent and gives me all I need in most respects, but one area it doesn't cover is the touchhole. Hence the question.

Liability factors, it is just an inert wall hanger before the TH, after that it should go bang, and if it don't go bang right, who ya gonna call? Too bloody many call their lawyers.

 

[TANSTAAFL]

Some freak out if they see the pan fence not perfectly aligned with the end of the breech and a little wood is showing betwixt the two. when working from a pre-carve, depending upon how much inletting has been done, there may be very little choice in the matter of TH placement, it could have already been predetermined.