Still Newbie

[schluterjohn]

I have now read Ned Roberts book and the book by "Dutch" Schoultz and now know enough to be dangerous. I have also delved deeper into the dimensions of the antique cap lock by R. Constable. It probably is a presentation picket rifle circa 1840's. The unrifled false muzzle with a pronounced funnel shaped bore remains a puzzle but the pins match up perfectly and do NOT go all the way through the false muzzle so not predrilled before removal from any barrel. Not sure how that was accomplished without quality computer aided layout equipment. The bore of the smooth false muzzle is 0.003" smaller than the bore of the rifle. Would a small crown on the rifle muzzle (about 0.003") prove useful to prevent damage to the patch? Second: measurement on the slug from the barrel are still confusing. The groove size is easy with the mikes but can't use the good point or ball mikes on the soft lead without some local distortion. The caliper measurements vary leading me to believe that the land does NOT have the same curvature as the bore. Has anyone run across any of the old riflemakers using a flat cutter rather than a curved one? Because that is what I'm coming to believe from all the time I've spent measuring the slugs. I still cannot determine the twist despite disassembling and inspecting my Dewey rod bearings and varying the patch thicknesses. Visually, there is a step between land and groove but the measurements indicate a very small step. Fits with the inability to spin the rod to determine the twist. At the center of the rifling, I get about 0.004" consistently but adjacent to the land the depth is less. Seems wrong. But I don't plan to cut a thin slice off to use on the comparator. Any thoughts?

[Daryl]

That the muzzle was drilled after separation or a different piece of steel is likely why it is smooth. The bore of the false muzzle being .003" smaller than the rifle's bore (do you mean groove?) is
puzzling.  If the FM's bore is smaller than the rifle's bore, the false muzzle is doing nothing. Might as well shoot a .003" undersized ball or bullet with card wads.
If you mean the bore of the FM is .003" smaller than the groove diameter, then a slightly crown would be all that is necessary on the muzzle.
Flat bottomed cutters for cutting grooves was used in the late 1800's for bullet firing rifles. The grooves would be deeper in the corners, than the middle of the groove- like Henry or Pope rifling.
Henry had sharp corners in his rifling, however Pope's was rounded, but still deeper than in the middle, due to the flat bottomed rifling.
If the patch is tight enough on the rod, even a hickory rod can be used to 'find' the rate of twist. The rod will WANT to twist with the rifling, just don't try to stop it form turning.
Your Dewey rod should work perfectly. Taylor and I used my .35 cal. and up Dewey rod to cast a plug and lap a barrel. We did this twice & salvaged a barrel that was badly pitted from using boiling water for cleaning by the owner.
If the grooves are shallower at the land corner, then the rifling cutter was rounded. Deeper in the middle would be impossible, unless there was also a radius like Pope barrels and you are measuring on that radius.

[T*O*F]

I think you are confusing a false muzzle with a bullet starter.  They are two different animals.

1.  A false muzzle is actually cut from the barrel and maintains the rifling.  It is slightly coned at the top and swages the bullet into the bore so the rifling is engraved on the bullet; ie, a mechanically fitted bullet.  Often, the false muzzle also incorporates a provision to pick up a paper or linen patch on its way down.

2.  A bullet starter is just that.  However, it allows an oversized/tight patched ball to be swaged into the rifling.

[Scota4570]

Sounds like you may be describing Pope rifling.  The picture is for the general shape here.  Disregard the dimensions.

[schluterjohn]

Daryl, yer right about the groove/bore mixup. Second time. Old age disease! Will try a slight crown. No Harm. But I'm still not holding my mouth right since I can't get the Dewey rod or a machined dowel to spin. Works on every other rifle I have but the gods aren't in my favor on this one. Hope this doesn't mean it won't spin a patched bullet!
The false muzzle is obviously mis-named. It's gotta be a repacement, but still confused about the machinist's ability to align the pins that precisely. The matching starter has a tip that precisely fits the nose of the belted picket bullet from the mould. Interesting info on the Henry/Pope straight cutter rifling. My lands and grooves are more equal in width, however. Like I said in the earlier post, I can't really get a firm handle without cutting a thin slice from the muzzle and I ain't doing that.
Roberts talks about linen circular patches for the picket but doesn't supply any detailed info on the patch or fit. Anybody shooting pickets in the forum? Could use some detailed patch info.
And a sincere thanks to all who are putting up with my questions.