Anybody heard of a .6115 bore?

[Gooddaytoya!]

Since the breech plug is now working right and the barrel is now shiny clean thanks to everyone's help, I decided to slug the bore from the breech end since I never did know the exact dimension. My plan was to use the information to rationally and without blind guesses select as close as possible the right round ball and patch combination (As some may remember, the first 6 in of the muzzle end has been tampered with by a really good gunsmith who did his best to make that part of the barrel better. So there's no point in slugging the barrel from the muzzle. That's a story not worth telling.) I used an oversized round ball that I squashed a bit by tapping it with a hammer, to make sure it would fill the entire space within the bore. It went six inches in with typical difficulty, popped out with little resistance, and looks like I would never have expected it to look. The slug is hexagonal with rounded corners, probably about 5/32 or 3/16th inch radii. I took it to a machinist so the plug could be measured from flat to flat with a good micrometer. Does all this make sense to anyone? By what it looks like when I shine a light down the bore, I wouldn't have expected the slug to have that shape. Maybe it's hard to guess at the cross section of a spiral that plunges down into a rifle bore.
But this slug doesn't lie right?? Another thing about the slug is that it has two very thin straight lines on it which make me think that the rifling was made using the button method. A rotating cutter on a milling machine wouldn't leave those kinds of longitudinal grooves in the barrel, right? Therefore I assume this barrel was made with contemporary methods. It wouldn't bother me if the barrel had some longitudinal striations in it, as long as they follow the twist of the rifling. Does this long-winded post make sense?Any feedback? This is very interesting to me.

 

[oldwood]

Dixie catalog chart says a .615 is close to 20 ga.

 

[sawyer04]

If I get the jest I wonder if the barrel was originally rifled in the Wit worth style and re=rifled. Some of the old timers were actually rifled in a hex shape. Interesting, I wonder if the barrel started as a .58 and re=worked out to 20 guage.

 

[Gooddaytoya!]

Dixie catalog chart says a .615 is close to 20 ga.

Ya close but no cigar LOL. Ever tried putting a shot cup in a rifle? I did with my swivel gun using small bird shot, and the pattern was a huge useless donut. What a noob I was, but my friends were doing the same silly experiments.

 

[Gooddaytoya!]

My apologies, by no cigar I meant that a 20 gauge round ball (.615) would have no clearance for a patch in my rifle. But it just occurred to me, I could put in about 50 grains of FFG, a felt wad, push in a 615 round ball, lightly lube the barrel after loading, fire it and see what happens. It could possibly be fun. It would probably cause lead to scuff off onto the barrel, and the ball wouldn't rotate, and gases could get by through the rifling grooves causing fouling, but it still could be an interesting experiment. In reality it looks like I'm headed to a .575 ball and a thick patch. Unless I can find a 590 ball somewhere. With a one in 60 twist there's no point in trying elongated boolits.

 

[Gooddaytoya!]

If I get the jest I wonder if the barrel was originally rifled in the Wit worth style and re=rifled. Some of the old timers were actually rifled in a hex shape. Interesting, I wonder if the barrel started as a .58 and re=worked out to 20 guage.

But I have to ask, what good is a 20 gauge rifled barrel? Maybe 50 or 70 years ago there were round balls that fit this barrel. None that I can find now. If I could, I would choose a . 590 round ball plus suitable patch. I certainly can't afford to have a custom round ball mold made just for this old rifle.

 

[Gooddaytoya!]

But I have to ask, what good is a 20 gauge rifled barrel? Maybe 50 or 70 years ago there were round balls that fit this barrel. None that I can find now. If I could, I would choose a . 590 round ball plus suitable patch. I certainly can't afford to have a custom round ball mold made just for this old rifle.

 

[Gooddaytoya!]

X

 

[Grenadier1758]

@Gooddaytoya!, the 20 gauge designation is just that. You have a rifle with a bore diameter that is approximately 20 gauge. Having rifling will exclude using shot in the barrel and the actual bore dimensions will prevent using shot cups unless you make a paper shot cup to your dimensions. So don't get all wrapped up in the barrel dimension terms other than the actual dimensions.

Now, is 0.6115 the dimension from the lands or from the bottom of the grooves. Get a ball that is about 0.010" less in diameter than the land to land diameter of the barrel. Use a patch that lightly compresses to 0.005" + the groove depth for your patch or just wing it with a 0.015" patch that you you lubricate as you load it. Now that you have some dimensions, you can begin to develop a load.

 

[sawyer04]

But I have to ask, what good is a 20 gauge rifled barrel? Maybe 50 or 70 years ago there were round balls that fit this barrel. None that I can find now. If I could, I would choose a . 590 round ball plus suitable patch. I certainly can't afford to have a custom round ball mold made just for this old rifle.

It might not have used a patched ball, very well could have been a skirted slug. Minnie ball, I would be curious if it will swallow a 20 gauged slug, hollow based. As Oldwood stated ,20 guage slug mics out 0.615, might be a snug fit.
I don't want to ruffle feathers, but are you dealing with an actual barrel that's meant to be charged and fired? I know, stupid question, but I am known for asking them. I ask from experience of a young man toting a weapon in the shop that wanted it inspected before he fired it.
I am here to say that thing was immaculate, real lock that worked and vent hole, later to found drilled by previous owner. Just to look at the thing it was ready to charge. What gave it away the breech plug was just pressed in and the rifling didn't look like rifling, it was some kind of scoring. It was made in Europe for show. Dang if I can remember if we checked the caliber or not. I think after we found the breech just pressed in and that was the end. Yes the cock and hammer sparked, but it was a Spanish lock, resembled a CVA lock at the time. Been a while back in the early 80's.

 

[Gooddaytoya!]

"is it a real gun meant to charged and fired?". Damn good question. I'm going to have Rusty look at it before I buy any balls or molds. Although, I have fired it about 100 times, but you never know this gun is so weird I might have survived by sheer luck. You guys come up with really great comments and suggestions.

 

[Gooddaytoya!]

@Gooddaytoya!, the 20 gauge designation is just that. You have a rifle with a bore diameter that is approximately 20 gauge. Having rifling will exclude using shot in the barrel and the actual bore dimensions will prevent using shot cups unless you make a paper shot cup to your dimensions. So don't get all wrapped up in the barrel dimension terms other than the actual dimensions.

Now, is 0.6115 the dimension from the lands or from the bottom of the grooves. Get a ball that is about 0.010" less in diameter than the land to land diameter of the barrel. Use a patch that lightly compresses to 0.005" + the groove depth for your patch or just wing it with a 0.015" patch that you you lubricate as you load it. Now that you have some dimensions, you can begin to develop a load.

Land to land.

 

[Gooddaytoya!]

It might not have used a patched ball, very well could have been a skirted slug. Minnie ball,

 

[Gooddaytoya!]

Interesting suggestion, but this rifle has a 1 and 60 twist. I know better than to ask this, but is it possible this rifle could shoot a skirted ball well? Maybe the odd octagonal rifling could work with a mini? Still, I have to show it to Rusty.

 

[sawyer04]

"is it a real gun meant to charged and fired?". Damn good question. I'm going to have Rusty look at it before I buy any balls or molds. Although, I have fired it about 100 times, but you never know this gun is so weird I might have survived by sheer luck. You guys come up with really great comments and suggestions.

I would say 100 times would be a fairly good test. a twist of 60 will fire a minnie ball or patched ball fairly well from my experience. Keep us in tune. Good luck

 

[BadDaditood]

Interesting suggestion, but this rifle has a 1 and 60 twist. I know better than to ask this, but is it possible this rifle could shoot a skirted ball well? Maybe the odd octagonal rifling could work with a mini? Still, I have to show it to Rusty.

Octagonal or hexagonal (Whitworth) ?

Not sure if I like the nickname “Rusty” for a gunsmith…. I suppose it’s better than “Hacksaw”

 

[Grenadier1758]

I should have mentioned this before. Radiused grooves (round bottom) will often appear to be more polygonal based on the number of grooves. How well such a rifle would shoot a Minie' ball is dependent on the depth of the grooves and if the diameter of the Minie' ball is 0.001" to 0.002" smaller in diameter than the land diameter. @Gooddaytoya!, finding a Minie' ball that is 0.610" in diameter is not going to be easy. Stick with a round ball of 0.600".

 

[nkbj]

But I have to ask, what good is a 20 gauge rifled barrel? Maybe 50 or 70 years ago there were round balls that fit this barrel. None that I can find now. If I could, I would choose a . 590 round ball plus suitable patch. I certainly can't afford to have a custom round ball mold made just for this old rifle.

Got a Green Mountain drop-in smooth barrel rifled for round ball, TC flinter Hawken.
.595 round ball mold.
I like it a lot.

By the way, I have a .588 diameter minie mold and threatened to brown paper patch and dip them in melted lube but haven't bothered with trying it yet. Would be fun. Maybe some day.

 

[nhmoose]

What did you use to measure with?