What size round ball for .67 cal.

[Magnumjh]

Hello everyone, could you guys please recommend what diameter round ball to shoot in a .67cal tower pistol. Also what thickness patch and starting powder charge. Thank you all in advance for your help.

 

[musketman]

Just because it is called a .67cal does not necessarily
mean the barrelhas a .670 inch bore, but if it does, then usually there's a .015 to .020 reduction in ball size...

A .650 to .655 diameter ball with a .020 - .015 patch will do it...

 

[Magnumjh]

Thank you Musketman. That is about what I was thinking but I don't know much about smoothbores. I know in a rifled bore you want to use a tighter ball patch comb, but I wasn't sure about a smoothbore. I just started with one .

 

[SquirrelsaurusR]

A smoothbore doesn't need as tight a fit as a rifle because you don't need the patch to be squeezed into the rifling grooves, since there aren't any. As long as it's a snug enough fit to keep the ball in place so it doesn't move around in the bore, you're good. Rapine makes primitive-style roundball moulds in fifty different calibers, from .250 to .989. For your gun, they make a .650 mould and a .655 mould. Their website is down for now, but call them and they'll send you a free catalog.
(215) 679-5413
You might want to get a micrometer and measure your bore first to figure out exactly what size it is. Then call the guys at Rapine and tell them what you've got and they can help you figure out what you need. You could also load it with shot and use it for rabbits and squirrels (just don't shoot a Squirrelsaurus Rex if you see one :: ).

 

[musketman]

Magnumjh: You never did state if the barrel in steel or brass... if brass, you need to use milder loads, once you find them...

Also, check your state regulations, most smoothbore pistols loaded with shot could be concidered a sawed-off shotgun...

 

[Magnumjh]

I have shot it using #5 shot. It shoot a fairly good pattern at 15yards. A 16ga wad is just a very little bit loose so it is close to .67 as 16.ga is .66

 

Track has 13, 14, 15, 16, 17 guage wads for you. I expect you will need 15 or 14. They list the decimal sizes as well.
Daryl

 

[Magnumjh]

Musketman, I forget to say it has a steel barrel.

 

[musketman]

Musketman, I forget to say it has a steel barrel.

Good... ::

Steel barrels can handle higher pressures that brass ones...

 

In pistols, quite interesting, and one can only speculate as to the normal powder charges. Some are as low as 15gr. in a .60 cal pistol, apparently, by the cased measure with the pistol.
: I have a book on English Pistols, a Pictorial that has all the masurments and such. Beautiful photos, lefts and rigths and close ups on quite a few of them.
: About the brass barreled pistols - very popular as normal 'holster' pistols. The seeminly odd ones(in the book) are iron. What's intereing about these, most are swamped in form, and as I said, allthe dimensions are given, and simple arithmatic shows thickness that run from .01375" per wall to .040" being normal, at the swamp of the barrels in question. This is 13 and 3/4 thousanths of an inch for a barrel wall, about 2" back from the muzzle - and made of brass. For example, this particular pistol is .66 cal. and the barrel is 11/16" at the swamp. 11/16" is .68750" subtract .66, then divide by 2 for 1 side of the barrel. It's mate is .64 cal. same 11/16", so this one is really thick at - you figure it out. (hint, it's another .010' pr side.) Interesting stuff. BTW - the brass tubing that slides inside one another, has a .015 wall, thicker than the walls of this antique brass/bronze barreled pistol.
: This wasn't meant to detract from your post, musketman- brass does not have the strength of steel or iron for that matter, being that, all of them are flawless in construction.
Daryl

 

[Shiloh]

I know this is an old thread but I have a similar question.

I have a bore that measures .685. that seems like an oddball bore size. I'm thinking a .015 patch with a .655 ball.

Opinions please.

 

[User_Dan]

I know this is an old thread but I have a similar question.

I have a bore that measures .685. that seems like an oddball bore size. I'm thinking a .015 patch with a .655 ball.

Opinions please.

Marty arms molds makes some large round ball molds. A 660 may be good for you.

 

[rickystl]

I know this is an old thread but I have a similar question.

I have a bore that measures .685. that seems like an oddball bore size. I'm thinking a .015 patch with a .655 ball.

Opinions please.

TOTW has some .662 round balls available. You might try that before investing in a mold.

Rick

 

[rickystl]

Generally, you want to use a ball size 2-3 calibers smaller than the nominal bore size. If the bore is a true .670 (or close to it) TOTW has .648 round balls available that you can try out before investing in a mold. I've found these large caliber smooth bore flint pistols shoot decent out to about 15 yards using 30-35 grains of FFG in the barrel and 3F in the pan.
But as mentioned above, best to mic the bore first. It might say .670, but could be off by as much as one-caliber.

Rick

 

[ZUG]

Measure your bore's I.D. then get a ball 0.020" under that and then get patches that will give you a snug fit - not tight - when you ram it down the bore. Easer to change patch thickness then to keep buying different size balls. Your smooth bore pistol is NOT a "sawed off shotgun"

 

[Gopher0]

I have shot it using #5 shot. It shoot a fairly good pattern at 15yards. A 16ga wad is just a very little bit loose so it is close to .67 as 16.ga is .66

I use a 16ga cup works well in my 69 Cal