Cal of muzzleloader barrel

[buddy3658]

I have a antique muzzleloader rifle im trying to find out what cal it is can anyone tell me a easy way to tell what cal it is .It was made in the 1850' if that matters. Thanks Tim

 

[Black Hand]

Measure the diameter from land to land (if it is a rifle) or inside diameter (if it is a smoothbore) with a dial micrometer. The measurement will tell you the caliber (i.e. 0.500=50 caliber, 0.540=54 caliber, etc.).

 

[Zonie]

If just an approximation is good enough you can use a ruler or tape measure to measure the bore size at the muzzle.

5/16 inch = .31 cal

3/8 inch = .38 cal

7/16 inch = .44 cal

1/2 inch = .50 cal

9/16 inch = .56 cal

5/8 inch = .62 cal

If you want an accurate measurement you will have to use something like a dial or digital caliper which can measure inside dimensions, outside dimensions and depths to a thousandth of an inch.

By the way, these calipers are not that expensive.

 

[buddy3658]

Thanks everyone I used a dial micrometer and I have a 38 cal or .380 thanks again .Tim

 

[Birddog6]

Unless the rifling is directly opposing at the muzzle, it is hard to get an accurate measurement.

Best way I know is use a indexed drill bit set & insert the Uncut end of dif. drill bits into the bore, going up in size on each one til ya find one that is snug. Find one that barely fits & it will be within a couple thousands of the actual bore size. Make sure the bore is clean & oiled before doing this, and do NOT force the bit in.

Keith Lisle

 

[user 13289]

Another route: drill a hole in a slightly oversized pure lead ball, peck ball into muzzle with brass hammer, pull the ball back out with screw twisted into the hole. measure ball.

 

[Zonie]

Or, if you don't want to futz with drilling holes in the ball and you have a solid brass rod that fits the bore you can drop the rod into the barrel, tap the lead ball into the muzzle and then shake the barrel so the rod pounds the ball back out.

 

[bpd303]

Yep...done that several times, works like a charm. Just make sure the rod is short enough to act as the hammer for tapping the ball out. The first time I did it the rod was too long and didn't have enough travel.

 

[Birddog6]

Well, yes, you could slug it.... But that is allot of trouble on a old ML just to be able to say "Yep, it is a .40 cal". :idunno:

Keith Lisle

 

[bpd303]

True if all you are going to do is hang it on the wall. However if you want to shoot it an accurate measurement is best and I want to shoot all of mine.

 

[Birddog6]

:grin: OK. I thought he asked for a "Easy Way" to find out the caliber & what I posted is the easiest way I know. :idunno:

Keith Lisle

 

[user 13289]

yup, i missed that.

sometimes i reed too fasterer. :v

 

[Dave K]

Yep, that is what different thickness of patching can be used. You get a close size of the bore with the drill bits and after than it is the patching. It is not rocket science. I do have adjustable hole gauges, but before that, it was drills bits I used for a go/no go gauge. Always worked good for me.