Caliber question.

[Kentuckyjed]

Did a search on the site but to no avail can't seem to find what I need. I picked up this trade gun/fowler in smooth, was told it was a .68 caliber, when I mic the inside of the barrel I get .770. What would be a good size for a roundball to shoot out of this? .750?
Thanks in advance.

 

[stank]

Is the smoothie you acquired an antique gun?
First off make sure it’s not loaded.
Some antique guns have bores that are worn at the muzzle so you need to know what the bore is all the way down to the breach. If you try to force a .75 ball down that bore and it’s actually .70 at the breach it’s gonna get stuck.
Get a wood dowel that is .75 and see if it goes all the way down. If it does , a .75 patched ball will probably be a good choice or a bit bigger for bare ball.
If the dowel goes down easy you can do one wrap of tape then 2 wraps until you find some combination that is just snug.
Don’t force anything down the bore until you know the correct diameter.
Good luck and be safe

 

[stank]

If .75 won’t go down. Sand or file material off the dowel until it will
Stank

 

[Kentuckyjed]

Double checked with another mic. I 'm getting .702 . Bore is bright and shiny no ball stuck or anything else.

 

[Kentuckyjed]

Is the smoothie you acquired an antique gun?
First off make sure it’s not loaded.
Some antique guns have bores that are worn at the muzzle so you need to know what the bore is all the way down to the breach. If you try to force a .75 ball down that bore and it’s actually .70 at the breach it’s gonna get stuck.
Get a wood dowel that is .75 and see if it goes all the way down. If it does , a .75 patched ball will probably be a good choice or a bit bigger for bare ball.
If the dowel goes down easy you can do one wrap of tape then 2 wraps until you find some combination that is just snug.
Don’t force anything down the bore until you know the correct diameter.
Good luck and be safe

I will try the dowel method. Thanks

 

[Kentuckyjed]

So if this is a .702 what would be a good size for round ball, .690?

 

[stank]

.69 ball

 

[centershot]

Wow! That's gonna' be a thumper!

 

[Kentuckyjed]

Yep

 

[flconch53]

So if this is a .702 what would be a good size for round ball, .690?

I would use a .68 ball. Probably were they got the caliber. It would be about 14 gauge

 

[Kentuckyjed]

I have used two different micrometers one digital .702 and one dial 45/64 I am getting for the bore diameter. So would a .690 work better or a .680 with a thicker patch. I set my mic at .690 and there is room in the bore just didn't want to have to ram a ball down there with a patch or just go patchless. Can't I have the best of both?

 

[flconch53]

It all depends on the gun
With no rifling it just isn't necessary to load them that tight. I load my 28 gauge (.553) with a .535 ball and .015 to .018 ticking and whatever lube I am using right then

 

[Kentuckyjed]

It is a smoothbore

 

[flconch53]

I know it is a smoothbore. It depends on the gun means the final decision is how it shoots and what it likes

 

[stank]

Either ball will “SHOOT” but you need to see what the gun shoots most accurate. Different patch and ball combos will probably shoot different. You need to find the load that shoots the best. Track of the wolf probably has everything you will need to get started. I would start with 70 grains of ffg powder.
Good luck and have fun

 

[Dusty_Traveler]

If you are sure about the .702, then I would use:

.690 RB for bare ball loads, and something .680 or less for patched ball loads.

Drop Jeff Tanner a line and he will build you whatever size you need. I put in an order for a .720 mold from him just the other day.

The dowel method mentioned above is good advice. I would definitely check the bore in several spots on the way down to verify its uniformity.

 

[Kentuckyjed]

Thanks everyone for the input/advice.

 

[hanshi]

My smoothbore is a 20 ga. That would be, from measuring with calipers, about 610" to .615". I shoot a .600" ball with a .012" (+ or -) patch. Accuracy is excellent with anything from 60 grns of 3F up to 75 grns of 3F. I shoot bare balls (.606") for good accuracy.

 

[Red Owl]

What everyone is saying is a ball about .10 under bore diameter is sort of the traditional, go to choice. Then play around with patch thickness.

 

[Kentuckyjed]

Yep, I really don't want to have to have several ball sizes or patch sizes would rather have the one size fits most. If I can't hit the target one way or the other not trying to make it rocket science.