.730 bore...what size ball?

[mark davidson]

I measured my bore on my smoothie 12 guage yesterday. It is .730 the best I can tell at the muzzle. What size ball will I need? I notice TOW sells both .690 and .715 size balls. Which do you guys suggest for my bore size .730?  Also a "suggestion" would be nice for a starting load for shooting deer. :-)

[Sir Michael]

I'd have to recommend the .715 for the .730 bore, .690 leaves way too much space to fill up.  You should also start with as thick a patch as you can find, .020 if that is too tight try .018 or .015.  This combination should produce a tight fit.  I shoot a .600 in a .620 bore with a .010 patch.  It loads snugly and shoots better than I do (no rear sight makes things a bit dodgy.  

[mark davidson]

SM, Thanks! I was leaning toward the .715. However, a .015 patch wraps around the ball on both sides so to speak adding .15 on both sides of the calipers. .715 plus .015 would be a perfect fit.....but .715 plus .015 on both sides puts me .015 over. Will the patch and ball crush fit to the .730 bore?

[mario]

Where I would start:

70gr 2F, .715" RB, wadding.




Mario

[hawkeye]

Does your 12 gauge have any choke to it?  Usually 12 gauge guns shoot a .690 round ball as their bores are .72 caliber.  If your ball is too big, you won't be able to patch it and you'll have to shoot it bare like a slug (overpowder card / wad, ball, overshot card).  That is how I shoot my Brown Bess musket with .735 round balls.

[Sir Michael]

The .015 patch should compress around the circumference of the ball.  You can always find some one who needs some .015 patches or you may be able to use them with a different gun. :hey-hey    :rt th  :shock: Go figure.  :peace

[Capt. Jas.]

If I am going to shoot PRB in a smooth bored gun I prefer a heavy patch and smaller diameter ball.

Don't forget to also try it bare with wadding which seems to be the more historical way to shoot a single projectile in a smooth gun. Some guns really like it.

[mark davidson]

Thanks to all. Hawkeye, my gun does not have any choke to my knowlege. Calipers , best I can read them, say the bore is .730 at the muzzle.  I never thought about trying it without a patch...would the over shot card on top of the ball not play heck with accuracy? I will just order some .715s and some .690s and see what it likes. Two different size patches won't be that expensive to experiment with either.
  Sir Michael, Kinda like you mentioned with your two .62s....I have two .62 cal rifles and one of them likes a .610 ball with a .015 patch and that combo will hardly drive down the barrel of the other rifle which prefers a .600 ball and .015 patch. It is hard for me to understand why tolerances are so "loose" in this black powder barrel industry. Imagine what would happen if say .30 cal centerfire barrels were off or differed by 10 thousandths between barrels!!  Are most top brand MLer barrels not cut on modern equipment???