69 call Roundball Question

[Paul L]

Hello All, I am a bit confused (not unusual) on the subject of Roundball size. When I first started shooting smoothbore, a few years ago, I was told you want a ball size that is as tight as possible but still allow you to load. So basically .004 (or so) under bore .
After reading several articles published on this bb, and in the Skirmish line is seems a lot of people are using a ball size that could be .010 (or more) smaller than the bore. A ball size of .678 seems to be very popular.
Is there any “real” reason one should use a ball so much smaller than the bore? I know it comes down to what works, but am trying to understand the rational for using a looser fitting ball over a larger one.
Thanks!
Paul - 15th Virginia Cavalry

[Rich Foster]

Paul, What you want to accomplish is be able to load your smoothbore without hardly any resistance getting ball down the bore. Any tightness can change pressure on firing which would change impact point. Back 13 or 14 years ago shooting a smoothbore was like shooting a slingshot put a round down the barrel and hope you hit something. It has been found that a smoothbore can be shot very accurately and consistantly by cetain people who were glad to let everybody know. Now one soution does not fit all smoothbores but it gives you a better starting point to start from. If it was simple every rifle musket would shoot the same bullet, powder,lube and be successful. RIch

[Maillemaker]

I'm no expert on this. I don't even own a smoothbore yet. But one of our team members has let me borrow his, with ammo, at skirmishes. He sent it along when he could not come. He sent it with a target that said "Aim here" with an X on it.

I did, and holy crud, I was as accurate with that thing at 25 and 50 yards as I am with my carbine at 50 and 100!

I suspect it is his precision ammo. The balls, when they went down the barrel, acted like an air shock for the ramrod - you could feel it "bounce" on the cushion of air as the ball went down.

It's a fantastic gun to shoot.

Steve

[tony 1st regt]

many, but not all of the US smoothbores are about .690. The reason many use the .678 ball is because it was/is available especially years ago when SB became popular at N-SSA. I shoot a Jeff Tanner .684 with good results. As with most BP shooting lube plays a big role in allowing you to continue shooting after a few shots. Powder charge is also important, you want that ball centered in that barrel for accuracy, so the windage between the ball and the barrel is important. As you stated they can be very accurate, from a bench @ 25yds my H&P with a Hoyt barrel makes a 10 shot hole that can be covered with a silver dollar, when shot from my shoulder a lot bigger.

[Paul L]

Thanks Tony!
That answered my question as to why so many use the .678size.
Paul
15th Virginia Cavalry

[Paul L]

Thanks Harry! Excellent explanation of why the ball is so much undersized to begin with. I will have to rethink my approach on casting the round balls(and what I have been told earlier). I knew about the Alox, but just never could figure out why the original ball was so undersized. Now I have a much better understanding! Thanks! Paul

[efritz]

Dear True Blue,

Harry,

I once spoke to a major manufacturer of moulds about making me a RB mould with dimples like a golf ball. He stated that it only works on golf balls because of the speed. Golf balls being much slower than a RB in front of 60-80 grs. of black powder. I don't know if he was blowing black powder smoke up my butt but that's what he said. Also, depending on what you are ruffing with can make a difference. The ruffer the ball or the indents of ruffing can actually make the ball bigger than the bore. If one uses the furrier files and depending on which side you use and how hard you press can make the difference. Remember, this is not a sport. It's a science. You're completely right about all else.

I don't know what it is about Alox but it's all that works for me. I've exhausted myself trying to get my gun to shoot with my lube. With Alox it'll hold ten ring. With my lube it uses the entire paper. Go figure.

[Mike Stein]

A pimpled round ball mold would be fairly simple and possibly a do it yourself project but a dimpled would require a lot more engineering.