smoothbore offset bore

[Scott Bumpus]

If a person was to make a barrel for smoothbore shooting, and was to offset the bore, like runout on purpose,  how much offset would be needed in a 54 cal  to hit at around 50 yards.  i know they usually bend the barrel to do this, i just thought this might work.  anyone have the ballistics for a 54 cal  where this could be calculated?  thanks

[Robby]

Scott, I'm not sure just what your trying to achieve. Hit what at 50yards, and how would an offset bore help you accomplish this?
Robby

[Scott Bumpus]

Most smooth bore competitions will not allow a rear sight.  The common method is to bend the barrel upward to bring the impact point up.  The offset or runnout would put some built in elevation allowance.

[bob in the woods]

I have built and used a few smoothbores, and some shot well ,ie, they were on target, without bending the barrel. The elevation is a matter of sight picture..shaving/adjusting the cheek etc. The point is, until the gun is done and fired, you don't know if you will have to bend the barrel or not, and you don't know which way you might have to bend it. How do you build in offset, when you don;t know how much if any and which way?  I've only had to bend/straighten one smoothbore barrel to get it to shoot.  Mainly I've gone back and adjusted the cheek to stock fit. Hope this makes sense.

[Jerry V Lape]

Bob just beat me to it while I was typing.  Construct the stock to give you a sight picture a little like a trap gun where the point of impact is going to be above the line of sight.  Build the stock with an overly high comb line and then before you finish it, go to the range and shoot it in.  Rasp or scrape off the comb line until the ball is brought down to your desired 50yd point of impact.  There is a rule of thumb used on modern shotgun stock bending which provides a 1/16" change on the stock produces a 1" movement of the point of impact at 16 yds.  This gives you some idea of how much extra wood to add on before you start shaving it into your alignment.  It won't take a lot to do this as the upward angle you are trying to create is only as much as the angle between barrel, front and rear sight on a rifle.  Of course this offset is only going to be valid for one particular load - but this is the same for your offset barrel.