Jug choke

[Berk]

The other post about adding jug choke to your barrel got me to wondering what that would do to round ball accuracy. Has anyone put jug choke in a barrel and and fired round balls through it. What kind of a group did you get.

Also has anyone ever shot round ball through a gun with modern choke. I have a barrel that is 20ga Mod. that I have been thinking about making a canoe gun out of. It will be used for shot but wondering about what a round ball would do.

Berk

 

[roundball]

The other post about adding jug choke to your barrel got me to wondering what that would do to round ball accuracy. Has anyone put jug choke in a barrel and and fired round balls through it. What kind of a group did you get.

Also has anyone ever shot round ball through a gun with modern choke. I have a barrel that is 20ga Mod. that I have been thinking about making a canoe gun out of. It will be used for shot but wondering about what a round ball would do.

Berk

A "jug choke" is not a choke like you're probably thinking...it actually adds no physical constriction to the bore what-so-ever.

A Jug choke "creates" a choke effect by it's design...and to make a Jug Choke, metal is actually removed from the bore with a hone, as opposed to adding metal constriction.

A typical Jug Choke is created in 3 sections, starting just inside the muzzle...it consists of a 3" expansion chamber, with a 1.5" tapered forcing cone shaped on either side of it.

The expansion chamber might be honed out .010-.020" over bore size, and the choke effect is created by the shot column expanding slightly into the expansion chamber as it's passing it, then being tapered/forced (choked) back down to cylinder bore prior to muzzle exit.

These dynamics of expanding, then reducing, the diameter of the shot charge acually results in a tighter pattern of shot...but as you can see, no physical constriction has been added...so round balls are not effected by any physical reduction of the bore's diameter...they might still be affected, dunno, but not from the bore being any smaller/tighter than it was.

 

[Berk]

I was wondering if when the ball reached the choke what effect would the gasses escaping arond the ball would have any effect.

Berk

 

[rudy parnell]

It seems logical that the patch would fall away from the ball at a distance removed from the muzzle at which time the ball would cease to be a patch round ball and would at such time become a" so low round ball". GEE WHIZ! :blah:

 

[musketman]

A Jug choke "creates" a choke effect by it's design...and to make a Jug Choke, metal is actually removed from the bore with a hone, as opposed to adding metal constriction.

A typical Jug Choke is created in 3 sections, starting just inside the muzzle...it consists of a 3" expansion chamber, with a 1.5" tapered forcing cone shaped on either side of it.

 

[roundball]

"By Jove, I think you've got it"....

PS: one minor tweak to your graphic...as the Jug Choke gunsmith explained it to me, the muzzle side taper actually stops about a half inch to an inch short of the muzzle, so the last little bit is original size cylinder bore again.
:front: