Jug-Choke Question

[taylorh]

Hi Guys,
A previous discussion brought up the topic of jug-chokes in smoothbores. I think this is a great idea, but I was wondering how it effected roundball accuracy?
Taylor in Texas

 

[roundball]

Hi Guys,
A previous discussion brought up the topic of jug-chokes in smoothbores. I think this is a great idea, but I was wondering how it effected roundball accuracy?
Taylor in Texas

Hasn't affected my .62cal at all

 

[rabjr]

Ooooh you mean I can use the same gun for deer and turkey?? I was thinking I needed two smoothbores.

 

[Russ T Frizzen]

You can't have too many smoothbores! Trust me on this...

 

[Rebel]

Have any of you done any extensive testing to see what effect a jug choke has on shooting rd balls? I would think that the choked part would allow a lot of gas blow by of the shot or allow a patch to come loose from a rd ball. Can you use regular overpowder, fiber cushion, and overshot wads with the jug choke, or do you have to use felt wads that will compress and expand back out. Any info on jug chokes and there effect on shot and rd ball shooting appreciated.

 

[Russ T Frizzen]

No, none of my smoothbores are choked. I enjoy shooting them the original way. It does mean getting a little closer though. My new fowler won't be choked either, but it is a 10 gauge and can throw a heavier shot charge. When I have tow I use that and I have used shredded cotton batting to good advantage. A little beeswax/olive oil lube on the wadding works well. I never take a shot past 25 or 30 yards, anyway.

 

[MSW]

psst- hey swamprat... what rus t said- you really can't be too rich, too thin, or have too many smoothbores (so long as they're flinters) ...

now, about that second mortgage...

 

[Flintandsteel]

Rus T,

Wouldn't let tradition hold you back on this one. Jug choking has been around for a couple of hundred years. Not really an issue to take a stand on, like plastic stocks, percussion locks, in lines, etc.

 

[CoyoteJoe]

Rebel, I can't give you specific results as I was mainly thinking of my smoothbore as a bird gun and have done only a little work with ball. However, it was my impression that my .560" Jack Garner barrel grouped around 3" at 50 yards before the jug and more like 6" after. I only fired one group before and that 3" may have been a fluke, so I can't say for sure that the jug hurt roundball performance but I do think so.
I can say for sure that the jug improved my shot pattern from about 50% at 25 yards to 50% at 40 yards and that is what I was after. I have rifles for shooting ball and my only use for ball in the smoothbore would be the occasional smoothbore match, of which there are few in my part of the country.
It would be interesting to see a comprehensive "before and after" test of round ball accuracy from jug chokes.

 

[roundball]

No, none of my smoothbores are choked. I enjoy shooting them the original way.

FYI...Jug Choking is not a modern thing...it's part of the past...the bad news is there are fewer and fewer gunsmiths who have the knowledge and the machine shop equipment to do it.

 

[CoyoteJoe]

Rus T,

Wouldn't let tradition hold you back on this one. Jug choking has been around for a couple of hundred years.

I have my doubts about "couple of hundred years", I'm thinking 1870's, breechloading guns. W.W. Greener did much to perfect choke boring in the last quarter of the ninteenth century. There may have been earlier examples but the process was surely not well known that long ago.

 

[taylorh]

How exactly is jug choking done? I mean, is the enlarged portion of the barrel larger or smaller for full choke vs. cylinder?
Taylor in Texas

 

[roundball]

How exactly is jug choking done? I mean, is the enlarged portion of the barrel larger or smaller for full choke vs. cylinder?
Taylor in Texas

Larger...the more choke that you want, the larger the diameter of the "expansion chamber"...I asked for full choke so mine was enlarged about .030" bigger than cylinder bore in the expansion chamber, then step tapered back down to cylinder size an inch before muzzle exit.

He explained to me that when the shot column hits the expansion chamber, the shot around the outside of the shot charge expands and momentarily slows down, allowing the central body of the shot to continue on forward then the 'slower' shot gets forced back down to cylinder size, towards the tail end of the shot column.

For the world it sounded to me like it makes a longer shot column which accounts for a more dense pattern at distance...what I do know is, that whatever the physics involved, it sure works.

 

[montanadan]

Roundball-I was curious too.Thanks for the explanation..Respectfully montanadan

 

[musketman]

How exactly is jug choking done? I mean, is the enlarged portion of the barrel larger or smaller for full choke vs. cylinder?
Taylor in Texas

Here is a graphic to help explain where the jug choke is cut into the barrel...

 

[paulvallandigham]

While the expansion does re-sort the outer shot to a brief extent, it is the squeezing of the shot column at the forward portion of the "jug " that causes the shot to stay together when it leaves the barrel, just like normal choking in a modern gun would do. The column of shot is not going to lengthen to any real extent in the brief time it passes the jug choke area. Remember, it is being pushed by gases at the back, and any relaxation of friction on the shot will simply cause a acceleration of the shot column. The shot is also blocked for much forward movement by that overshot card, and the air it is pushing in front of it as the whole package goes down the barrel. If anything, the column tends to expand and shorten as it passes through the jug, only to be constricted and lengthened by the front end of the jug choke as it leaves the jug. It is that final squeezing that allows this kind of choke to be as effective as modern chokes.

 

Consider this. Looking at the graphic presented by musketman, picture the shot charge 3/4 of the way along the expansion chamber just before it reaches the constriction. At this position, for all intents and purposes, the shot is being fired from a barrel of this bore diameter. The fact that it spent most of it's travel time in a smaller bore is no longer relevent. Now, it goes through a choke just like any other shotgun choke. A chokes function is not to make the bore smaller. If that were the case, a 20g cyl bore would shoot a tighter pattern than a 12g cyl bore. The choke redirects the outer portion of the shot charge. Rather that leaving the bore in a straight line as in a cyl bore, where the pellets immediatly start to fly off in different directions, the choke changes the direction of the outer pellets so that they leave the bore in a convergent direction flying into the center of the shot cloud which holds the shot charge together longer. Jug choke does the same thing.

Cody

 

[Rebel]

Ok, but what effect does it have on shooting rd balls?

 

[paulvallandigham]

None. You will have gase escape around the PRB if you do not use an overpowder wad( and even with it, depending on the length of the Jug), but a jug choke is so small it should have no effect on the accuracy of shooting your PRB.

 

To my way of thinking it SHOULD make accuracy erratic at best with a RB. I have no experience with RB in a jug. However, I have talked with several people that HAVE that experience and they all concur with Paul, seems to have no ill effects :shocked2: . Go figure. Don't know WHY but, who cares, ya gotta luv it :grin:

Cody