doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Jug choked shotguns

It looks to me that the barrels were not cut but who knows. Not for ball suggests normal chokes. It is possible someone removed them and a later owner jug choked it.

As I recall "Not for Ball" during the era in which this stamp was used was required on any barrel with at least .008" of choke constriction. This gun likely had less than full choke & then was jugged to give a tighter pattern. Could have been done when built or at a later date either, hard to tell. With the Not for Ball stamp it would have had at least that .008" of choke when proofed. From the picture it certainly does not appear to have been cut.

"Normal" choke with the Not for Ball stamp could have been anything from around a � choke all the way up to full. An I/C choke would not normally have required it. A � choke of around .008" to .010" was quite popular for driven shoots in England.

"IF" it shoots good, enjoy it & don't be overly concerned about it.

PS; 13 = .710" & 14 = .693 or a difference of .017". The difference could however have been less than that even. The bore could have just "Barely" accepted the 13 gauge plug & the choke accepted the 14 gauge plug with more liberal clearance. Too often we look at these early markings & take them as "Exact" measurements, but my understanding is they were not. The Proofers simply had a set of plug gages & the bore & chokes were stamped with the largest one which would enter to the required depth. The bore gage as I recall had to enter to a depth of 9". I have not seen data for the choke gage, but assume it just had to enter the muzzle.

The present bore size is 0.720 to .722 depending on which tube. The barrels sure do not look cut. One thought is it was honed a bit losing the choke and the jug choke put it back.

Builder, an adjustable reamer that adjusts from the end with a screw is welded to a 3/8 or 1/2 steel rod about three foot long with a tee handle on the other end. Another rod was drilled and slotted on the end so I could reach in and adjust the reamer while it's in the barrel. Years ago V.M. Starr wrote a little book about jug choking barrels and said it should be done 2 to 8" back, or for a 6" area. This allows the shot time to open up before it gets squeezed back down. The reamer is put in the proper place, and opened up a thousand or two. You're trying to open it while it's against the barrel. Then it's twisted and pulled back and forth for 6". Maybe tighten it once or twice, then loosen it and remove it to clean it from shavings. Do it all over till you get what you want. I usually wipe the barrel clean after a time or two and check it with a dial indicator. When done a barrel " ball hone " is used to smooth things up and finally some steel wool on a barrel brush. Hope this helps. Paul

Thanks Paul. Yes, your explanation makes sense to me. Sure is a lot of work to accomplish.

I can't imagine jug choking being safe in most barrels. The area needing to "jugged" is usually already the thinnest part of the barrel. Barrel wall thickness near the muzzle is often only .020 to .025 . Even trying to make a cylinder choke into an Improved cylinder choke would make the barrel ends very fragile.

.020 to .025 ? What kind of American iron are you shooting ? All my Remingtons, Lefevers, and Parkers are much thicker than that - closer to .060. If yours are .020 you're right , don't do it. But if they're closer to .040 or thicker, it only takes .005 on a side to equal .010 choke and that's a IC. LM would be .015 or .0075 on a side. It doesn't take all that much to make an improvement. I have 10 Remingtons, 2 Lefevers, and 3 Parkers, all of them with close to .060 wall at the muzzle. I wouldn't think pressures are more than a 1000psi or so after 30".

Paul, I'm not trying to start an argument but I think you are measuring wall thickness at the end of the muzzle. The wall thickness would be the thickest at that point. A jug choke would be reamed 3 to 6 inches back from the muzzle. It is hard to find Parker or Fox guns with .030 wall thickness at that point let alone .060.

If you can show me an example of a shotgun barrel that has bulged or burst near the muzzle, that was not because of an obstruction, I might agree with you. But, you won't, because you can't. The pressures are so low by the time they reach 6"-8" from the muzzle that the only concern with thin barrel walls there is denting. If a "normal" barrel is going to burst or bulge, because of high pressure, aside from an obstruction, it is going to be in or near the chamber, not 6"-8" from the muzzle.

SRH

Stan, I didn't say bulge or burst. I said fragile. Thin barrels do dent easily , we've all seen that. A dent in the forward part of the barrel is an obstruction. Couldn't that cause a bulge or burst.
I recently looked at a nice Fox 20g shotgun. The choke area was riveled . I don't know what caused it, they were pretty thin though.