How common are jug-choked shotguns? I always thought that a jug choke was only used when some choke was to be put in a gun that was already cylinder bored as when the barrels were cut back.
I was reading a letter to the editor in "Forest and Stream" 1889 which seems to indicate that jug-choking or as they called it "Recess-bore was common.
This may be of interest;
"Recessed-bored Shotguns

Editor Forest and Stream:
In the "Forest and Stream" for July 25 and Aug. 1, (1889) are the published results of a gun trial that you kindly had made on your range. As the recess system of boring is apparently but little understood in this country, Perhaps you will allow me a little space to describe its advantages. It is not really a choke, but an enlargement of the barrel, commencing about 2in. from the muzzle and extending toward the breech for from 2 to 4in., the last 2in. of the barrel being practically of the same diameter as that part on the breech side of the recess; there is, therefore, no obstruction to the passage of a ball. Without reference to the use of the latter, some English gun makers adopt the recess method of boring in all their guns, and obtain with it as close a shot pattern as with more common form of choke. It is much used by sportsmen for jungle shooting in India where game can only be seen at close range, at which the effect of a 12-gauge round ball is found to be quite as deadly as that of a .45 or .50 express bullet......."

How common was this? Has anyone found many English guns choked this way?
Pete

I have one Pete. It is a C. F. Leader hammer gun with laminated barrels. I think it is from Birmingham around 1875. I assumed jug choking was done prior to modern choking but I now see there is a dual function to jug choking allowing a round ball to pass through for larger game while having choke for sporting clays (just kidding).

I have not shot it for years and I am pretty sure it is in the back of the safe so a pain to get to but I think it is marked "not for ball" which now makes no sense to me.

If it is, as you remember, marked "Not for ball" It is strange. Why would they make a gun with a recessed choke and then mark it "not for ball"?
Maybe the gun was originally cylinder bored and then, to give it a little more range, jug-choked later.

Pete

Burrard speaks of this method being used when someone had ordered a gun to produce a given pattern with a given load. This allowed the gunmaker to increase the pellet count without "Backboring, which would often cause the gun to need Re-proof. The way he spoke it was a fairly common practice among "Bespoke" guns.

I wonder how common it would have been to make a gun with a recessed choke just to make it more versatile? To be able to use it for ball or shot. The letter in Field and stream seemed to say it was very common.
Pete

Maybe builder's gun had longer barrels marked "not for ball", and later shortened; then recessed choked to improve patterns.

That'd be my bet...Geo

I jug choked a muzzleloading trap gun I made 40 years ago. It's still easy to load it and yet get the choke you want. I have also more recently done it to a couple of my SxS's.

How did you do it Paul?

So we know what type of gun:


This is a beautiful gun in great condition. I measured the jug chokes. Both chokes start tapering essentially at the muzzles reaching their zenith at about 1 1/4" and returning to bore size at about 4 1/2" from the muzzle. The taper is gentle at the rear and more abrupt as it heads toward the muzzle. The left increases in diameter by about .030 while the right about .038"

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 ¼ choke all the way up to full. An I/C choke would not normally have required it. A ¼ 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.

Yes, fragile is a big issue for me, too, terc. I misunderstood what you meant by "safe".

I've repaired dents myself, and it's a slow, tedious job the way I do it.

SRH

Reamers that I am familiar with are all cylindrical ground on the sides, cutting only on the tapered portion. This includes expansion or adjustable reamers I am familiar with. Did you have to back off the flutes on the side to get the reamer to cut in this manner. It would take extra ordinary force to get a normal reamer to cut on the sides as they are intentionally made not to. This would b quite apt to bulge the barrel in this thin area.

2-piper, I'm not sure what you're talking about. I use adjustable reamers that a fellow gave me or ones I buy from Brownells. They would have to cut on the front edge where it's sharp. If you're jug choking a barrel with no choke, then what you measure at the end is what the barrel in back 6 or 8". If it's .050 thick at the muzzles and it only has a IC choke, or .015 constriction, then the walls farther back are .035. If .005 on a side was removed it would be .010 more, or now a IMP/Mod. I'm not saying any barrel can be jug choked. It's up to each owner to decide if it's possible. But as said, there's not a whole lot of pressure left and you aren't gonna blow the barrels. Maybe dent them, but I'm still shooting the ones I did with no problems.

Paul;
Yes whether a barrel can be jug choked is dependent entirely on how much wall one has to work with & how much you desire to enlarge it. I was not speaking of this.

What I was speaking of was the operation of the reamer itself. Perhaps I did not understand exactly what you were saying. Just as a standard drill bit cuts on the end & not on the sides like an End Mill a reamer is sharpened to cut on the taper. The straight portion of the reamer body is ground cylindrical so as to Not Further Enlarge the hole in reaming.

What I understood you to say was that you placed the reamer in the bore & expanded it out tight against the walls which would mean it had to cut on the portion which was designed NOT to cut. To use an expansion reamer efficiently in this manner the lands on the flutes along its body length would need to be backed off to give relief for it to cut properly. Failure to do this would put extreme pressure on the inside of the bore & due to the thinness in this area could indeed result in the bore being bulged rather than metal being removed by cutting.

I put in over 35 years in machine shops, as a machinist, & have never seen a reamer designed to cut in this manner without modification. I have a set of Brownell's Choke Reamers & this includes them.

I fully agree with your statement "They would have to cut on the front edge where it's sharp". The way I was understanding your original ;ost on this though it sounded as if you were not using the Front Edge, but rather the portion behind that edge where it is not sharp. That was what I wanted clarification on.