doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com jug choke

Once again the phrase "jug choked" has reared it's ugly head. I am convinced that the term is used instead of "out of proof" when the bores of a vintage gun are beyond proof and since they are widened increase the difference between bore and muzzle Wouyld someone please take the time to educate me on this matter

justin: jug choking has to do with choking a cylinder bore shotgun barrel. the process consists of removing a few thousands of metal from the bore an inch or so back from the muzzle. this creates an expansion chamber for the shot column to pass through. after expansion, the shot pattern is compressed back to the original cylinder bore diameter. this process results in a tightening of the shot pattern. usually, one can expect improved cylinder patterns out of a cylinder bore gun.

thanks ed,boy did I have that screwed up

While what Ed said is correct this is not the limit of what has been done. Bbls having a mild choke have been "Jugged" in order to give them an increase of choke. The process is essentially as Ed described, just it is not an absolutele requirement to start with a Cyl bore.
Proofing (British) measured the bore dia at a point 9 inches from the breech, jug chhoking was all ahead of this thus did not affect the proof of the gun.

what 2-piper says re jug choking makes logical sense. however, i have no experience with jug choked guns, except those with cylinder bore. if you jug choked a barrel with an existing modified choke, would that give you full patterns?

I believe Winchester WS-1 choke seen in Model 12, Model 21 and other Winchester shotguns is a jug choke.

I've jug choked a few guns with good results. In fact I believe that a true cylinder barrel can be made into an improved cylinder and more importantly can be made to shoot a nicer pattern with fewer flyers. You only need to remove about .003" giving an increase in diameter of .006" just behind the muzzle. Easy to see what you are doing and get a nice polished little jug. Much better than a plain cylinder.
nial

Jug choking also gets used in muzzle-loading guns because it is easy (or possible) to load through a jugged choke. It may, or may not, have been developed before the muzzle-loading era declined. It's the same process described above. It's not unusual for people who shoot reproduction fowlers to have them jug choked. Because such guns are generally made with barrel-wall thickness that greatly exceeds that of the British doubles discussed on this board, they can sometimes be jugged to full choke for turkey hunting.

There was also a period where guns were converted to cartridge, and the cylinder bores could be jugged to achieve some choke on the converted barrels.

very interesting. never thought of that.

Winchester performed patterning experiments comparing their jug choke, WS1 to true cylinder and at 20 yards in a 30 inch circle found with cylinder 76 pct of shot was within the circle and with WS1 at 20 yards 87 pct of shot was within the circle. However, at 40 yards the cylinder produced 35 pct of the shot within the 30 inch circle whereas WS1 or the jug choke oddly enough performed worse at 40 yds with only 33 pct of the shot within the 30 inch circle at that greater yardage. This info is from Schwing, Winchesters Finest, The Model 21.