Jug-Choke Question

[paulvallandigham]

Remember that that PRB is traveling across that jug choke at anywhere from 900 to 1300 feet per second, and even if the jug is 3 inches long, that means the PRB will cover that distance in a very short time- faster than you can even think to blink an eye. :hmm:

 

[CoyoteJoe]

Remember that that PRB is traveling across that jug choke at anywhere from 900 to 1300 feet per second, and even if the jug is 3 inches long, that means the PRB will cover that distance in a very short time- faster than you can even think to blink an eye. :hmm:

Maybe so, but I've seen many rifle barrels with just a very short segment where the bore is enlarged by just a couple of thousandths, just a slight "loose spot" and such barrels never produce very good accuracy.

 

[paulvallandigham]

I would not want this situation in a rifle. We are instead talking about a smoothbore, without rifling, and good accuracy is a 2-3" group at 50 yds. Please do not mix apples and oranges. There are separate and valid reasons why you don't want any kind of jug choke in a rifle, where it works fine for firing shot, and the large PRB we shoot in smoothbores, for the ranges we use these firearms to hunt deer. Paul

 

[Rebel]

Ok, but how about the wads? Can you still use the same Heavy overpowder wad, fiber cushion, and thin overshot card wads? Don't you get gas blowby of the shot or rd ball in the jug section?

 

[paulvallandigham]

If ou were to load enough cushion wads to span the jug choke, the PRB would be past the jug before the wads enter it, and any gas would be blocked by the wadding behind that PRB. The filler cushion wads I would try would be dry, or very lightly lubed, with only one cushion wad being fully lubed to grease the barrel to soften fouling. Again, you would want to know how long the jug choke is in a particular gun, and then choose your fillers/wads according when shooting a PRB.

 

[Rebel]

I sure would hate to have to use 2"-3" of cushion wads for each rd ball shot. And what about with shot, wouldn't there be gas blow by with it too without a long Wad column?

 

[Java Man]

I would think you would be at full velocity, and any blowby through the choke section would'nt matter much. IMHO.

 

[paulvallandigham]

obviously, jug choke does not affect shot patterns, even if there is some gas blow by. The patterns speak for themselves. Again, you are shooting different projectiles- one a round ball, and the other shot- so there are different rules. The wads used under a load of shot are deep enough in comparison to the length of the jug choke that any gas that comes around the wads are pretty much cut off by the wads entering the restriction at the front of the choke. The shot will have already entered the forward portion of the barrel in front of the choke, so the gases would not affect them.

One second comment about shooting PRB in a jug choke smoothbore. This may be one time when using a ( over shot ) card wad on top of the PRB ball may make sense, in this regard: I would want a smooth hard surface to be pushing that column of air in the barrel ahead of the PRB so that there is a partial vacuum created behind it, and around that PRB in the barrel. The partial vacuum will allow the PRB to travel through the jug choke without the force of the air in front of the ball pushing on the edges of the patching to make the patch slide off, or behind the ball while its in the jug choke. I haven't test this, as i don't curently have a gun with a jug choke, but it makes sense based on everything I understand about ballistics. The reason modern shotcups have petals cut into them is so that the resistance of the air in front of the shotcup will force those petal open, creating an air brake, and separating the plastic wad from the shot almost as soon as the wad leaves the muzzle of the gun. This is why paper shot cups don't seem to work without cuts being made in them to create the same kind of petals as found on plastic cups.

 

[Rebel]

Ok that kinda makes sense. I still wish there was someone here that had done some extensive testing of the effect of a jug choke on shooting a rd ball. And i still don't know if people use the same wads as in a straight bored gun.

 

[roundball]

Ok that kinda makes sense. I still wish there was someone here that had done some extensive testing of the effect of a jug choke on shooting a rd ball. And i still don't know if people use the same wads as in a straight bored gun.

I didn't do any EXTENSIVE testing but what little testing I did I simply used the same basic load configuration I normally use in[url] rifles...in[/url] this case it was 80grns Goex 2F, one .62cal Oxyoke wonderwad, .015" Oxyoke prelubed cotton patch, and Rush Creek .595's...holes cutting each other at 25yds just shooting sitting in a chair...jug chokes aren't new...they've been around forever and if there was a problem shooting PRBs out of them I'm pretty sure it would be well known by now.

 

[Rebel]

Bill, i know but i am wondering if i use the same thick overpowder card wad, fiber cushion wad and overshot card if they will seal the bore right or if i need to go to the wool Wonder Wads. I guesss like you said, they have been around a long time, a lot longer than the Wonder Wads have, so maybe the regular wads will work fine.Thanks for the load info. Take care.

 

[paulvallandigham]

Rebel: If you hve ever loaded a 12 gauge brass casing shell, or seen any material on the old brass casing black powder large bore cartridge guns, as used in Africa, like the 600 nitro, you wil find both use from 2-3 inches of wads as filler under the round ball they shoot. The use of multiple cushion wads in 12 gauge hulls was also common up until we got plastic shotcups in the 1960s. If you can find some old paper shells, cut one open, and take a look.

I agree that it would be a pain in the neck, but it does work.

Paul

 

[Rebel]

Thanks for the info Paul I may have to give it a try if i decide to have my smoothbore jug choked. If i can't work up a better turkey killing pattern past 20 yds i may just have it done.