doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Choke Modification Methodology ?

Interesting about the shot used on top of the insert, I haven't tried that. As well as the insert modification. What type of modification?

I usually put a Spreader in the right barrel when hunting over my dogs. From what I've read, they don't widen the actual pattern, but disperse the shot throughout the pattern earlier, "Spreading" out the shot stream.

Anyone pattern any loads with these modifications?

Regards
Ken

These types of chokes were cut with special made reamers. Anything is possible today with modern technology. You could have a reamer made to any shape you desire. Because of the limited usefulness of such a tool it would not be cost effective unless you planned on cutting a bunch of chokes to this particular shape. A whole bunch of work and cost for very little gained over a choke with a parallel section in my view.

Off the original topic but.

I load Polywad spreader disk for 4 gauges all used in tight choked SxS guns. Round Disk with the post bottom goes on top of the shot. Patterns are OK at 20 yards fall apart after, how far past 20 depends on the shot size and load. Anyhow 20 is a good working limit

Way I use them on Clays courses is if scores are being recorded and the target is crazy close like most Rabbits or in your face incomers 2nd of a pair put the spreader in one or both barrels. Show pair targets closer than skeet distance is the test. If no score card I shoot the whole course with tight chokes. I would rather miss clean in fun rounds than break with light strikes edge of the pattern using the spreader shell.

Hunting I have a Spaniel and he flushes out dozen yards or so. Modified choke is fine when using light shot loads like 3/4 or 7/8. I just patterned one of my 16's at 25 yards and 3/4 oz of 7 1/2 modified Choke. It's a perfect Game pattern to my eye.

Exception dog training with Quail in traps right at your feet. Then the spreader works well. Have never hunted Grouse, Guys I know that do mostly use Light Auto shotguns with real short barrels and no choke at all. Not sure you can make a 28 or 30 inch tight choked SxS do as well as the 24-26 inch Cylinder choked guns using a spreader in the long gun. Probably not.

I don't expect any more of spreader loads. Targets under 20 yards. Lot of potential 25 even 30 yard targets better to buy a open choked SXS gun. Spreader in a long barrel is not going to serve very well

Boats

if the out side is hand filed to match the bore of a barrel set when it was mfg.if you cut the choke and guide off the bore then it would stay concentric to the bore and since the out side was hand files to not show an eccentric bore to the exterior profile.

No one has, as of now, found a choke profile that performs differently than a true conic of same entry and exit diameters. The reason is that the shot is behaving as a fluid and accelerates as it encounters the constriction. The shot does not "slam" into the constriction; it is an orderly flow. A profile that "eases" the shot into the constriction has little, if any at all, effect on the shot column. I realize that this is counter-intuitive and this is the reason so much effort has been wasted on "magic" chokes.

DDA

No shotgun will ever deliver an "even" pattern. "Even" meaning pegboard layout patterns. All patterns are Rayleigh distributions (OK to think of them as Normal distributions). A cylinder pattern is identical to a full other than the cylinder blooms quicker and, likewise, withers quicker. If you captured a cylinder pattern at 60 yards, you would find it is still a Rayleigh distribution of the shot. Further, you would find that those few pieces of shot that were in the center at 20 yards would still be there at 60 yards. This is why those who have extra small aiming error can make breaks at distances where the pattern is clearly too large to be effective. They would probably have similar results with a .22 rifle.

DDA

Rocketman has a point.

Journee, Lowry. Jones, have shown via repeatable experiments that patterns follow predicable distribution.

A writer in Gun Digest wrote an article "Heat and Beat It" re the effect of crude swaged choke compared to more sophisticated types. There was no difference.

Journee also found that training lessens pointing errors, and that presumably would improve scores. Again, confirmed by later experiments by Dr Jones.

It took about 100 years to verify that shooting technique is the vital bit.

"Even" may have been a bad choice of words . . . although Mr. Brister used it in his book, with additional clarification:

"In the thousands of patterns tested by Oberfell and Thompson for their "Mysteries of Shotgun Patterns", the point is made repeatedly that the pure-cylinder choke (no choke at all) throws the most even patterns of all. That is, in layman language, the patterns have fewer patches or holes relative to the spread of the load." He goes on to mention Russian Olympic skeet shooter Eugene Petrov, who was the first person to shoot 200 straight at international skeet, with a gun that essentially had a blunderbuss-like muzzle.

Ken, Jay Menefee down at Polywad shows photos of the spreader discs with holes punched in them. I experimented with a one-hole paper punch, cutting out 3 little semicircles around the periphery of the disc. Tried that vs unaltered discs vs discs one size smaller (20ga in a 16ga reload, for example). Found that my modified discs gave me the best spread while eliminating the weak center. Mike Campbell is one who's used the layer of shot on top of the disc and can tell you more about that.

That's interesting. I have a couple of 2 7/8 inch 10 G Doubles. Called Polywad and found they don't make a 10 G spreader disk but recommended using a 12 G disk instead

Patterns with the 12 Disk in a 2 7/8 inch 10 G shell may be the best spreader patterns I have seen. Of course it helps when they throw 1 1/4 oz of shot. The guns are choked very tight and the disk helps a lot on Rabbit targets. At least I think so which is half the battle.

Boats