doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Adding a fixed choke to an English gun

Look at enough doubles you come to the conclusion there are a lot of poor choke alterations. Thin at the muzzle out of round rough etc. Nice SxS tweaking patterns with loads is a better solution.

Boats

No argument there, buzz, with the caveat that density PLUS pellet energy, is what kills. I have stated that myself here many times. But, box birds is almost unique in the shotgunning world. It is the about only time where we want to kill dead at any cost, that cost being an inedible bird. We aren't going to be eating the nasty things anyway, eh? Aside from box birds, card shooting, and turkey hunting, distance is THE reason for tighter chokes.

One way of looking at it is this: At what distance does a full choke pattern equal the aforementioned cylinder pattern at the 30 yards mentioned? I think cylinder at 30 yards is stretching things a bit, myself. I'd prefer IC there. But, if you think that a cylinder pattern is adequate at thirty yards, pattern that cylinder at thirty yards and then put in the full and keep backing up until you get to the distance that the patterns are roughly equal in density and diameter. I think it will surprise you.

All my best, SRH

To add to what Stan just said also don't forget that as you back up to find the distance where you get the same pattern count you are also losing pellet energy. You will thus not have an equal killing power as with the shorter range of the more open choke.
I totally agree with what tan said, just wanted to add this little caveat.

I think we are all on the same page here, with the exception of Larry Brown of course, who is deeply in love with cylinder bore ;-)).

According to "The Mysteries of Shotgun Patterns" by Oberfell and Thompson, their best estimates of the effectiveness of choke are the following:



They continue, "It is interesting to note two unique properties of the table; (1) within normal hunting range, 20 to 50 yards, an increase of 5 yards decreases efficiency by approximately 10 percentage points for the same choke, and (2) an increase of 5 yards requires changing to the next higher choke to prevent a loss in pattern efficiency. Thus, a rule of thumb based on the above data will make it easy for the shooter to make ready comparisons of pattern efficiencies at various practical distances. The rule is:

"Allow an increase or decrease of 10 percentage points for a corresponding decrease or increase of each 5 yards." Here is the table for this rule:



Now for my personal opinion (and only mine)--I have observed that by far the majority of my shots fall no farther than 25 or 30 yards maximum and I'd say a good mean avierage would be closer to 20. And that is on all upland birds. Of course there are the infrequent opportunities over that but I'd much rather be prepared for 90% of the shots than the rare 10%. Overhead shots are really interesting. A bird 30 yards overhead (90 feet) appears to be a distant speck and often a shooter hesitates to attempt it while gleefully blasting away if the bird is the same distance on a horizontal plane. It's an optical illusion, same as the moon appearing to be much larger when rising than when overhead. The same illusion applies to perceived lead. A 30 yard overhead shot might appear to need a lead of at least a boxcar length while a horizontal bird same distance might appear to only need about six feet. I think the reason for this is our binocular vision which allows us to quickly and accurately judge distances requires other fixed objects in our vision. Overhead objects lack this and we only have the single bird in view and our vision becomes for all practical purposes monocular, lacking depth perception.

Using the above tables an argument could be made that supports the use of a tight choke for all shooting conditions since a killing pattern could be delivered over a much longer range of distances. I have known some exceptional shots who use full on skeet very successfully. I am not one of those. My shot placement is not nearly as precise as theirs and I lack the coordination to perform to their level. Much of my shooting is in a much less formal field setting where the birds are rising unexpectantly, at random distances, and flying at trying angles often with all sorts of obstacles interfering. And often time does not allow me to untangle myself and take a proper stance. So my shots seldom center the bird and I need all the help I can get from a more open choke to bag my bird.

Interesting discussion.

Joe; Are the pattern percentages in the tables above, at the given distance, calculated based on pellet count inside a 30 inch diameter circle?

I just can't put much faith in that table, Joe. I know O and T are highly respected, but something just does not seem right about it. Look at the full choke in the tables. If the pattern is degrading as they say, at 100 yards there would be a "0" there, or under 10 % at best. Now, if that were so, how do we explain extreme long distance shooting as done by Digweed and others? We know he uses big shot, like 5s, but you still have to hit a pigeon or crow with several pellets to down it. He kills at those distances consistently. I kill doves with an IM at 60+ yards consistently. On two consecutive shoots a couple months ago I killed 6 straight crossers at 60-70 yards. Not where they fell, necessarily, but where they were hit. What are the odds of that happening with a 25% pattern?

Doesn't add up.

SRH

Yes, Buzz, they used a 30" circle at all distances.

Thx Joe. At longer distance I'm wondering if larger shot (say #2 vs #9) would change those percentages? I'm thinking likely so.

Shot Pattern Spread from Field and Stream Sept 1964. I do not have the original article but assume the shells were Winchester/Western Mark 5 with the polyethylene shot collar introduced in 1961. Modern loads are likely better.


����������������YARDS����������.
.....��.....10�� 15��20��25��30��35��40
CHOKE
Full����. 9��..12��16��21��26��33��40 inches

Mod��..��12��.16��20��26��32��38��46 inches

Imp Cyl��..15��.20��26��32��38��44��51 inches

Cylinder��. 19��26��32��38��44��51��57 inches