doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Altering Chokes

If, in that case, I shoot it would be with the back trigger and the mod barrel. That is what I like about two trigger, differentially choked double guns. I can pick the choke appropriate for the situation.

I have never been able to get off two shots with guns that have barrel selectors. Not so with double triggers. Two triggers, two chokes.

Good points about the ability to make an instant choke selection with a DT gun. I don't think it's of much value for birds like grouse and woodcock, but with open country birds, it can come in very handy. I don't know how often I've done it on pheasants, but plenty of times for sure. On one pheasant hunt, I went straight to the rear trigger on 3 birds in a row. Worked fine on the first 2; missed #3.

Re cylinder patterns: Like anything else, density is a function of shot charge and shot size as well as choke. With something like 7/8 oz 8's, you're only going to put about 250 pellets in the 30" circle at 25 yards, and they'll likely be pretty well distributed. 1 1/4 oz 6's, pretty standard pheasant load, you're probably looking at something under 200 in the circle. But if you were to shoot a 12ga 1 1/8 oz target load of 8's (or worse yet, 8 1/2's or 9's--and I'll use both of those on woodcock, but in lighter loads)--you could well put more pellets in a grouse than you'd like. So you do need to look at the load you're shooting, because depending on your choice, cylinder can still give more density than you want at 25 yards.

Huh???? #9 shot gives more pattern density than #7 shot through a cylinder choke, Larry?? It's a well known fact that larger shot size renders a tighter pattern than small shot. #9 might be more dense due to sheer number of pellets, but won't be as tight as #7. And along these lines, and if what you say is true, then why does RST make #10 shotshells to shoot through your favored cylinder choked guns, at Woodcock?? I buy most of what you have to say, but this one is a hard pill to swallow, at least for me. Plus, at say 15 yards, do you think 5 or six pellets of #9 shot would really tear up the meat of a quail or a woodcock more than say one pellet of #4 shot? I seriously doubt if the more #9's would be as devastating as a single #4 shot, but I must admit, I've never done the experiment, in practice.

This thing has really taken on a life of it's own, hasn't it? It speaks well of the depth and breadth of knowledge and experience here. Two schools of thought are well represented here; the target shooters and the hunters, as well as the folks that do lots of both. My only mild disappointment is that the core of my question really hasn't been addressed: can you change choke effectively by cutting a barrel back? There may not be an answer, as the best answers I've heard so-far were essentially "maybe". I now see why polychokes were so-popular in the 50s and 60s. That in itself might be an answer, as they only "constricted" the shot charge for a very short distance before leaving the muzzle.

Changing from #7 shot to #9 shot will increase the number of pellets in a given weight load by about 200%. Thus if your gun threw a 50% pattern using #9 to get the same density with #7 it'd have to throw Every single one of those little round "BB's" in that 30" circle. You really think it'll do it my friend. Yes going to a smaller size shot increases pattern density even if it has a slightly lower percentage, but that is not an automatic given.
I do not live in prime woodcock country but some years back after a TVA lake was impounded a shift in their flight patterns gave me a few seasons of some shooting. The vast majority of what I killed, along with some wild Bobwhites were taken with a 12ga J P Clabrough having 28" � choked (.010") damascus barrels (Both barrels the same). Load was 1 oz #8's @ about 1150 fps. Shooting was short range, never felt handicapped by being "Over Choked" in any way. I ate them all, none were mangled but they were killed cleanly. The same gun & same load but shot size shifted to #6 was a most excellent cottontail combination when hunting the brush & Briars with a pack of Beagles.
As I said before when folks go to hollering up the advantages of Cylinder bore they virtually always compare it to a full choke.
My personal belief is that modern wads have not really reduced the spread of the pattern to any great extent. What they have done is to eliminate a lot of flyers & put them in the pattern, thus giving that slight increase in density. Haven't done enough pattern counting to be certain, but likely 5% would be more realistic than a 10% increase.
Whether they actually achieved it or not I simply do not know but Lefever advertised 85% patterns with their "Taper Bored" full chokes. Several of their guns which I own & "Presume" to have been bored full choke have only about .030"-.032" constriction. That's about what modern standards are using modern shells.
I said it before & will say it again, A Slight Choke is generally better & far more versatile than either a Full Choke or No Choke.

2-Piper answered your question, Buzz. I'm talking about density, which is raw pellet count, not pattern percentage. Indeed, larger shot will often pattern tighter, all else being equal . . . but with far fewer pellets, assuming the same shot charge.

The problem with looking at patterns from very open chokes is that not many people shoot really short-range patterns, which is what you need to be doing if you're thinking about birds like woodcock. (Remember Steve Smith's average distance to 1st barrel woodcock kills: 13 yards. And if you're going to tell me "Well, just let them get out further!", my guess is you haven't shot very many woodcock. Particularly not early season birds, which are an example of "Shoot when you see them, because if you wait, you won't see them.")

Researching an article on close range shooting a few years back, I shot patterns at 15 yards. I had a 20ga Sauer at the time on which I'd had the chokes opened: Cyl in the right barrel, IC (.007) in the left. Disregarding pellets at the very periphery of the pattern, where a woodcock would've received perhaps only a stray hit if that, the cylinder barrel threw a pattern with a diameter of 22" compared to 18" for the IC. 4 inches doesn't sound like much, until you review your high school geometry and recall the formula for the area of a circle--at which point you'll find that the area of the cylinder pattern is about 50% greater.

If by IC being more versatile you include the possibility of using spreader loads to give you cylinder patterns for very close shooting . . . indeed, IC does have an advantage at longer ranges. The same test included patterns shot through an Ithaca Classic Doubles 20ga, also marked IC--except that one had a constriction of .010, which is on the tight side of IC for a 20. It produced a 14" pattern at 20 yards--and looking at that pattern, shot with 7/8 oz 8's, a centered woodcock would have been pretty badly shot up. Using one of the Polywad discs to make a spreader load: 21" pattern, close to what I got with a standard target load in the Sauer's cylinder barrel.

So there you go, Miller--and that's comparing cylinder to IC.

Somebody help me out here, but at this point I can't get my head around how the total area included in that extra 4" of radius is such a big help. You can't miss a bird on all sides of the pattern at the same time. All you can do is miss at one place on the circumference. You might say, "Yes, but how do you know which side you're going to miss on?". I don't (with the possible exception that the greatest majority of misses with a shotgun are over, and/or behind), but that doesn't change the fact that I cannot utilize that entire area at once to help prevent a miss.

Looks to me like the advantage is the 4" itself, not the total area. How 'bout it Miller?

SRH

Lloyd3, wrote, "can you change choke effectively by cutting a barrel back?"

My answer is yes, to what extent I don't know. There are several elements to pattern distribution. Shot hardness or lack thereof, shot protection or lack thereof, wad configutation, velocity, and forcing cone/choke constriction.
To open up a pattern, especially in a gun made before 1960, I avoid 1-piece plastic shot cups unless they are the spreader type, instead I use card and fiber wads. Soft lead, card and fiber wads will not protect the shot and aid in pattern spread. Shot with high antimony and buffering in a 1-piece plastic wad should tighten patterns.
This thread has continued for 6 pages and I congratulate the forum members for their civility and willingness to give freely of their time and knowledge.

Some light historical reading for the holiday weekend
The Field March 7, 1891 Vol 77:325
"Mr. Griffith on Shot-gun Patterns"
http://books.google.com/books?id=inQCAAAAYAAJ&pg=PA234

Lloyd: the answer is of course yes; less constriction = wider pattern. However, the barrel specialists of the past knew what they were doing with the admittedly inferior 'machine-made' U.S. guns, and the pattern may be deformed or the POI changed. Cut with caution, and get thee to the pattern board thereafter.

And what we could do today with the 2" chunks of barrels littering the floor of turn-of-the-century machine sheds