doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Forcing cones in old doubles

Larry;
I did not say that he said they balanced one another. Since a 12ga & a 28ga have different bore sizes it should be entirely obvious they don't. What he did say was they used the same criteria, ie they both balanced the wt & column lenth to their bore dias. Again that is not the case, the shot charge of the 28 is slightly heavier than the 12's in proportion to its bore & the column length is not even playing in the same park in that relation.
1�oz of shot in a nominal 12ga bore, not taking up any space for a shotcup etc, just the bare bore, will have a column length about 18% longer than the bore dia. To maintain the same "Relation" to the bore then the 28 ga would need to also be approx 18% longer than its bore. BUT 3/4oz in the 28ga has a column length, all the same criteria, of about 65% longer than its bore.
To the best of my knowledge no ammo makers have ever attempted to load shells bearing an equivelent ratio of the column length to the bore dia. They do in fact load with the idea of balancing the shot load to the charge wt & burning speed of the selected powder. This is of course done for all wts of shot in all gauges, heavier wts in a given gauge requiring slower powders. When the shot column is balanced to the powder type used then the column length will end up being very nearly the same length for any gauge, when using the same powder. (Ever wonder why normal shells are virtually all close to the same length regardless of gauge), they carried shot loads which were very similar in proportion to their bore. This does apply "Equally" to all the gauges (remember the .410 is not a gauge so is ignored here) there is no Magic or Mystery involved that puts the 3/4oz 28 or the 1 1/4oz 12 in a different catagory than say 7/8oz in a 20 or 1oz in a 16. They all have virtually identical, within a small range, of balance of shot wt in relation to bore. Column length in relation bore of course gets progressively longer as the size of the hole goes down. This is cited as an advantage by some & a disadvantage by others. I really doubt that except in extreme cases, as the 3" .410 it is of much significance as long as the proper powder for the load is selected.
A well bored gun throwing good patterns of about 75% at 40 yds wouuld be expected to produce 95%+ at 35yds. With the target moving at 40mph that 6% reduction would be about normal, a good load certainly but not something which can't be equaled by any gauge with a good load. No Mystery here just a good gun with a good load shooting "Just Like its Supposed to".

Indeed, you didn't say that HE said they balanced one another. Rather, you stated: "If these two loads balance one another . . . " Since you recognize they obviously don't balance one another, why would you make that statement in the first place . . . other than to imply that's what Brister's sentence meant? Looks to me like you were twisting his words, and you're now trying to twist your own to get out of your original twisting. (Where's Chubby Checker when we need him?)

And on your expectations for what a gun will do at various distances, you're starting at 75%, which is already beyond full at 40 yards--and really good for that poor little 28ga, because it's supposed to deform more shot than a larger bore. Black's Wing and Clay, listing full at the standard 70%, suggests an 84% pattern at 35 yards--and that's at a stationary target. And since most people (other than Brister) haven't shot patterns moving at 40 yards, I don't think we can say anything is "normal"--except that I think a 90% pattern at that range, with string in the equation, is a result I think one might have trouble duplicating on a very consistent basis. But I guess we won't know that until we repeat Brister's experiments with moving pattern sheets. And my wife has already told me there's no way she's going to drive the pickup with me shooting.

Well now Larry I am quite knowledgable of the fact that 70% patterns have been considered full choke performance for well over 100 yrs. Yet we say that shells have improved over the years. I read all the time about people claiming they have guns which using modern loads pattern 90%. It is quite obvious a shot which patterned 89% on a moving target at 35yds would have had a stationary pattern at 40 well in excess of 70%. It should also be well noted that to produce such a pattern not only requires an above 70% pattern, but also indicates a load producing a very high rate of central core thickening. For any use that I would desire to use a 28 I would find this more a - than a +, but then that's just me.
As to the wording, well I was a machinist, not a writer, I do believe though you well understood that I was simply using Bob's statement that they were both balanced relative to their bores. Bear in mind the word balance indicates a comparsion to Something. His own statement was that it was "Their Bores". I adequately explained why they were not.
"IF" I had the financial means Larry, I would equip the trailer, haul it to Iowa, buy a sufficient quanity of what ever brand of 3/4oz 28 ga loads you desired. I would then personally drive the tow truck while you did the shooting. I am quite positive we would very quickly establish that was not typical performance for the load.
The "ART" in this would be placing the shot effectively on the moving board. The Science would be the % of shot within the 30" circle. I do have the intelligence to distinguish meaning of the two words. If there is some factor of ART which applies to the ballistics of a shotgun please do inform me of it.

Miller, I doubt we'll resolve this one, because you're moving faster than Brister's moving targets. You now go back to the loads being balanced to "their bores", which is VERY different that your "balance one another" phrase, which apparently is now somewhere distant in your rearview mirror (where it belongs). The previous sentence in Brister's book holds the key: whatever the mathematical relation between the length and weight of shot column relative to bore diameter (and other factors), the result is "highly efficient for the shot load it throws". In other words, balanced in terms of the patterns they deliver.

And you're now doing backwards math. I agree that a load which patterns 89% at 35 yards is almost certainly going to pattern better than 70% at 40 yards. So, let's follow the logic on that one and arrive at what it means: That particular choke and load is highly efficient; more efficient than your average full choke, regardless of gauge or load, since the standard for full choke at 40 yards is only 70%. So, in essence, you've come round to agreeing with Brister that, in fact, the 28 is indeed "highly efficient for the shot load it throws"--because otherwise it would not produce patterns like that. Particularly when it has to deal with more potential shot deformation (coming out of that skinny little bore) than do the larger gauges, all else being equal.

The art of the whole thing is that some loads in some gauges, for whatever reason--likely having nothing at all to do with a "balanced" load, or a "square" load--simply perform better than one would expect them to, going purely on mathematics and theory. it's a bit like choke in that regard. Squeeze the barrel a little, the pattern gets a little tighter. Squeeze it a little more, it gets a little tighter. Squeeze it too much, and it ceases to get tighter, and at a certain point may get looser. Before Kimble or Pape or whomever else came up with that concept, no one had any idea it would work that way. And until they constricted the bore too much, they had no idea that there was any such thing as too much constriction. Now, I expect there's a scientific explanation for it. But the discovery was based on art: shooting targets without knowing what the results would be. Pretty much like shooting certain loads to see which ones work better in which gauges and chokes. Balanced load or square load doesn't get us there. Playing around with shells and shooting patterns does. That's art. All the theories and math in the world won't get you there . . . except those theories and math derived from the art that's evolved from 150 years or so of playing around with chokes and loads. What science there is, in those areas, came AFTER a whole lot of trial and error and experimentation. No theory I know of said "3/4 oz is the right load for the 28ga", or "A 1 1/4 oz load will work particularly well in a 12ga". All reached by trial and error. Would've been a whole lot easier if someone with a pencil and paper could have told shooters those things based on whatever theory they might have had . . . but that's not the way it worked.

This is a direct quote from you Larry, which is the post which precipitated this lengthy discussion. For making a poor choice of wording, in my frustration, I humbly appoligize. However I am quite certain both you & myself understood from the get-go this "Relative to Bore Size" was what I was referring to. My posts were all addressed to this point.
Now for the sake of a good honest un-prejudiced discussion indulge me just one more time in a little math, which is actually more in your favor.
Shot deformation is generally accredited to two causes; inertial set back of the charge which affects the rear-most shot the most & barrel scrub occuring to the shot on the outer periphery in contact with the inner barrel wall. Shot cups have eliminated much of the latter & better cushioning have helped a lot with the former.
The inertial set back is of course affected by the length of the column. Hercules/Alliant handloaders guides over the years have given us a convinent chart showing the length of 1oz of shot in the various gauges. This shows the 12ga 1 1/4oz, 16ga 1oz, 20ga 7/8oz & 28ga 3/4oz all having a very similar actual physical length ranging from a short of .84" for the 16ga to a long of .91" for the 28, thus a max variation of less than 10%. Average of the four is .865 which is almost exactly that of the 12ga. Note though this is simply measured length, relative to nothing except the English Inch measuring system. When that "Relative to Bore Dia" is thrown in then what is denoted is the length in ratio to bore diameter or L:D. In this case the 12ga then becomes the shortest @ L:D :: 1.18:1 with the 28 being the longest @ L:D :: 1.65:1. Now for Bob's benefit, you see I am not realy trying to disparage the deceased, just trying to put his work in perspective, I think it quite likely he had a slight lapse in vocabulary (See I'm not the only one) & didn't really intend to put the column length relative to the bore. Most likely he was infering the two shot "Weights" were loaded relative to their bores which resulted in essentially equal column lengths. This I would have agreed with 100%.
To now put the .410 in perspective to this even the 1/2oz load has a 26% longer column length than the average of the 4 gauges above @ 1.09", with 3/4oz of shot it jumps to 1.635" or close to double that .865 average. Relative to bore that 3/4oz load is nearly 4 times as long as it is broad.
Thus when the science is applied the 28ga is not;

a skinny little bore in anything like the sense a .410 is. It is in fact just a slight step below a 20 while it is a giant leap down to the .410. The inertial set back is no greater than the "Larger Gauges", only the bbl contact is increased, but nowhere near that of even the 1/2oz .410 load.
The only Mystery to me is that he apparently did not seem to realize this even prior to his tests. He seems to have "Expected" it to perform more akin to the .410 thus his proclamation it shot better than it was "Supposed" to. Bottom line is the 28 always has & most likely always will shoot much closer to the 20 than to the .410 "Its Scientifically or Ballistically Supposed to" no mystery there at all.
As to the Remington ballistician I note he only applied the 1�oz to the "Pigeon" load, not even all 12ga 1�oz loads. No exact timeline is given for when all those patterns were fired, quite possibly many of them extended back to the pre plastic cushion/shot cup day. It is highly likely that pigeon load as well as most of the 28ga loads (At that point in time primarily intended for target shooters) were loaded with premium shot & the best of other components. These loads could quite well have been expected to pattern better than the run of the mill "Shur-Shot" field loads which were produced in greater quanity to a much closer cost point. Bob doesn't state Neil Oldridge's position with Remington nor what knowledge he should have had on the matter. As he had knowlwdgs of the patterns perhaps he was the man who fired the patterns, but didn't truly investigat what was inside the various loads. Perhaps his surprise re the 28 was that it was so much better than the .410 3/4oz load.
In Bob's own words on the shot-string he him self stated that due to the constraints of the process he was unable to run enough tests to be "Stastically Reliable". This is totally understandable & is not meant as any reflection upon him, but it certainly needs to be borne in mind. I am fully of the belief that if Statistically Reliable data were run with all 4 of the above loads in 12, 16, 20 & 28 all mystery would totally disappear & each would fall into place, producing extremely similar patterns with their effectibeness being proportional to the charge wts.
Until proven otherwise I will stand upon this & can see no magic or mystery involved in hole size. If there were would a.005" over or under bore throw it totally out of kilter??

If you have an older gun that has short cone for the old roll turn over cases,then by all means have the gun rechambered to a modern profile . I have done this on a lot of guns whilst not actually deepening the chamber past it proof tolerances.
About15 years ago long forcing cones became the "in thing" hear in the UK a trend that has now been long forgotten. The proof house did some tests and concluded that there was no or no significant difference in recoil or barrel pressures. The pundits raved on about easier shooting and a reduction in "muzzle flip"{?}.
I was at a game fair on the GTA stand and the subject came up ,I was asked "As professional gunsmith what is your opinion?".
My answer was as follows" I have no opinion ,but at �35.00 a time ,I'll do them all day".

Actually Miller, if you go back and reread, you'll find that "The moving target . . . " quote is one I lifted directly from Brister. His, not mine. That's why I put " " around it.

The difference in column length relative to bore diameter between the 12 and the 28 certainly looks pretty significant to me, even if the length of the two shot columns are quite close. And as I pointed out elsewhere (I think . . . this is getting pretty long!), the difference in bore diameter between the .410 and the 28ga is only about twice what it is between the 28 and the 20. If we go by those measurements . . . then yes, the 28 should indeed perform close to a 20 than to a .410--but not nearly as much closer as it does.

As for the 1 1/4 oz 12ga loads, I did some fairly recent pattern testing on 3 loads, all 1 1/4 oz: 3 1/4 DE, 3 3/4 DE, and I believe the last is max DE (it's a 1500 fps lead load). I'll dig a little and see if I can find my results, but I know how they finished in terms of pattern percentage: In the order I just listed them. The problem these days is finding that old "pigeon load" formula in anything larger than 7 1/2's. In 6's or 5's, it's a great pheasant load.

Found the pattern tests I ran, fall 2008. The 3 loads were Federal Flyer (3 1/4 DE, no longer exists in that format); Winchester Super-X High Brass (3 3/4 DE); and Federal Premium Wing Shok (the 1500 fps load). No cheap "game loads" in the bunch. I did a pellet count on each variety before testing. Test patterns shot at 35 yards (the practical limit of my old backyard testing range). Results: Fed Flyer--91%; Win Super X--86%; Fed 1500 fps--78%. I've achieved similar results in the past when patterning 12ga hunting loads. Too bad all the ammo makers keep pushing more speed on us, because that old pigeon formula has always produced great patterns for me, in several different guns.

Larry;
Maybe, just maybe you're starting to actually think a little, you do however still have a ways to go.
Consider however the 28 & the 20 gauges are much more "Alike" than are the 28ga & the .410. Anyone who "Expects" a major difference in the performance of the 20 & 28 simply have their expectations misplaced.
Discount the occasional shot made where a single pellet happens to luckily strike a vital spot at a range at which the shot should not have actually been fired. Outside this the effective killing range of a shotgun, assuming pellets having adequate penetration, is determined by the density of the pattern insuring adequate hits on the target, but I have no doubt you are fully familiar with this.
Staying with the same size of shot there are three ways of increasing this range, 1; a heavier load of shot, 2; A tighter choke & the third one is a pattern giving a higher rate of central core thickening.
As pointed out even though these various loads have been showed to have very close actual lengths of column (not including the .410) the length relative to bore is significantly different. This puts a higher % of the shot in bore contact. With soft, unprotected shot this is a decided disadvantage due to shot deformation from scrubbing & direct contact with both the forcing & choke cones, many still relate to that.
Many today have made the claim that firing good hard shot with a properly cushioned shot cup the effect given to the smaller bore is that increased central core thickening will give the small gun a longer effective range, even from a choke giving the same overall percentage. The price paid is of course a lesser diameter killing circle requiring more accurate shooting.
There is however no mystery involved here at all, it is pure mathematics.

Gee, 8 pages and all I wanted to know was if forcing cones neede to opened up

After 4 pages I stop reading as either the topic changes or we have another p*ssing contest.......