doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com If a 12ga,16ga, and a 20ga. all loaded with 1oz ?

How is the 410 normally loaded heavier than the 28 gauge? I have a bunch of 1 oz 28 gauge cartridges around. The heaviest I can recall seeing in 410 was 3/4 oz. But in any case same weight for same weight the 28 has the larger bore.

As for the 20 gauge, I believe I said you could buy cartridges for it that were not overloaded. Something not tue of the 410, and if it were true you would have a load like a revolver shot load.

As for column length I'll have to go think a bit. A nominal 16 gauge round ball would weigh 1 oz. If you stack small balls in a cubic array they occupy the same volume as one large ball of the same weight. Settle to smallest volume and it will have the same or lesser volume. A 1 oz shot column should have a length the same or less than the round ball. Is Herc including the wad or soemthing? The math doesn't add up.

If you want the last word on this subject, check Silvio Calabi's authoritative article Less Is More in the latest rendition of Shooting Sportsman magazine:



Kind of embarrassing to realize we've been wasting all these years lugging those 12s, 16s and 20s, when Silvio could have put us straight.

Well now it is quite obvious that 7/8oz is heavier than 3/4oz, but "Read" what I said, "Proportionate to gauge". And "NO" 1 oz of shot will not go into the space occupied by a 1 oz round ball, not even a cylinder having the bore dia & length to fit the round ball. "NO" Hercules/Alliant (I am using both names because this chart appeared in the old Hercules guides prior to becoming Alliant) did not include the wads, only the shot & that in an unprotected bore of nominal gauge size. Also obvious the use of shot collars reduces the dia & thus extends the length. A 1oz shot column in a .662" dia bore (16ga) will occupy about 25% more length than the .662" length occupied by the round ball. But Hey; Don't take my word for it, measure it very carefully, then come back & tell me why I'm wrong.
As to the .410 being loaded heavier, there is a term in ballistics known as "Load Density" (LD) which is Lbs per Sq IN. This refers to the projectile weight in proportion the the area of the bore. The formula for this is LD = W/D² (W = weight in lbs & D = bore dia in inches). Thus a 1/2oz load in a .410" bore has a LD of .186, while a 3/4oz load in a .550" bore (28ga) has a LD of .155. Thus proportionate to the bore dia the 1/2oz load in a .410 is a heavier load than 3/4oz in a 28ga. This is why all .410 loads use a very slow powder, they have a heavier load to lift per SqIn.
The "Proper" definition of a Sq load is still one in which the shot column length = it's dia, because it appears in crossection as a square. A Round ball equivelent is not Square. There is of course no advantage to a load being square to start with. The term is conspicious by it's absence in such notable works as Burrard & other knowledgable ballistics writers.
As to the SS mag if I get a chance to get by the book store may set & read it. Glad I was fore-warned, I certainly wouldn't want to spend any of my limited funds on such "Garbage" as that.

Re the 20 gauge, all I said was that you can go out and buy cartridges off the shelf that are not overloaded. Never said anything about whether they had higher or lower load density than the 28 gauge. My real point was that you can also buy 20 gauge cartridges off the shelf that are overloaded, and if the gun is matched to these over loads you have a 20 gauge with the weight of a 16 or 12 gauge and a bore too small for the load.

I will agree that a “square load” is defined as one with the column length equal to the diameter, and also, that it’s a rather meaningless concept. It’s a rule that can actually apply to only one gauge, whatever gauge you want to make it.

And yes the 410 with ½ oz has a higher load density than a 28 with ¾ oz. In line with my point that for any practical hunting purpose the 28 is superior to the 410 in every way since both guns will probably be in the same weight class and anything less than ¾ oz is really a handicap on pheasant. Even well centered on the target, ¾ oz implies you should pass up anything beyond 40 yards.

Consider a subdivided cube like a Rubik’s cube. If you have one ball filling the entire cube, or 27 balls, each filling one sub-cube, you have exactly the same weight. If you want to make a number of small balls fill a cube to exceed the weight of a single ball, then you have a packing problem. But the only way to make them occupy a greater volume is to have space between them. This situation changes slightly with a cylinder where you will have boundary effects since it’s not a cube, but that would be a relatively minor effect if the balls are small compared to the cylinder as is the case with a load of birdshot. So I am still puzzled as to how you are going to make a 1 oz column longer than a 1 oz ball short of using a filler. I confess to not having looked at any load data of late, the above is based on simple geometry. Just for laughs, I will toss this problem up on a math related board I am a member of and see what they make of it. It’ll make a good sanity check.

Well unspellable, you actually answered your own question, if you just give it a little thought. The fact is when you load those little round shot "Each & Every" one of them have air space around them. They don't fit in tight like those cubes in the Rubik cube. Present day Hornady (Formerly Bair/Pacific) charge bushings are listed by their dia, all being 1.0" long. Fomerly the dia of their shot bushings were also listed. A 1¼oz bushing was listed as .664". (16ga = .662"). Note however this bushing is 1.0" long. The sq load in a 16ga would be only .662" long. .662 x 1¼ = .828oz.
This calculates out to .277 SqIn per oz while Alliant's figures work to .288 SqIn per oz. A slight variation probably attritbutable to a different size shot or different alloy or both being used. A .662" dia cylinder x .662" long however has a volume of .228 SqIn. It will therefore hold nowhere near an oz of shot., closer to 13/16oz. The loads I am aware of that come closest to being "Square" are the old 1¼oz 10ga load & the British gamegun load of 1 1/16oz. Funny thing is I have never seen either of these loads bragged upon because they are Square. Usual references is to the 1oz 16ga & 3/4oz 28ga loads. Neither are actually square, one is a Round ball equiv & the other is neither. A 28ga Rd Ball equiv is a little over 9/16oz & the Sq load just over 7/16oz.
I cannot recall ever seeing anything by an ammunition Co or "Real ballistician" even mentioning a square load. It is uaually some one trying to "Build Up" their personal pick of gauge. The hillarious part is all the "Proof" they go through, if it actuall meant anything at all would have just "Proved" their choice totally worhtless. Fortunately for those who like different gauges (I like them all from 28ga up) They are totally "Non-Dependant" upon a sq load.
Each step up in gauge though gives a little more versatility in the loads it will handle & allows for heavier loads to be used. All of us though may not need the maximum possible loads & each person just needs to decide what suits their purpose.
But again there is "NO Magic" bore size Nor is there any advantage to a SQ load. Personally I see no reason at all in "Magnumizing" the small bores. 3/4oz in 28ga, 1oz in 20ga & 1 1/8oz in 16ga are all fairly heavy in proportion to their bore dias, & as far as I am concerened their working limit. Even these are more appropriate to modern guns capable of handling SAAMI pressures. For anything more I prefer to step up in size, rather than using continuously longer shot columns in a smaller hole.

The Rubik's cube example is for the volume of the spheres packed in it, not the volume of the cubes. I have handed this over to my collection of math geniuses. Jury is still out, it's slow going as over there the moderator has to approve the posting before it goes up. First guy to tackle it assumed we were adding the shot to the ball, so I had to get it back on track.

Variation in the shot lead alloy should produce an error of no more than 1%. Irregularity of shot and edge effects would produce a larger error.

Meanwhile, I am very much with you on the question of gauge and loading. I have always maintained that if you want to launch a 12 gauge load, launch it from a 12 gauge. It seems to be an American habit that we are always trying to make the next smaller gauge do the bigger gauge's job. Magnumitis I guess.

Speaking of 9/16 oz, I have some 2-1/2 inch 28 gauge with 9/16 oz shot. (Fiocchi as I recall.) The box says 8 in the glossy print but says 4 in the little white square. So what size shot is it? (Before I am reduced to opening one. I have these for my 1911 Ithica Flues.)

I think you are going to have to open one of those shells & see what the shot is. It can't be MM as a 4MM (.1575") would equal to about a #1 US shot size, #8 being about 2.25mm. Burrard had a comparsion chart for various countries & gave Italian #8 as 450/oz while US #8 is usually given as about 410/oz. Certainly not enough difference to account for #8 & #4.

Amen.

During the first few years that I shot competitive sporting clays, I tried 8 different guns in 4 gauges, and ended up shooting my best scores with a 20 gauge Beretta O/U. I did better with that 20 than with any of the three 12 gauge guns I used. I never did a comparison of test patterns, but the results on clays were clear.

In the 20 I used 1 oz Winchester AA target ammo, and once in a while 1 1/8 oz Winchester Double-X field loads (2 3/4") with buffered, copper-plated shot, with excellent results. The only reason I didn't shoot more of the 1 1/8 oz loads was they cost over $12 a box!

I enjoyed a lot of success with that 20 gauge gun before I finally found a 12 gauge with the right combination of weight, balance, and stock fit to equal the 20.

The replies to this thread have used a lot of facts, myths, and speculation in an attempt to prove that 1 oz or 1 1/8 oz loads don't work as well in a 20 gauge as in a 12 gauge. My experience clearly demonstrated to me that, while all the theories may be true, the effect is so small that it is easily overshadowed by other factors.

The bottom line is, forget the theories and the pronouncements of "experts", and shoot whatever works for you.

SHOT SIZES

US UK Italian
mm inches mm inches mm inches
4 3.3 .13 2.8 .11 3.1 .122
5 3.0 .12 2.67 .105 2.9 .1142
6 2.8 .11 2.54 .10 2.7 .1063
7 2.54 .10 2.4 .095 2.5 .0984
8 2.3 .09 2.29 .09 2.3 .0906


1 mm = .0394 “

1 inch = 25.4 mm

UK sizes:
http://www.kwacs.org.uk/barrels&choke.htm
http://www.hrwscothunt.ndtilda.co.uk/info/data.htm

Eley Shooter's Diary, 2005, gives different numbers:
Brit 4's 3.1mm, .12", 170/oz
5's 2.8mm, .11", 220/oz
6's 2.6mm, .10", 270/oz

Italian sizes:
http://www.bandpusa.com/files/productguide-USA-2005.pdf