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SMALL BORES AND SHOT SELECTION

By Marshall Williams.

 

      I first became aware of the .410 bore shotgun at about age 10 while vacationing at a cousin's farm.  A neighbor boy had a Savage .22/.410 over-and-under, the first that I had ever seen, and both the combination gun design and the strange and skinny new shot shell made lasting impressions on me.  Upon seeing that gun, I decided it had to be the most useful gun, if not in the whole world, certainly in the halcyon world of a country boy in the late 40s or early 50s.  I note that an additional 50 years of increasingly sophisticated shotgun experience have failed to alter that opinion.

     Under close supervision, I was allowed to shoot the .22 barrel, but not the impressive shotgun barrel.  My older brother shot it, however, and the mess it made of a tomato can sitting on a fence post about fifteen yards away left a strong impression on me.  I had once fired a 12 gauge shotgun at a much longer range.  My shot had resulted in a few pellet holes in a paper target, but the tomato can was demolished.  That set an image of awesome power in my childish mind, and I looked forward to the day when I would have such an effective weapon for my own. 

     A few years later, my father bought me a .410, but it was a three-shot, bolt action Mossberg.  I had been campaigning for either a Savage over-under, such as I had seen, or a used 12 gauge double that caught my eye at a local hardware store.  My father looked at the double and saw too many burred screw heads, one of which clearly was a brass replacement.  That ruled out the double.  We had a good .22 rifle, rendering the .22 option unimportant.  Finally, at $24.95, the Mossberg seemed a better buy than the Savage which at the time retailed for $39.95.  A box of three inch .410 shells loaded with #6s, added another $2.15 to the tab.  (There was no sales tax.  As John Lennon said, "Imagine.")

     My father was not a particularly enthusiastic shooter or hunter, but he had grown up on a farm where guns were every day tools and hunting was part of feeding the family.  The experience had given him more gun savvy than one might imagine.  Certainly more than I had gleaned from reading a few issues of Sports Afield and Outdoor life.  He thought #8s or #7s would be better all around than #6s.  Those were sizes he had used for general farm purposes at some earlier time in his life, but #6s were the smallest size available at the store.  (In fact, at that time the factories had dropped #7s altogether and did not load #8s in .410 shells.)

     Armed with the gun and shells and a couple of shirt cardboards for targets, we rode out in the country and patterned my new gun.  The little gun came with two detachable choke tubes, one marked modified and the other full, and a little wrench to change them.  We tried a shot with each and found two different types of patterns, the full choke quite tight and the modified a little more open.  I decided that the full choke would kill farther and deader than the modified choke.  That conclusion is correct, but I also concluded that the full choke tube was the one to use for hunting.  This proposition is a little harder to support.

     At the time I got my first shotgun, nearly every shotgun I had ever seen had a full choke.  In my part of the world, there was no duck hunting, and I remember only one person who shot doves.  Except for quail hunting, shotguns were used more like rifles, to shoot targets sitting still on the ground or in trees, targets like sitting rabbits, treed squirrels, possums, and raccoons, the rare deer, bear, or turkey, but hardly ever for flying birds.  In shooting at targets that are standing still, a full choke is no handicap and even can be an advantage.  It is like a short range rifle with a built in margin for error in aiming.

     In fact, the only moving target practice I remember was shooting at hand-thrown tin cans.  Since I could hit these with a .22 rifle, I did not find the full choke to be a handicap.  A few years later I took up Skeet, and the discovery of open chokes was a revelation.

     Another revelation came when I learned how large shot thins out patterns.  My father had bought me a box of #6s because that was the smallest shot the hardware store carried for .410s.  I presume that the store owner stocked what his customers wanted.  In those days, the full choke .410 was especially favored for squirrel shooting.  My early success with #6s kept me using them until I loaned a few shells to a friend.  He paid me back with shells loaded with #5s.  As I also succeeded in shooting a few rabbits with these, I was led to the common sense conclusion that a large pellet had more power at long range.  Therefore, large shot was better for long ranges.  Like the full choke idea, I would soon discover this one was wrong as well.

     As the nearby table shows, an ounce of #6s contains about 220 pellets.  My old three inch shells contained 3/4 ounce rather than the current 11/16 ounce.  Thus I had about 165 pellets in the shell.  A thirty inch circle contains 707 square inches and 70% of 165 is only about 116 pellets.  That makes for a sparse pattern even with a full choke.  As my father had observed, #7s or #8s would be better.

     The shot sizing system is very mysterious and very misleading.  One might think that #4s are twice as big as #2s.  They are in the metric system.  But, nope, #2s are bigger than #4s.  Well, then, are #2s twice as big as #4s?  Nope, #2s are twice as big as #5s (and that is only a coincidence).  Considering that shotgun gauges represent the number of bore-sized pure lead balls that can be made from one pound of lead.  Are shot sizes related to that system?  Nope.  Then what do the numbers mean?

     Like most things related to shotguns, the shot sizing system is traditional, but does not relate to any modern concepts of how we measure things.  It is based on subtracting the shot size times 1/100 of an inch from a base number, 17/100 of an inch.  Thus, to find the diameter of a #4 shot, we subtract 4/100ths from 17/100ths and find that a #4 is 13/100ths of an inch in diameter.  In decimals, it looks like this: .17" - .04" = .13".  For a #7 1/2, it would be: .17 - .075 = .095".  I have no idea how this system came about.  A .17" diameter pellet is a "B" (a "BB" is .18" in diameter).  Nearby, I append a table of common fine shot sizes and the approximate number in an ounce.

     Such a system is very misleading.  Since the diameter of the shot is a linear measure, and the volume of the shot is a cubic measure, the number of pellets in an ounce of shot changes dramatically as the numbers get slightly larger.  The difference between and ounce of #4s at 135 and an ounce of #5s at 170 is not so great.  The difference between an ounce of #8s at 410 and an ounce of #9s at 585 is rather more dramatic.

     At some other time, I have opined that an ounce of #7 1/2s from a full choke gun is effective in taking doves to 40 yards.  If you wanted equal effectiveness at 30 yards, you could use a lighter charge of smaller shot in a more open degree of choke.  It is possible to make some very good guesses about how much less shot would be required and what size to use.

     Because much of what I do best involves playing with numbers and simple math concepts, some people may think I am making mathematically precise statements. I am not!  There ain't nuthin' precise about shotgun patterns!  However, our best guesses must bear some relationship to reality and the math is the reality to which our guesses relate.

     Thus, when I say an ounce of #7 1/2s from a full choke will take doves at 40 yards, that's an average statement.  In practice, sometimes it will take doves at noticeably longer ranges and other times will fail to take them at noticeably shorter ranges.  However it is a pretty good general proposition.  Even saying an ounce of #7 1/2s has 345 pellets, is an approximation.

     What do we know about a full choke pattern made by one ounce of #7 1/2s at 40 yards?  We know an ounce of 7 1/2s has about 345 pellets; a full choke pattern places about 70% of those pellets, about 242 of them, in a 30 inch circle at 40 yards; and each individual pellet has an energy of about 1 ft. lb.

     Let us consider that we want to use a small bore gun with 3/4 ounce of shot that would give us a 70% pattern in a 30 circle at a modest 30 yards.  Can we do that?  Yes.  People do it all the time with the 28 gauge and .410.

     First we have to consider what choke will give us a 70% pattern in a 30 inch circle at the shorter range, 30 yards.  That would be about an Improved Cylinder.  Then, what size shot would give 345 pellets in 3/4 ounce?  Well it would be between an 8 with about 307 in 3/4 ounce and an 8 1/2 with about 365.  The energy level of the 8s would be better, while pattern density with 8 1/2s would be better.  I would choose the 8 1/2s because I prefer pattern density to pellet energy, but the 8s would be close enough.  The lethality of the smaller pellet at the shorter range is quite comparable to the lethality of the larger pellet at the longer range.

     I have often mentioned that the .410 is a short range shotgun; so is the 28 gauge.  Both should be used for targets within their ranges and, therefore, both should have open chokes.  However, because of the shorter ranges at which they are used, both also should use smaller shot than one uses for similar targets at longer ranges. 

     When I shoot small bores, and I shoot both the .410s and 28s a lot, I adjust my shot selection to suit the shorter ranges at which I use the guns.  As a general rule of thumb, I use shot that is a size smaller than usual recommendations.

TABLE OF SHOT SIZES

     Fine shot sizes are found by subtracting the shot size from .17 inch.  Thus a number fine 2 shot is .15 inch in diameter, a number 7 1/2 shot is .095 inches in diameter.  Common shot sizes are:

 

Size Diameter No in 1 Oz.
  inches  
2 .15 88
4 .13 135
5 .12 170
6 .11 220
7 1/2 .095 345
8 .09 410
9 .08 585

     If one counted a lot of shot, he might discover a substantial variation in the number of pellets of a nominal size in an ounce.  That is because the pellets are not precisely the size shown.  Due to "screening" practices, they may be any size from a half size larger to a half size smaller than the nominal diameter.  As a general rule of thumb, the number of pellets in an ounce should be considered to be +  or - 10%.


 

Reprinted curtesy of Shotgun Sports Magazine, P.O. Box 6810, Auburn, CA 95604. www.shotgunsportsmagazine.com