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American Shot Sizes part I: Birdshot – Shotguns 101 #1


Shot sizes are one of most confusing aspects
of the shotgun world. For newcomers, all those arbitrary letters and numbers are an utter
mystery; and even many experienced shooters can’t keep track of all the different sizes,
their diameters, and how they’re organized. And every shot size chart or table I’ve
come across is incomplete in one way or another. So I figured I’d kick off this new video
series with an exhaustive, two-part video guide that covers all of the American shot
sizes, common and uncommon. I’ll explain the various formulas and naming conventions,
and touch briefly on what the different sizes are used for.
I’ll explain some basics and try to keep things easy for newcomers to follow, but even
experienced shooters should be able to learn something new here.
Now, the American shot size system isn’t the only one in the world, but trying to include
others in the same video would just be confusing – especially with birdshot, where the same
numbers and letters refer to different diameters in different systems.
A majority of my viewers live in areas that predominately use American shot sizes, so
that’s what I’ll cover first. Other shot size systems will get their own videos later
on. I’ll get to specific sizes shortly, but
first, some definitions and background: For the purposes of this video, shot refers
to spherical projectiles fired two or more at a time from a firearm. Shot size is either
the nominal diameter of the pellets, or the standardized name representing that diameter.
Non-spherical shot exists, but I’ve never come across a standard size system for those
projectiles, and they only show up in a handful of novelty or specialty shotshells anyway.
Shot can be made from a variety of materials, but I won’t get into that much in this video
because standard shot sizes are the same for all materials. Despite some misleading charts,
there aren’t separate size systems for lead and steel shot.
As used in firearms, shot can be separated into two major varieties: smaller birdshot,
and larger buckshot. Both are round pellets fired manifoldly, but they can be distinguished
by their size, the way they’re loaded, their ballistic properties, and how they’re used.
The next video will cover buckshot; this video will focus on birdshot.
Birdshot is very much the characteristic shotgun payload. Dozens, hundreds, even thousands
of birdshot pellets are fired simultaneously, and spread out in flight to create a wide
cloud – called a pattern – that improves the shooter’s chances of hitting small, fast-moving,
and/or distant targets. The idea is that with the right pattern; a
target anywhere inside will be hit by enough pellets to get the job done.
This is the kind of behavior most folks associate with shotguns – sometimes incorrectly so,
but more on that in the next video. As the name suggests, birdshot is used on
all types of birds, along with other small game animals, pests, and varmints; and inanimate
objects like the breakable clay discs used in various shooting activities.
Because birdshot pellets are relatively small and used in large numbers, the amount of birdshot
in a shell is typically described by the total weight or mass of shot, usually in ounces
or grams. When it’s loaded, the shot is measured out by weight or an equivalent volume,
not by a specific number of pellets. Ammo manufacturers may give pellet counts
in addition to the weight of shot, but these numbers are almost always estimates.
Standard American birdshot ranges from the size of a grain of sand to just below the
smallest buckshot in steps of one hundredth of an inch. There are also accepted half-sizes
that cut that step to just five thousandths of an inch.
That’s less than the thickness of one of my beard hairs.
All these birdshot sizes are split between two major naming systems. The smaller sizes
use a system of numbers, while larger sizes are designated by letters. We’ll run through
the sizes, starting at the bottom with the numbered birdshot.
The way these numbers work, the lower the number, the larger the pellet. It’s a little
counterintuitive, but there’s a handy mathematical formula that relates these numbers to their
corresponding pellet diameter. Simply take the shot size number, subtract
it from seventeen, and the difference is the nominal pellet diameter in hundredths of an
inch. Take #5 birdshot as an example. 17 minus 5
is 12. Move the decimal point two places to the left, and #5 birdshot pellets are .12
inches in diameter. This formula also holds true for non-integer
numbers, allowing for half sizes such as 7½. 17 minus 7.5 is 9.5, or .095 inches. The numbered birdshot sizes start at #12, which is .05 inches in diameter, followed
by #11, and #10. Anything smaller than #12 is simply called “dust shot”, though sometimes
#11 and #12 are also referred to as dust shot. Because of their very low mass, tiny #10,
11, and 12 pellets are only effective on small animals at very close ranges. For that reason,
these sizes are used primarily for pest control, and are often called rat-shot or snake-shot.
You won’t see many actual shotgun shells factory-loaded with this tiny shot nowadays;
but it does show up in specialty shotshells and pistol cartridges, and the shot by itself
can be obtained for handloading. Moving up the scale, we have #9, 8, and 7
shot. Unlike minuscule #10 and smaller sizes, this
shot is heavy enough to remain effective beyond absolute point-blank ranges, but still provides
very high pellet counts and large, dense patterns that are ideal for fragile, but small or fast-moving
targets such as clays or small game animals. Also in this range are #7 ½ and #8 ½ birdshot.
These are the only common half-sizes in the American system, though others can be defined.
When dealing with pellets this small, half-sizes offer relatively significant changes in pellet
count, and with the way these sizes are made and used, it makes sense to have these intermediaries.
Since #9 through #7 lead birdshot is less expensive to manufacture than most larger
sizes, they’re what you’ll usually find in cheap, steel-based, bulk-pack shotshells
that are great for inexpensive plinking and training.
Next, #6, #5, and #4 birdshot are popular for hunting most upland game, as well as smaller
or close-range waterfowl. .125” #4 ½ shot isn’t unheard of. Some
reloading suppliers offer slightly oversized #4 shot that’s technically #4 ½. And since
that’s exactly one-eighth of an inch, metal balls from various other sources can be repurposed
as shot. But if you see shotgun ammunition specifically
marked as #4 ½ birdshot – or 5 ½, or 6 ½ – you’re more likely dealing with a different
shot size system. British birdshot sizes include #4 ½, but that’s similar to American #6.
Above #4 is #3, #2, and #1 birdshot. These bigger pellets are used primarily on waterfowl;
offering the penetration and energy retention needed for big, tough birds like geese, or
long-range shots at high-flying game. At .16 inches in diameter, #1 shot tops off
the numbered birdshot sizes. Larger sizes still move up in hundredth-inch increments,
but the math is replaced by a new system of letters and tuples.
The sizes just above #1 are the “B”s. At .17 inches – what would have been #0
by the number-size formula – is B shot. After that, we have BB shot at .18 inches, and triple-B
at .19 inches. If that middle one rings a bell, yes, .18-caliber
BB birdshot was the original basis for the name and bore size of BB air guns. However,
air rifles have evolved some since their introduction, and the standard pellet size for modern BB
guns is 4.5 mm, or .177-caliber. Also, it’s worth mentioning that “BB”
is often used as a catch-all term for shotgun pellets. If someone uses “BB” as a plural
noun, as in “I like magnum shells because they hold more BBs”, they probably just
mean pellets in general, not necessarily BB-size pellets.
Anyway, above triple-B, there’s no quadruple-B. Instead, things start over with a new letter,
and we have .20-caliber T shot and .21-caliber TT shot. Then, the letter changes once more
to give us .22-caliber F shot – sometimes called triple-T – and .23-caliber FF shot.
The “B’s” and “T’s” are common steel shot sizes for waterfowl hunting in
areas where lead has been banned. Since steel shot has a relatively low density, achieving
the same penetration and effective range requires larger pellets.
The biggest “T” and “F” birdshot sizes are also used on thin-skinned varmints and
predators like coyotes and wild cats. Compared to buckshot, these sizes offer higher pellet
counts at the expense of some range and penetration. There’s no handy formula for these letter
birdshot sizes, but they’re not too tough to keep track of. Just remember that “B”
shot is essentially #0 at .17-caliber, then the other two “B”s, the “T”s, and
the “F”s follow in the usual hundredth-inch increments.
The “F” sizes top off the American birdshot system. One hundredth of an inch above FF
is the smallest buckshot size, .24-caliber #4 buck. We’ll start there next time.
All in all, American birdshot isn’t too difficult to grasp and remember once you see
how the system works. Stay tuned for part 2 on buckshot, where things get somewhat less
straightforward. For now, I welcome any questions and comments,
and please let me know if there are any general shotgun topics you’d like me to explain.
I’ve been planning this new video series for a while, and now that it’s finally off
the ground, I’m looking forward to feedback. Until next time, have fun and shoot safe.

100 thoughts on “American Shot Sizes part I: Birdshot – Shotguns 101 #1

  1. Thank you very much Sync, excellently done video. Very informative for me since I'm just about to get into shotgun.
    A question: I'm not interested in skeet, just basic hunting and a "survival" situation, e.g. – hunting various birds for food. I live in Canada and I have found that getting shotgun reloading supplies is difficult up here. So by your video and the fact that shotgun pellets supply are rare, I'm thinking of using bb's for reloading. I have been recommended the 12 gauge Remington 3" 870 express. (16 gauge was discouraged by local gun shop) What are your comments, if any, on this rifle and just using bb's for reloading. Thank you.

  2. I love your videos! Every time I watch one, I literally leave with several things I just never knew or even thought about.

  3. I just bought some 12g, 3", 1-1/4 BB. how big would those pellets be? I'm just using it for targets and dot want a huge spread.

  4. Thank you for this informative series regarding guage history and an understanding of why shotgun guage is what it is.

    This truly helps me understand the nuances of why the obscure guages were developed and why they are now hard to locate.

    Much appreciated,

    Rick Mansberger

  5. I just want to comment on how greatly the graphics helped in this video. I watched the second video about buckshot, and the video is even better in that one since it is animated graphics. I came back to this one to refresh my knowledge on bird shot, because it is on sale now at walmart, and I just bought a shotgun, and wanted some ammo to shoot at the range to get the feel of the gun.
    Now I know how to understand the info on the shell boxes.
    Thanks!
    I, as someone who has no idea how to even begin to do graphics, and animation, just want to compliment Synchro on an excellent explanatory video. And I really mean that. A lot of other vids draw pictures on paper or white board; thanks for taking the time to do the computer graphics.

  6. Excellent video, Mr. Synchronizer!
    Very clear and erudite presentation. Thank you, this is just what I need as I expect arrival of my first shotgun and anticipate my first training class shortly.I have a couple of questions, if you have time:
    1. You mention in another comment that "spread" is a function of the choke—that makes complete sense in in my head, from a logical standpoint, however you also mention in this video that birdshot shells are manufactured to have a wider spread than buckshot. How does the shell contraction affect the spread?2. On the same subject, you mention in your #2 (buckshot) video that manufacturers sometimes market things like "#5 Buckshot" which is really just birdshot—is it "exactly" the same as the birdshot of the same number or (relating to my first question) are they trying to produce a shell that uses birdshot size and weight but produces a buckshot-like spread?Sorry to be so overly-detailed but since my first class is focused on home defense, and I'll be using a 20 gauge 18.5" smooth cylindrical barrel, I'm interested in finding close (ish) patterned ammo still light enough to spend all day punching cardboard without too much abuse to my aging shoulders :)Thanks again—I've only watched #1 & #2 so far. I'm about to spool up #3 now… 🙂

  7. Man thank you so much for this series. I know guns, but clueless about shotguns, and the different shots. I just bought a Maverick 88, and now I'm looking to learn what I can about the different shells. What a wealth of info. I'm saving your videos and passing them to a friend to learn as well. I can't thank you enough.

  8. Kuddos to you for your excellent presentation which is 110% professional. I am new to shotgun world both shooting and reloading and this information is just what the "doctor" ordered to get me up to speed, and I am looking forward to ALL your other videos. I found your list of programs used to produce this video astounding and really gives an insight to the complexities of producing such an educational video.  Also I really appreciate your opening NOT featuring blaring ear-grinding music with gun shot pops.

  9. Like the shirt and your sense of humor. Very helpful video, as I am totally new to Shotguns. You packed a lot of info into less than 10 minutes. Thanks for taking the time to make these videos. Subscribed.

  10. I've been shooting for more than 35 years and still managed to learn something. Well laid out and relevant video. good job.

  11. Excellent! As mentioned at the outset, valuable for beginners & experienced shooters alike. You have a very clear narrative voice, and perfect media selection; charts, photos, and brief videos, to pair with your descriptions, that made your definitions easy to commit to memory.

  12. outstanding video, thank you! what do you think about using 20 gauge 2 3/4 #5 shot, or 3 inch magnum #2 shot for home defense? thanks

  13. Excellent, extremely informative video. Thank you. So, you do not suggest birdshot for home defense? Even T or F?

  14. Thank you so much for this series! I am experienced with regular firearms, but relatively new to shotguns. I am surprised they do not measure the length of a shotgun barrel in cubits! Thanks to you and your mathematical mind it starts to make a little more sense.

  15. Very informative, thank you. I'm going goose hunting for the first time this year and I picked up two loads; 3 1/2' BB and 3' #4. My targets will be close; 15 to 30 yards. Any of these loads over kill? Thanks and anyone can answer.

  16. I recently purchased a mossberg model 510 caliber 410 shotgun. It is choked for either 2 1/2 to 3 inch shells. Right now I am using a 2 1/2 inch shell with a #9 shot that I am not happy with. Question I have is can I open these shells and substitute the #9 shot using copperhead daisy BB's and if I can how many per load !?!?! I have thousands of these copperhead BB's and would like to use as a reload replacement for these #9's if I can !?!?!? Thanks Scott

  17. GREAT Video !!!
    Callahan Auto Parts came from a great movie, Tommy Boy. I grew up in Sandusky Ohio and can tell you first hand that they never existed. Love the shirt 🙂

  18. I love the VHS tv in the background. I feel like traveling back in time to use youtube for educational purposes and cooking a turkey in microwave right now.

  19. Finally someone explained that BB term!!!
    In Russia we have 0 (zero) for B, 00, 000 and 0000… and even uncommon 00000 and 000000 but those are technically a buckshot.

  20. Hi! I just discovered your video series. Kudos to you, wonderful job w/o self indulgence. I will be watching many of them.

  21. Notice the Odd jump from .32 caliber #0 Buck and .33 Caliber #00 and how starting and #1 Buck it's .30 caliber and goes up in size by 2 caliber?????? Ever wonder why??? Here be why……………..#00 is not actually .330 it's real design was .340 caliber exactly two calibers larger then #0 Buckshot. When Winchester introduced the Mark-5 shot wrap plastic collar they had to cut pellet size diameter of #00 buckshot from .340 to .330 and most of the pellets ended up being .328 exactly in size. This marketing trick did tighten up patterns a tad bit in most all guns but not all. Federal and Remington followed by using shot cups like the SP-12 but Remington's #00 was exactly .330 with a few .328 mixed pellet in there but the SP-12 wad petals are so thin they allow for the 1 thousandth smaller .330 caliber balls to fit snug with dimples on the case walls. 12 pellet Remington Magnum #00 did use the full bore .340 pellets but they probably stopped and just loaded it now with the .330 caliber pellets.
    All other companies like Hornady use .320 .325 #0 or #0 1/2 inside their Buckshot and call it #00 for marketing purposes. Federal uses a .330 and .328 caliber pellet and has no #0 Buckshot offering because of this…………..They felt that marketing both would be a outright lie and so did Winchester so both companies dropped their #0 Buckshot loads of 12 pellets and continued to market the #00 undersized .330 .328 .325 caliber pellets as true #00 when in all actual sales………………..It's no place close to a .34 caliber lug of a pellet that the old postal 10 gauge loads used to throw. #00 is only a sales marketing gimmick to get people to buy s special kil-em up and all tacticool special do it all 100 yard buckshot………………..when any good shotgunman knows that pattern density and pattern consistency mean more then tight patterns here and there. Flight control is actually very inconsistent if you shoot 25 shots of it at 25 yards range you will see that it has a very varied consistency in it's pattern tightness and pattern performance. One shot might pattern dickens tight as hell at 25 yards and shot #10 or #5 might pattern way looser then the original shots. Believe me I have done the testing……………the company just relies on us to only pattern 2-3 shots and call it a day game over. This also varies gun to gun………all shotguns act different due to different barrel bore sizes, forcing cone lengths, chokes, polish of barrel, friction of steel type, wind, rain, air, temp. Way to many variables to always be the same gun to gun.

  22. Ideal 12 gauge Buckshot load for 0-40 yard use is actually the only size not offered or sold in America………….#2 Buckshot .270 caliber dead true. It allows for 5 pellets per layer and 5 layers for 25 pellets in the load all .270 caliber but that's a magnum load. 5×4 = 20 pellets for a normal HV field load of #2 Buckshot which also just happens to be the magic Magnum. When Winchester was still loading it's Supreme 20 pellet #1 Buckshot XX Magnum it used a shot cup and it substituted #2 1/2 Buckshot .285 caliber pellets or .280 caliber pellets closer to #2 Buck then #1 Buck. This load was close to 1 5/8 or 1 7/8 oz in a 2 3/4" inch shell and was considered the best patterning hardest kicking filling jarring shotgun load one could shove into a 12 gauge tube………………….( Madness ) some called it. Problem was it was just to god damn good to sell so they took it off the market in 2004.
    Ever ask questions??? Why is no 12 gauge #2 Buckshot sold in America now or why no #0 Buck loads other then Remington??? Ask and yee shall receive thine answer

  23. Notice the Tungsten chart also…………………..This is why i refuse to pay for Heavy Shot Environ-metal shells now. At first they used a load similar to Tungsten Iron nickle and you got what you paid for per shell……………………about 50% Tungsten. Then they started to scam and cheat the customer % based when they kept charging high $$$$ for a lower % Tungsten cheaper shot product that was closer to the Charts Tungsten, Iron, Copper, Nickle alloy. It was not as good nor anything close to the original Dead Coyote T shot or Goose loads.
    The only other product that was worth a shit was the Kent Tungsten Matrix Poly Nylon #11 95% Tungsten over 15 grams per cubic CC. Kent Bismuth was also great at 9.8 grams per cubic cc. Winchester loaded a good mix 15 grams per cubic cc heavy load but it's gone now thanks to China prices of Tungsten going up.
    Never pay for the Tungsten Super Shot 18 gram per cubic CC even though it is great shit and claimed to be true to the % you still never know what your paying so much $$$$$$ for when you load or shoot it. For all we know it's only = Lead 12.5 12.0 grams per cubic cc roughly depending on alloy antimony %. it seems complex and it is in some ways but shot is not shot simple stuff. If your used to a load on a game animal like Geese or Turkey or Ducks and you normally shot Lead #4 around the board for all 3 animals and then were forced to change shells and shot type it got real confusing and hard to make kills cleanly.

  24. Also of note…………………………Why some shooters want to use a 12 10 or 16 gauge shotgun and then use the tiny small pellet sizes like #4 Lead or #6 Lead to shoot Coyote and Foxes is stupid not humane and beyond my understanding. Turkey hunters will claim that they see Coyote a lot and this is true but they also try to claim that they only have #6 or #5 #4 Lead shot on them or smaller #8 Heavy Shot Tungsten stuff. If you hunt Turkey and you think you might see Coyote then you need to carry a shot size large enough to be humane . Some may have time to reload a shell but most wont…………………….I say to a lot of them when it comes up in discussions to simply Turkey hunt with Lead #2 #BB and no less like the old timers did. They did not fool with this Head shooting Turkey crap unless the bird was 25 yards or less range………….further out they simply shot the bird in the body using large shot for a large ass bird like Goose Hunters still do to this damn day!!!!!!!!!! When Lead was legal Goose hunters used #4 Lead over decoy if ducks were expected and #2 #BB for pass shooting Geese and even #4 Buckshot for super high Geese………( Lead FF F TT T BBB ) shot did not exist except for reload and it was rare. In the days of old as we call them now days……….the Goose hunter and Turkey hunter were often the same man or men. To kill a Turkey one would train dogs or catch the birds on the roost…….or call them in when spring time hunting. Once you located a roost if calling did not work one would sneak into the roost area and simply blast the Gobbler off the roost with #BB #2 Lead shot to the upper neck and body area. If calling them in one would also simply blast them with Lead #BB or #2 at even 40-50 yards range just like shooting Geese. This would not have worked for sales of remaining Lead Magnum Goose and Duck loads in #4 #5 #6 shot so the government and the forest services came up with the head neck shoot idea and Turkey calling style of hunting and sales to people…………………………..( No one had even seen a fucking Turkey in 1980 ) in most states little alone hunt one or kill one. The forced Steel Shot for Goose and Duck caused Winchester and Federal to be over stocked with Magnum 12 16 20 and 10 gauge Lead 3" inch and 2 3/4" inch shells……………..millions of them!!!! how o how to get rid of all those 3' inch Magnum #6 #5 #4 shot shells…mmmmmmmmmmmmmmmmmm I know boss we can pack them into more expensive 10 shot packs and call them special Turkey boom boom shells and put a Turkey on the Box……..that'll sell the fuck tard out of them

  25. You would be oddly ashamed to know how many hunters have no clue how big or what shot sizes are appropriate for what game animals…………………….hence the reason Turkey hunters in America got into the trend of head and neck shooting Turkey with #6 #5 #4 and even #7.5 size shot……………………………………………………..It all started when they made steel shot mandatory for waterfowl birds and the industry had thousands of Lead 3" inch Magnum #4 #5 #6 shells on the market in storage still. To sell them all off in the 90's they came up with Turkey hunting as the new big trend in hunting shit……….thus they marketed head shooting Turkey with magnums in #4 #5 #6 shot as they key to hunting Gobblers and they even packed 3" inch magnum shells into neat 10 round packs to sell cheaper then 25 round packs but they priced the 10 packs more expensive in the long run of things. That way they got rid of all the shells rather then being stuck with them. They still got stuck with odd load like #BB Lead and #2 Lead in shells like 16 gauge 2 3/4" inch magnum 1 1/4 oz loads or the baby magnums as they called them…………………….interestingly enough these sizes of shot dropped off the map for years and Remington was the last company I know to load a 12 gauge 2 3/4" inch Lead #2 Shot into 1 1/4 oz shells. Federal still had a Premium #BB 3" inch magnum shell but it never gets run and is only limited run available every few years now. They also managed to get rid of lots of that Lead #BB #2 shot by loading it into .410 self defense handgun ammo and special HD/SD ammo for 12/20 gauge guns in light loads loaded with #2 Lead shot for a while but it never took off in the 12 20 gauge guns. I still have some Federal #2 Lead Special Home Defense loads 2 3/4" inch made in like 2001 or some shit and they only have 1 oz or 1 1/8 oz load of shot in them……….very light load for 12 gauge sporting purposes any way……….normal for TRAP or Doves but not larger game hunting like Goose or Ducks n such that usually required 1 1/2 or 1 1/4 oz shell back then.
    History lesson #1 for today…………………………..Turkey were traditionally shot in the head with a rifle or small bore .22 magnum or LR .22 caliber and if a shotgun was to be used the old way of hunting them was with dogs or on the roost……….you would ROOST FLUSH a Turkey at dusk or dawn and shoot him with Lead Buckshot #4 Buck or Lead #BB shot like a Goose flying at close range. They made it not legal to roost shoot sow the whole rifle head shot thing became shotgun head shot for sporting purposes only……..and safety according to DFWR. So there you have it kids………Turkey traditionally were never shot in the head with shotguns and small shot……..they used rifles or flush shot them off the roost with buckshot.

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