View Full Version : Shot size differences

August 26, 2007, 01:47 PM
Does anybody have any ballistics regarding shot size differences. Penetration, long range energy, etc,? Assuming both buckshot and birdshot. Thanks.

August 27, 2007, 01:42 AM
and penetration.

For bird shot, subtract the number of the shot from .017 gives the diameter.
Under a priciple of physics, the energy of a shot column is equally divided with the number of items.
So as a example, if the energy of a shot column inside the wad at the moment of leaving the muzzle is 100 ft-lb, and there is 600 pellets in the 1-1/8 onces load, each pellet then carries 1/6 the energy.
Now if a larger shot is used and it uses 300 pellets for the same weight, the energy is 1/3. the larger then has more mass/weight with higer energy to carry farther.

August 27, 2007, 04:37 PM
Like dove and quail, I've tried #8s and #7.5s. The #8s seemed slightly easier to hit with, but the #7.5s clearly killed birds better. I had to "twist" many more birds with the smaller pellets, despite there being more of them in the pattern. With the bigger pellets, most birds were either "DBI" (Dead Before Impact) or cleanly missed. With the #8s, even well-hit birds (based on feather damage and breast condition) often were not killed quickly. As a sportsman, that didn't make me happy, so I went back to the #7.5s.

The owner of my favorite gun shop uses #6s on all birds for just this reason, but he's a better wingshot than I am. You have to find the best tradeoff between pattern density and killing power for the birds you hunt, the ranges at which they're flying, and your shooting skills. For me, now, that's #7.5 shot.

One of the biggest problems with shot larger than #7.5 is that most ranges won't let you shoot with them. That's a problem, because you really need to practice with the loads and the gun you're going to hunt with. Yeah, you can practice gun mount, target focus, lead, swing, and the rest of the mechanics of wingshooting no matter what you put in the gun, but different loads really do perform differently in the air, and it takes both the pattern board and the shooting line to really know that your loads are working. And even then, dead birds are what really tell the tale.


August 27, 2007, 04:55 PM
Here's a great resource for shot shell info:


nutty ned
August 28, 2007, 09:18 PM
cnx post

August 29, 2007, 05:42 AM

Not being rude but your math doesn't work out. The subtraction of the shot size number from "0.017" doesn't give the shot diameter in millimeters nor is there any shot that is smaller than 0.050" (#12). Also, if you have 600 pellets leaving the muzzle with 100ftlbs of energy, each pellet only has 0.166 ftlbs of energy - to obtain the 1/6 value you stated, you can only have six pellets in the load.


Shot pellets are nothing more than small "round ball" projectiles and they loose energy very quickly from air friction. The weight of each pellet increased disproportionally to the amount of diameter increase meaning that a small increase in diameter gives you a higher weight gain. The heavier each pellet is, the more energy it will carry for over a given distance because it will maintain more velocity. Thus, if you compare the same weight shot payload launched with the same exact muzzle velocity, #5 shot will have almost three times the amount retained energy at 40 yards as will #7.5 shot. Likewise, at 40 yards, #7.5 shot has about 30% more energy than does #8 shot.

Pellet count doesn't mean squat, all that matters is how many pellets in the load are actually effective. As tube_ee brought up, lots of people choose #8 shot for doves because of the higher pellet count and the result is many doves are wounded and never recovered. Reason being, the higher pellet count means you have a longer shot string and with it comes a disproportional decrease in the number of effective pellets. When you pattern for wing shooting, you cannot use a stationary patterning board because it doesn't give you an indication of "effective pattern density". Thus a 1oz load of #8 shot containing 410 pellets may produce an effective pattern density of 20% while a 1oz load of #6 shot containing only 225 pellets may produce an effective pattern density of 40% at the same range. This boils down to mean with the #8 shot, only 82 pellets are actually within the effective pattern while the #6 shot is placing 90 pellets within the effective pattern. Additionally, the amount of retained energy is considerably higher with the larger #6 shot so even if less pellets actually strike the intended target, they are more likely to produce a fatal injury because of their greater penetration depth.

August 29, 2007, 08:18 AM
.17” minus the shot number in hundredths is the diameter of the shot in inches. For instance, .17" minus #7 would be .10".

From ammobank.com


August 29, 2007, 09:28 AM
I would not expect to subtract from inch measurements (0.017) and end up with mm??

Thanks for the picture.

August 29, 2007, 10:16 AM
This might have what you are looking for.

August 29, 2007, 04:39 PM
The gaps between 8, 7.5, 6, 4 and so on. I've always used remington expess long range #4 in a 12 gauge for rabbits, crows, partridge. Lately Iv'e been using a 410 and 20 gauge with #7.5 shot and was wondering if i was really losing that much performance. But by the charts from ED21 I'm hitting about half as hard. So does two hits from #7.5 compensate for the one hit of a #4? I guess if the smaller shot fails to penetrate it's better to have 6 solids hits from a larger size than 16 hits of the smaller.

August 29, 2007, 06:27 PM
For velocities the Federal website lists velocities with all their shotgun loads. Some of their buckshot loads are running at 1325fps.

August 29, 2007, 11:19 PM

The unit of measure was not indicated in the post I referenced, metric system uses decimals too and there is a 0.100" difference between 0.017" and 0.170" Typo error is fine, happens to everyone, it just didn't work out as written.

I wasn't being rude in my reply, even stated such ... there's no need for you to be.

August 29, 2007, 11:25 PM

Am I missing it somewhere or is the "test barrel length" omitted from the Federal shotgun ammo data tables?