Some Shotgun Terminal Ballistics Questions

General Firearms Terminal Ballistic Information
1
  1. How does barrel length affect shotgun terminal ballistics? Obviously, things like fragmenting 223 rounds are very negatively affected by shoter barrels. Does this apply to shotgun slugs/buckshot within “shotgun range?”
2

Barrel length being shorter (all else being the same) can give lower velocity, more pellet spread and more recoil. Frangible rounds would not be something I would personally use for anything against a human threat. I was not aware there were breaching rounds that are buckshot… that would not seem like a very effective design.

Can you elaborater on what you are asking and what you are really wanting from us here???

3

Let’s see… to elaborate:

I understand that having a shorter barrel leads to lower velocities. Does having a short barrel (say about 10") in a 12ga lead to drastically reduced terminal effectiveness against a human target at CQB distances? Basically, I’m just trying to figure out if a SBS is worth having/what kind of effects on target you get.

As for the breaching rounds, I was thinking something ridiculous. I had read something and misunderstood it. Once I went back and re-read it, it makes sense now, so that question is moot.

4

Shotguns lose very little velocity with barrel lenght, due to the low charge of powder vs bore size.

I don’t remember the numbers, but I wouldn’t expect any significant deterioration of muzzle velocity of a 10" vs a 18"+ barrel.

5

At typical shotgun distances of 25 yds and under, a shorter barrel does not change things dramatically–you still have relatively low velocity pellets spreading out and impacting the target.

Breaching rounds can indeed be fatal, as seen in several OIS incidents where the breacher engaged an unexpected threat with a breaching round at close range; I was involved with a case where an officer used a Deftec TKO #22 breaching round to fatally shoot a suspect about 15 feet away.

6

Thanks a lot, Doc. That’s exactly what I was wondering about.

7

…in a paper by german ballistic researchers they found that a Dynamit Nobel’s 12 Gauge 31 grams Brenneke slug velocity drop from a barrel about 28 1/3" long and the same barrel shortened to about 14 1/5" was about 30 m/s…from 430 to 400 m/s…

I guess things are not so different using pellets…the velocity drop seems to be very low…

All the best
Andrea