What would 14" shotguns be like? 12"? 8"?

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Dr_2_B

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This is a rhetorical question because legal restrictions here in the States require longer barreled shotguns, but I would like to know from some of you guys who live and breathe this ballistics stuff. How effective do you think short or very short shotguns would be? And at what range? At what range would they become useless?

I guess we're talking about the lupara we've seen in movies. Anyone have any real life experience with these very short shotguns?

Please. I'm not advocating sawing a shotgun below legal lengths nor am I advocating any other illegal activity. The consequences are too high for such choices.
 
I have handled a 14 in to much fun but you do loose capacity of shells need to remember
to do tac reloads when shooting great as an entery weapon.
 
Um... all you have to do to lop your shotgun down as short as you please is send $200 BATFE's way. It's only a rhetorical question if you have no intention of ever doing so yourself. :)
 
Most shotgun powders burn fast, that is why you can use them in some pistol cartridges.
Shotguns work on low pressure, and have very large bores for their relatively small powder charge, this results in a lot of surface area to burn when hit by the primer sparks, without a very high maximum PSI to reach.

A lot of the powder is burned in the first 6-8 inches with many powders, and by 12 inches you would see the majority of the velocity.

This of course is based on the burn rate of the powder, slower may benefit from a longer barrel.


In reloading you will find that heavy rounds for a given caliber lose the least "energy" from a reduced barrel, because they can build up to the peak pressure in less room. While high velocity light rounds benefit greatly from added barrel and lose a much larger percentage of energy as you remove barrel.
Shotguns put out huge payload at relatively low velocities, and so likewise need minimal barrel to reach or maintain peak pressure.
Old black powder shotguns needed more barrel because black powder burns slower.



A quick search and I noticed a lot of data for over 18" but not as much for under, obviously because fewer people have NFA firearms.

One of the top google finds was this guy using a chronograph, his post is filled with a lot of profanity, which unfortunately detracts from the otherwise useful information:

http://forum.saiga-12.com/index.php?/topic/19103-barrel-length-vs-velocity/

Without the added profanity here is the chronographed data:

birdshot- 12 gauge, 2 3/4 inches, 1 oz shot
12" barrel average FPS- 1040
14" barrel average FPS- 1069
18" barrel average FPS- 1114
19.5" barrel average FPS- 1114
20" barrel average FPS- 1108
28" barrel average FPS- 1159

Then using Remington 00 Buck-
12" barrel average FPS- 1121
14" barrel average FPS- 1127
18" barrel average FPS- 1216
19.5" barrel average FPS- 1205
20" barrel average FPS- 1182
28" barrel average FPS- 1250


This variation coincides with another graph I located on THR posted when someone asked a similar question:

attachment.php


(posted in case the image disappears) 7" is about 1150FPS, 8" it is about 1175FPS, and 9" it is 1200FPS, by 12" it is about 1350 FPS, by 18: it is over 1400FPS, and from about 20-30" (with 20" clearly an anomaly or severely backbored barrel or with a choke issue going on) it stays around 1500 +- 100FPS and some margin of error.


So for as handy and portable as the short barrels are they give up little with typical powders. The main benefit in hunting uses is a certain length swings better for people and makes hitting small moving targets at a distance much easier.
The long barrels do dramatically decrease the decibel rating as well, a few inches makes a huge difference in the sound category, not just slight but huge.
The perceived muzzle blast is also greater the closer the bore is to your face. The shorter the barrel the closer you are to the bad side.
 
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The agency I worked for had 14" 870s. They handled and shot okay and the shorter length made them a bit handier, moreso when getting of a car. However that 4" of barrel in a 18" allows the powder to burn more thoroughly. The 14" barrel produces a significant muzzle flash compared to a 18" with full power loads.
 
The ballistics side of it has been covered well here, good info. As I suspected, not much is lost in the short tubes.

I built a 14" 870 and liked it so much I decided I just had to have an autoloader as well. I finally located a factory 14" barrel for my Benelli M2, and modified the bolt carrier to allow ghost loading. What a great little camping/house gun, fast handling yet very 'shootable'. Fully topped off, she holds 7 rounds.

THEN, I walked into a gun store a while back and ran across a 14" factory 590A1 on the wall.....so now I'm up to three of the dang things.

That's the 'only' disadvantage I've found with the shorties....mag capacity. But the trade off is worth it to me in most cases.
 
I have a 12.5" 870, it's extremely handy and as mentioned you don't lose too much ballstics on paper but there is a slight but noticable difference on target media.

Full power buck and slug loads from this gun seem to be about half way between regular and reduced recoil loads in general effect on various materials. Also as mentioned, its LOUD and BLASTY.

Regardless, I believe that most defensive style shotguns would be sold in the 12-14" bbl length if it weren't for the legal restrictions. It just makes more sense on a CQB/animal defense tool than the battle rifle length affair that is your typical tactical shotgun.
 
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Short

Wanting to avoid the fuss with the ATF, etc. and, yet, having a desire to play around with a short barreled shotgun (since there is little else you can do with one other than play around) and having a long time interest in muzzleloaders, a couple of years ago, I bought a Blunderbuss, a 14 gauge flintlock with a 14" barrel.
It is a hoot to shoot......the blast and smoke are right there not terribly far from your nose. I patterned it with 00 buckshot at 10 yards. The pattern was about the size of my hand; all pellets hit.
Great fun, although somewhat slower than a modern pump gun.
Pete
 
Oh, like this?

Ironically, same category as 28" unit in Canada if it came with that barrel length from the factory.

Sure is handy...
 

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Zoogster,
You seem pretty knowledgeable so I'd like to ask you to speculate on range info. I realize you probably don't consider yourself an expert, but I'd still be interested in your thoughts because you've obviously studied this more than I.

What range would you consider to be max for, say, a 20 ga 18"?
What range for the same load 12"?
What range for 8"?

send $200 BATFE's way
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Gord, thanks. I never have considered getting the tax stamp thing, that but I suppose I could do just that.
 
That's the 'only' disadvantage I've found with the shorties....mag capacity. But the trade off is worth it to me in most cases.
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An 8 inch shotgun would be like going to a gun fight with a derringer, alot of reloading.
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Well, that depends on the shotgun in question. I've been thinking very hard about getting one of these lately.

View attachment 549741

S17-8inchLrg3wg.gif
 
I've fired 14" barreled 870s. LOTS of flash in low light. Otherwise, just like an 18" version.
 
Dr_2_B I most certainly am no expert, there is some very experienced individuals in these forums with more time with guns than I will ever have. People with larger firearm and ammunition budgets and more experience in using them. People that spend more time in states that allow cooler toys.
I benefit tremendously from my ability to comb through their experiences and combine them with my own.

I personally have only limited experience with using shotguns below 18". While there is people on this forum who own multiple short barrel shotguns.
I will defer to them.
I do understand the burn characteristics of powder. I also know the decibel level of shotguns changes dramatically with just a few inches of barrel loss or gain.A consideration for a self defense setup likely to be used without hearing protection.
But I do think most self defense shotguns would be closer to the 12" barrel size without the NFA restrictions because they are so much handier and easy to maneuver, or even carry slung in the outdoors for protection from large predators.


Based on the data you could probably factor the percentage of lost velocity and get a general ballpark of lost range over a typical length with a given size shot. You can use various ballistic programs or charts to make it easier. It shouldn't be too great since the velocity losses are not great.
Faster shot also loses velocity more quickly, and then velocity loss stabilizes, so shot that starts out much faster typically isn't that much faster after some distance than shot that started out somewhat slower.
At close ranges the difference can be more obvious, but you are still talking.


I think really short barrels can tend to open up faster for a given choke. Many claim this is not so, but it does appear to happen, and so I would venture a guess that the still expanding gases and burning powder venting (and contributing to greater muzzle flash) while the shot column exits can cause the shot to open up more near the muzzle than when a longer barrel allows things to stabilize somewhat before it exits. That is a purely hypothetical though.
Such an effect is negligible compared to the effects of a choke.


I think the biggest limitation with a short barrel is sight picture and ability to swing through a moving target. If you can still aim it without much problem then the range shouldn't be reduced much. Choke will be the main determiner of shot density.
Each barrel, choke, shot size, and ammo combination can have different patterning at different ranges. A smaller choke can reduce birdshot pattern size and yet increase buckshot size because of more deformed shot for example. The ideal choke or lack thereof depends on the projectile you want to have a certain size pattern with at a given range. Some premium ammo types are even known to give such small groups without much choke that they can defeat some of the benefits of a shotgun not opening up enough at shorter ranges.
The pattern density and size along with the velocity determines effectiveness at a given range.

As with all shotguns it must be patterned.
You could certainly design a shotgun to work best with a given load for at a given range. Maybe some other posters will give some examples of very short barrel, ammo, and choke combos.
 
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Maybe some other posters will give some examples of very short barrel, ammo, and choke combos.
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That Blunderbuss to which I referred earlier is cylinder choked. It actually patterned tighter than I expected. The textbook stats for a cylinder choked gun, regardless of gauge, is that the pattern will open at a rate of two inches per yard (FC is one inch per). As I noted, the buckshot pattern was way tighter than the predicted 20 inches (and that was without modern modern cases and wads.
Pete
 
I have a 14" barrel for my 870 and it doesn't get used unless I have a specific need for a compact gun. Muzzle blast and flash are such that I much prefer the 20" barrel.
 
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