Definitions & Performance

Shotgun - Any smoothbore firearm that contains a shoulder stock, and fires fixed ammunition that the BATFE has designated as shotgun ammunition.  If the caliber of the firearm exceeds .50", the ATF can, at their discretion, or by order of the Attorney General, classify certain shotguns as destructive devices (DD), due to their having no legitimate "sporting purpose" in the eyes of the government.  The Federal Transfer Tax on a DD is $200. 

Short-Barreled Shotgun (SBS) - Any firearm, as described above, that has a barrel shorter than 18" in length (as measured from the face of the closed bolt to the end of the permanent muzzle), or has an overall length less than 26" (in the case of folding stocks, this measurement is taken with the stock opened). The Federal Transfer Tax on a SBS is $200. 

Performance - Not a great deal of experimentation has been reported on the relative performance of SBS vs. conventional shotguns.  The data that are available indicate three common effects of shortened barrels - reduced velocity, expanded shot pattern, and decreased accuracy.  The degree to which barrel length impedes these areas of performance is dependent upon the type of ammunition, the actual length of the barrel, the choke, the sighting system, and the style of shooting.  For barrels greater than 12" in length, expect an average gain of approximately 10 FPS per inch.   For barrels less than 12", anticipate an average loss of 50 FPS per inch.   This increased loss rate is attributed to excessive amounts of gas being expelled into the air before peak chamber pressure is achieved.  Expanded shot spread may be due to two factors, those being the larger bore area in the first 20" of barrel, and the loss of any bore restriction (choke).  With many barrel designs, the bore is gradually reduced until near the muzzle, where further restriction is achieved by either a fixed or removable choke.  Barrels that are shortened after manufacture will have "open chokes", which is to say the bore has nominal restriction.  This may minimize shot deformation, which can improve pattern uniformity, but the lack on constriction will allow shot to spread more rapidly.  At ranges under 25 yards, the effect is not usually significant.  For longer range shooting, this effect can be mitigated in barrels capable of being threaded to accept removable chokes.  For example, a 12.5" Remington 870 fitted with a full choke can produce patterns comparable to the same gun fitted with a fully choked 30" barrel.  The accuracy potential of a SBS, thus equipped, is limited only by the sighting system, shooting style, and skill of the shooter.  A standard bead sight provides a point of reference for aiming, but due to the shorter sighting plane, engaging targets beyond 25 yards may prove much more difficult, especially if shooting at flying game.  In addition, shooting style will need to be adjusted due to the reduced 'swing' of the shortened gun.   Ghost ring iron sights, scopes, or other aiming aids will allow for precision shots with slugs at ranges well in excess of 100 yards.  These same aiming devices are effective on turkey, but not suited to wing shooting.  For personal protection and security work, the SBS is without peer in the more confined spaces of a home or building.   It also makes a handy dangerous game gun when camping or hiking.                           

(Left) A customized Remington 870 SBS with Speed-Feed pistol grip stock, 14" barrel, ghost-ring rear sight, and one-round magazine tube extension cap.  (Right) The same SBS fitted with a Tac-Star rear pistol grip, Sure-Fire light grip, 12.5" ported barrel, and standard magazine end cap.  Aside from the fact it can be fitted with a shoulder stock, it looks identical to a Remington 870 pistol remanufactured into an AOW.