Double Shotguns — BoxLocks & SideLocks: By Scott Mayer

Boxlocks and Sidelocks


When considering double shotguns, you will often hear the terms “boxlock” and “sidelock.” These are the two broad categories double guns fall into and describes where the action lockwork is located on the gun. It has nothing to do with how the action locks up for firing.


Sidelocks have removable plates on both rear sides of the action. Mounted on those plates are parts such as hammer, mainspring and sear. The hammers may be visible on the outside, like on a muzzleloader, or concealed inside like on a modern shotgun. Boxlock guns have their action parts contained within the hollowed-out body of the action.




The argument of which is better has gone on since Anson & Deeley patented the first successful boxlock in 1875. Sidelock fans point out that that it’s easier to remove sidelocks for cleaning or repair, and that may have been a good argument when guns were less reliable and more prone to breakage. More metal remains in the action of a sidelock, so the argument also exists that they’re “stronger.”


Boxlock fans will quickly point out that metal is stronger than wood, and since sidelocks are inletted into the stock and boxlocks aren’t, that boxlocks are stronger. Boxlocks are also less expensive to make, so you can often get a very good boxlock for less money than a not as good sidelock.


With modern manufacturing and materials, the only real practical difference is that sidelocks have more metal surface for engraving, so you’ll often see that more elaborately engraved (and expensive) shotguns are sidelocks. There are also shotguns with “false sideplates,” which are nothing more than boxlocks with fake sidelocks for the purpose of more space for engraving.


–Scott Mayer

Scott Mayer

Writer at John1911
Mayer began his outdoor industry career in 1993 on the NRA Technical Staff where he became American Rifleman magazine first Shooting Editor. Mayer left NRA and entered the business end of publishing in 2003 as Advertising Account Executive for Safari Club International SAFARI Magazine and Safari Times newspaper. In 2006, Mayer was named Publisher of Shooting Times magazine where he was also tasked with launching and leading Personal Defense TV, the first television show of its kind.

In 2008, Mayer returned to the editorial side of publishing, this time in the digital field, as Editorial Director for Guns & Ammo, Shooting Times, Handguns and Rifleshooter online magazines. After a brief stint in 2011 as the Digital Media Director for an ABC TV affiliate, Mayer returned to the outdoors industry and Safari Club International where he is currently Assistant Publisher and Multi-Media Communications Editor.
Scott Mayer

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