View Full Version : Fancy SxS lingo...I need help...

September 30, 2001, 10:52 PM
Can someone clue me in on what the basic action types are (and the differences between them, on SxSs.

What the difference between a sidelock and a box lock, etc. What the heck is a chopper lump barrel?



September 30, 2001, 11:27 PM
A Sidelock gun has the trigger mechanism (or locks in shotgun lingo) attached to sideplates. If you take the sideplates off you can see the trigger mechanism. Each SXS has two sideplates , one on each side. Sidelocks can be easily recognized by the long sideplates extending behind the breech and usually have several pins or screws on the plates.

Some cheap boxlocks have false sideplates (Like the late but not lamented Remington Peerless). If you remove the false sideplates they do not have the triger mechanism attached.

Sidelocks are a throwback to outside hammer guns. They are considered more desirable and are generally more expensive to manufacture.

Boxlock guns have the trigger mechanisms behind the breech and contained within the "Box" behind the breech. Usually boxlocks do not have sideplates. To remove the "Locks " generally requires the ministrations of a gunsmith.

A "Chopper Lump" is a type of locking mechanism. The barrels are attached to the frame by an underlump under the barrels. Chopper lumps have part of the underlump affixed to each barrel. As opposed to a solid lump attached to both barrels. Chopper lumps can easily be discerned by observing a seam in the lump that divides the lump equally along the axis of the barrels. Chopper lumps are considered more desirable as they apparently take more craftsmanship to make.

Lets see if I can find some photos.

Geoff Ross

September 30, 2001, 11:29 PM
Here is a link to a photo of a sidelock. Actually it is the Baker Batavia Leader, one of the few american sidelocks made.


Notice the long plate extending backward with the several screws in it . this is where the locks are attached. If you removed the sideplates the locks would come off with the plates.

Off to find a photo of a boxlock!

Geoff Ross

September 30, 2001, 11:39 PM
Here is a link to the new A H Fox guns made in New England. Fox guns were among the best made in this country. They are all boxlocks.


Notice there are no sideplates extending rearward of the breech. the triggers or "Locks" are contained within the frame of the gun.

chopper lumps may be more difficult:D

Geoff Ross

September 30, 2001, 11:50 PM
Here is a link to bill Hanus Birdguns. Imported from spain and excellent quality for a modest price. (OK modest by double gun prices)


If you scroll down you will see pictures of how the lumps are attached to each barrel and would be joined to form the underlump to lock the barrels to the action. You gotta see the pictures to know what the hell I am talking about:D

OK K80's tutorial on shotgun actions is finished, if you can understand what I have tried to get across you are indeed an educated gentleman:D:rolleyes:

Geoff Ross