Old Stevens model 5100 20 guage double
A friend has one of these shotguns and when the barrels are closed (chambers empty) the right firing pin "fires" I am looking for a schematic for this gun and cannot find one. I used to have Brownells big book of schematics but it was loaned to my brother and has long since disappeared. Any help would be appreciated.
When I google it, I get shots of a clasic stevens/ springfield/ savage SXS double triger box lock.
I inherided a 16 ga of the same family.
Try googling "stevens 5100 exploded view".
I had no problem finding a diagram for this gun.
Not a lot to go wrong and not to complicated a gun.
Most of this applys to any older mid grade US made box lock.
Basic dissasembly for diagnostics is simple, but its been a while so take this with a grain of salt.
Remove the trigger guard from the stock, and unscrew from the reciever.
Pop off the butt plate and you find a hole leading to a screw that mounts the stock to the reciever.
Pull it loose and you will be able to see the action, intact and functional.
Most likely problems.
Sear is worn and does not engage the hammer correctly - compare left and right sides
Trigger is stuck/ stiff etc and tripping the sear
The cocking system is worn and not fully cocking the right hammer, so the sear does not engage
Debris in the action causing havoc.
Bottom line is you should be able to work the action and watch it dry fire.
The hammers and sears are a bit buried in the box lock, but you should get some idea of the problem.
If the hammer stays put and then jumps, its probably an worn sear.
If it falls and comes back up as you open and close the action, it could be the cocking system or the sear.
If the sear does not move when you cock the gun, look for grime and trash in the action or trigger.
With those observations you should be able to diagnose the problem because you have two actions mounted side by side to compare.
Going very deep into one of these actions is a bit more complicated.
If you dont have the right tools to remove the pins without maring them you might want to pass.
It should come appart by the moron method - knock the pins out and shake.
Getting all the spring loaded parts back in place can also be tricky.
I dont recall ever needing to go very far into mine, so I have no advice on this area.
If you suspect a worn or dammaged sear or hammer, the paired parts are probably symetrical and you should be able to compare them for a positive diagnosis.
Filing and stoning the sear surfaces to improve engagement is not a job for the novice.
If done improperly, the trigger pull will be poor, or unsafe.
Also, these parts are often case hardened and if they are worn out, chances are the case is worn through and the parts may need to be case hardened again to prevent rapid ware.