Benelli M3, No locking chamber?

[doctorhumbert]

I've noticed that my new Benelli M3 bolt does not stay locked, like Remington 870, when round is chambered in a pump mode. Is this normal? Also, will chamber stay locked after firing?

bolt stays closed, but forearm doesnt

 

[pbhome71]

I don't think that is normal. However, I can check mine tonight.

When you said "stay locked", did you mean that the bolt head did not rotated and locked into the barrel recess?

-Pat

 

[doctorhumbert]

Well, chamber is locked to a forearm when in pump mode, and the bolt head locks in to the barrel, but isn't forearm suppost to be locked forward as well? I haven't fired M3 yet, but looks like whole forearm would cycle back along with the bolt when shot in pump mode.

I can pull the shell out from the chamber without pressing the unlock mechanism, and by pulling the forearm since it isn't locked

If recoil from sem mode is enough to push unlock and push back the bolt, isn't it enough to push the whole bolt along with a forearm?

 

[pbhome71]

I'll check it out when I get home.

I think I tried the pump mode awhile back. While retracting the bolt will move the forearm, shooting the gun won't move the forearm back.

I'll if I can explain this better when I get home.

-Pat

PS:[added later] I have not found any need to use pump-mode, yet. I tried several 12ga loads in my M3, and all of them cycled perfectly. Here some of the list that I remember:
- Remington 00buck
- Remington Slugger
- Remington Tactical 00buck (less recoil)
- Wolf #4buck
- S&B 00buck
- PMC #8 light target load

 

[pbhome71]

I checked mine out. The forearm, when in pump mode, did not actually lock. However, the hook underneat the forearm catches the ring underneath the barrel. This prevent the barrel and the forearm from sliding freely.

From what I understand, the bolt's design such that moving the bolt body backward will rotate the bolt head's cam. When the cam rotates, it unlock itself from the barrel locking recess. Chamber's pressure acting directly to the bolt head won't rotate the bolt head - which prevents the whole bolt assembly to go backward when fired.

It probably help with pictures. I'll see if I can take some.

-Pat

 

[doctorhumbert]

Thanks!