Unknown function for Mauser screws.

[Rob]

I have an old British Mauser sporter with two machine screws on either side of the bolt groove at the rear of the receiver. They penetrate the thickness of the steel but go no further. They seem to have no function. I have never before seen screws in this position on a Mauser. Any ideas?

 

[trevj]

If that section of the tang is flat and relatively parallel to the bore, I would suggest that the screws are blanking off the mount holes for a rear peep sight that was installed there in the past.

 

[Evanguy]

Edit, sorry I was thinking of the screws being side by side not in line.

 

[tiriaq]

I wonder if they were for eliminating play in the bolt sleeve when a cocking piece sight was installed?

 

[guntech]

I have an old British Mauser sporter with two machine screws on either side of the bolt groove at the rear of the receiver. They penetrate the thickness of the steel but go no further. They seem to have no function. I have never before seen screws in this position on a Mauser. Any ideas?

Weirdest placement of screws... I have seen a lot of drilled and tapped screws on Mauser's... never ever seen this before... a puzzle for sure. Nothing can be mounted there... I go with the "eliminating play in the bolt sleeve" possibility.

 

[highlander]

Yep, I've seen them once before on a Mauser, but like everyone else, I've no idea what they are for or why they are there.

 

[bearhunter]

You don't mention how far the screws protrude, if they do, below the action.

They may be an off the wall way to stabilize the rear portion of the action in the stock? Or is there a possibility something is missing from the underside of the action which was attached for the purpose, say to stop horizontal play or act as another recoil lug?

If it were for one of these purposes, the screws you show would now likely just be fillers for the holes.

I've never seen holes drilled there on any bolt action, other than in your pics.

 

[bearhunter]

I wonder if they were for eliminating play in the bolt sleeve when a ####ing piece sight was installed?

They appear to be flush with the action tang surface.

 

[guntech]

They are flush with the tang surface now... but maybe these are simply filler screws doing nothing but filling the holes...

 

[9.3mauser]

If the rifle originally had a c o c king piece sight, they may be there to take some of the play out of the shroud to improve accuracy. The flange of the shroud would sit right where these screws are.

 

[Potashminer]

Another possible clue? - look at the trigger sear and cocking piece ledge - I had read old-time effort for those cocking piece sights was to file or grind the sear and ledge to a "V" shape - in effort to come back to identical position for each shot - might go with the idea of trying to stabilize that shroud. As above - I have owned and worked with at least a dozen Mausers and never seen screws like that - I really have no clue what they might have been for. Do the threaded holes protrude completely through the receiver (out the bottom) or are they "blind" holes - dead ended within the receiver?

 

[hunter5425]

No idea what they do but I hope that auto censoring "male chickens" gets remedied soon.

 

[CGS]

No idea what they do but I hope that auto censoring "male chickens" gets remedied soon.

Pain in the *ss, isn't it.

 

[Dosing]

I want to say for a subcaliber adapter, like a 4mm, but I could be wrong. Like the others I saw it only once on a rifle along time ago. Any idea who made it?

 

[Rob]

If the rifle originally had a c o c king piece sight, they may be there to take some of the play out of the shroud to improve accuracy. The flange of the shroud would sit right where these screws are.

Yes.

From Gunboards:

"The 2 little screws are for supporting the bolt shroud when the bolt is closed.
The Mauser bolt shroud generally has some up&down play in it. When a Bolt Peep sight is used, it was somewhat common to install the screws or sometimes just pins in that position.
Then trim the heads/ends down so the bolt closed smoothly but with minimal clearance on top of the screw heads/pins. That insured that the bolt shroud w/ bolt peep rear sight attached would always end up in the same aiming position with each shot and not rocked to one side or the other. Or up or down."

Thank you all for the input.