Bolt pulling out the rifle when cycling

[rookhawk]

It's coming back to me. The oval shaped bolt release on the left side is on a pivot pin. It keeps constant pressure on that spring you showed. I think the spring has softened which seems like your hunch as well.

 

[rookhawk]

His is SR20 which appears to be conventional lock down bolt.
View attachment 664745

I think the models are SR21 (bolt) and SR30 (Straight pull). Not sure which he has, but either way it doesn't look like the photo you put up. That is an old JC Penney / Montgomery Wards style mauser that was indeed, made by Heym. (but is not like the modern renditions that have unique actions)

PS- it appears they also did make an SR20 for a period of time. It was a private labeled "Mauser 2000" rifle. I've never handled one so I can't comment on that one at all.

 

[UKHunter]

I think the models are SR21 (bolt) and SR30 (Straight pull). Not sure which he has, but either way it doesn't look like the photo you put up. That is an old JC Penney / Montgomery Wards style mauser that was indeed, made by Heym. (but is not like the modern renditions that have unique actions)

PS- it appears they also did make an SR20 for a period of time. It was a private labeled "Mauser 2000" rifle. I've never handled one so I can't comment on that one at all.

Yes, it is an SR20 which they no longer make.

I will also replace the spring as well as file down the boot stop. Cheers!

 

[Ontario Hunter]

I have had a chance to look at images of left side of SR20. It appears the button is pushed down to release the bolt. That drops the bolt stop shaft. If anything, I would think the buggered tip on the shaft would help block the bolt better. The curious thing is why didn't the bolt sliding over the beveled tip wear away that burr? Presumably the tip was beveled so the round bolt would clear it during regular cycling. It appears it has a lot more clearance than is necessary. This tells me the bolt stop shaft may not be fully rising when released. Perhaps this is due to a collapsed spring but that spring really doesn't look very collapsed. The bent top edge of the spring may be causing the spring to buckle under tension and bind against receiver but I kinda doubt it. I do note that one side of the base of the bolt stop shaft is worn shiny from rubbing against retainer. It may be getting hung up. If the spring is weak, it could conceivably jump out of the dimple keeper on base of the bolt stop and bind against the receiver.

I'm fairly convinced the problem is with the spring. Before you try to replace it, you should stretch it out longer to add more tension. I have done this more than once to restore firing pin springs for shotguns. One forum described finding replacement parts for SR10 and SR20 as searching for "unobtanium".

Mauser did not make the SR20. Heym made its clone Mauser 2000.

 

[Nhoro]

I would try a spacer washer under the spring first. Hard plastic or mild steel. Photos distort perspective but that part looks a bit bent to me, both on the round shift and the flat bar. Both in areas I would expect to be machined straight and at right angles. Without seeing that part in action, it is difficult to advise but it seems to me either the spring is compressed or the steel stop is bent or worn or possibly the bolt. A spacer washer- even cardboard will test the spring without any change to any parts

 

[Ontario Hunter]

I would try a spacer washer under the spring first. Hard plastic or mild steel. Photos distort perspective but that part looks a bit bent to me, both on the round shift and the flat bar. Both in areas I would expect to be machined straight and at right angles. Without seeing that part in action, it is difficult to advise but it seems to me either the spring is compressed or the steel stop is bent or worn or possibly the bolt. A spacer washer- even cardboard will test the spring without any change to any parts

This is the problem with coil springs vs leaf springs. Coil springs when compressed can flex laterally causing the joint to sustain lateral pressure when the desired objective is only vertical movement. Undesired lateral friction = undue wear and tear on the joint. Leaf springs allow only vertical flexing = less friction points = minimal wear and tear. This bolt stop design is ... not that great.