Swedish Rolling block - notches

I found at breech block behind the breech block head two notches, does anyone know why they are there?
Please about your advise.

Anyway thanks guys for your advice

https://mira393.rajce.idnes.cz/Swedish_RB/

really no one dont know why are there two notches???

https://mira393.rajce.idnes.cz/Swedish_RB/

Just a guess, but they may be intended to prevent stress risers from forming cracks.

Robert

I don't know that they are really notches, but are a "step" machined at the rear of the receiver where the barrel stub slightly protrudes. Maybe they were formed when the rear of the receiver was machined flat? Here's what it looks like on mine with the barrel installed.
Attachment 312869 Attachment 312870

gas escapes for case head rupture.

Charging clip guides :-P

I'm not sure they have a purpose. They may just be tool runout from machining the rear of the receiver and to provide clearance for the barrel extension.

thanks guys there are a lot of possibilities, (but the most likely may be according to Robert they prevent stress risers from forming cracks....).