Question regarding Bren Bolts face

[flightrn]

Greetings All,
I was offered a few Bren bolts (the piece is in the US) and the seller asked if I wanted bolts that have holes drilled in the face of it to vent off the gas. He was told these were modified in case a primer were to become pierced the gas would vent off. Has anyone hear of this before? I would think that it would weaken the integrity of the bolt. What are your thoughts?

Best Regards,
Michael

[woodsy]

The gas holes do not weaken the bolt in any way and were standard production on John Inglis guns.