Hudson Sten mkII bolt question

OK guess this might require someone with their own personal x-ray machine

Does anyone know how far back inside the bolt the steel pin in the bolt face goes????

Just trying to think of a "simple way" to make just the bottom two "cart pick up" prongs from steel in the zinc bolt,
Idea is a steel insert replacing these, but need to know how far above mentioned pin goes to see how far back fixing screws need to be.

cheers

The pins are removable on some of the hudson bolts

Please can someone help me work out the logic of this removable pin/spring setup!!

With spring in as shown in 8aces photo, all it does is stop pin from coming out a bit through the threaded part with a hole in, OK fair enough you do NOT want the pin coming out as it will cause feed issues etc...

BUT why????? is it there at all and not just a solid rod as normal????

ONLY thing I can think of is with appropriate "spacer" behind pin it would give facility to adjust height at face of the pin....BUT WHY????..."fixed" pins that sit too proud of bolt face and dent carts badly......
Does this make sense

Please give me the real reason or an explanation that makes sense:)

Maybe they deemed pin to be a user-replaceable part, easier to swap in case of problem than whole bolt?

Edit: it does not make sense, I thought it's a kind of a firing pin that replaces some fixed one.

I've no idea i've seen it on a Sten and Thompson bolt

I did ask the question some time ago
https://mp40modelguns.forumotion.net/hudson-m1a1-thompson-f19/thompson-bolt-identification-t1326.htm

Thanks for the link, did not spot that one
I am fasinated by that pin............

How strong is that spring?

If weak, maybe pin moves due to inertia...