My new Shoei MG42.

Those draw runners look like the real ones - lol.

The spring is two pieces of woven steel, quite distinct - a little similar to the modern Russian ones.
Original here for $10.00
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=321123620#PIC

Pit.

Yes a main spring would help, but seeing as I'm making a dummy (and not heavy) bolt I think any spring with a diameter the same as the original 25mm [Pit?]???) will work ok - with around 20 windings. A well used real spring I imagine would be weaker and thus not too strong.

Yes, Pit - the drawer runners do look similar to the real thing - a bit narrower though! That's why I thought buying a ready-made pair for a few bucks would save a lot of time and effort (me being a lazy SOB) lol

Ozi, there are only two more measurements I need: a) the depth of the receiver side and b) the diameter of the hole in the shoulder stock where it joins the receiver!

The rest I can work our near enough, though you may have to "fine tune" the installation by filing an odd bit or two!

Kiwigunner

I'm hoping these are the measurements you are after.

I love taking pictures, so it's the easiest way to make sure we are talking about the same thing.

Just a little under 40mm deep to the centre. The bottom is slightly curved as shown.
I can't really take a measurement on the sides, because it is curved from the base.



The hole in the stock is very close to 30mm.



My camera is still ready and charged if you need more info or pics done over the weekend in daylight.

I figure you might have already seen these blueprints etc on a Photobucket page.
https://s7.photobucket.com/albums/y270/droolingidiot/Diagrams/#!cpZZ1QQtppZZ24

Thanks Oziguns - that's just what I needed to check!
The blueprints are very clear in some places, and because Shoei make most parts off-size in some way I needed to see your gun's measurements!

Let me know if you can locate a spring - I've realised it needs to be much lighter than a real one because the dummy bolt wont weigh anything like the real bolt - and if the spring is too strong it will smash the dummy bolt hard into the chamber!

Maybe get several if they're cheap enough, and try them each to see which works best!

Kiwigunner

Thanks Mate.

Yep I should be able to get a spring. In fact, that's exactly what I did when I needed a spring for my M16.
I went to the spring works, searched through some boxes, and grabbed a few for $1 each. One of them was perfect, the other couple are somewhere in my shed.