Anyone have any idea how the small pin that sits between the barrels is supposed to work?.It is for adjusting the point of impact of the bottom barrel I would say, but how it actually works is not at all clear.

It's eccentric, and as you turn it, it is supposed to bend the under barrel somewhat, bringing the POI up and down. It works on some guns but not others, and I know people who put spacers under the roller to achieve the desired effect.

BTW check out how TechKrim, another Izhevsk maker, treats the MP-94 regulation module on their guns.

(more in the blog https://sportingbookworm.wordpress.com/ ... #more-3816)

I once read that the guns had varying sizes of adjusters that could be use to tune the regulation and the US importers didn't receive/order any extras.

May or may not have been true. The thin barrel basically flexes up and down on the 94s.

The IZH 94 "SEVER" is a little different. it's a 20ga with a 22 or WMR barrel on top. They have no regulator other than pressure from the upper wood handguard. I hunted quite a bit with a 22wmr version.

The captive pin on my one just rattled around in its slot.....I would say it was supposed to have some sort of wedge or spacer installed that were obviously not installed at assembly.It annoyed me so being a machinist I just made up a spacer out of hard brass to fill in the void,it is a firm fit but does not apply any pressure it just fills the spot.The gun is not a target rifle anyway its only for close range use with the open sights for my purposes.