Ok I don't know my ass from a hole int he ground concerning SKSs.
Buddy wants to trade his 25yr old sks for my 870. But his magazine is screwed in?
Are these removable or at least do a conversion on?

I appreciate any info fellas

Also, the mag on it is 30 rounds. If that may mean something.

Keep the mag stock.. you will be happy in the long run.

Standard SKS magazine is non-detachable.  It is possible to convert it to use detachable mags, provided you comply with 922(r), but the detachable mag conversions are not known for feeding reliably.

OP,

There are fixed 20 round Chicom magazines available for the SKS with no 922(r) compliance worries. The 20 rounders have the Chicom Star outwardly pressed on both sides of the magazine.

They install and work like the original fixed 10 round magazines that come standard on the Type 56 rifles, and they are VERY reliable.

I have one and it works great. They also load from stripper clips relatively easy.

Hope this helps.

ETA: Link to Pic

You wouldent happen to have a picture would you? There was no such sks made with a "screwed in" 30 rounder. Someone may have mistaken a law and tried to make the mag non detachable but without pics I don't realy understand what you mean by screwed in...

I too would like to see a picture.

The OP did say that he doesn't know his ass from a hole in the ground, so he probably means a fixed magazine.

The SKS fixed magazine is held in place by the trigger group, and the trigger group is held in place into the stock by a pretty tight fitting retainer.

If it IS screwed in, that would be a first for me.