20 Round Star

[Ronin76]

I have a 20-round, fixed Star magazine which I intend to install on an SKS basket case project.

I have heard that these magazines can be unreliable but don't have any direct experience with them. From a mechanical engineer's perspective the hinged follower seems to be a better design than a follower floating on top of a spring - but maybe there's something I'm missing about this set up.

I would like to hear any and all input from people who have had direct experience with these magazines - good, bad, or ugly. Especially if you have had bad experiences which you were able to fix or things to look out for.

I won't be able to try this out myself as 1) the basket case SKS I have is missing the entire gas system, and 2) currently I am not in the US where I have this rifle.

[running-man]

I've not heard that the 20 round star mags are problem children.  As you mention, they are very well built.  I think as with all magazines, the feed lips are absolutely critical towards whether they feed reliably or not.  About the only way you'd really know for certain is by trying it and maybe comparing it to a stock 10 rounder in the same gun.  Sometimes things that have poor reputations simply work, and others that have great reputations just cause problems in certain setups.  Good luck!

[Ronin76]

Yeah, I don't know it for a fact. It's just that I had read on some other forum that the 20 round fixed magazines can be problematic.

As a mechanical engineer it seems to me that these fixed magazines should be pretty good. The feed lips are part of the receiver so nothing really different from the original ten rounder. The follower is fixed to a hinge so I wouldn't expect it to dip or come up in a bad angle.

I am half tempted to rig up an external bolt hold open so I can pop in a fresh stripper clip once ten or more rounds have been shot.

[running-man]

Heh, fellow mechanical engineer!  (keep away from that P32 guy, he's too Chemistry science-y!)

For a BHO, you could mimic what Navy Arms did in the Assault Carbine (the SKSGuide weebly pages are our encyclopedia whereas SKS-Files is our discussion forum):

http://chinesesks.weebly.com/type-84.html

Each fixed magazine body has its own set of lips, they are not part of the receiver as is evidenced by the fact you can't pull out the entire magazine with the bolt closed on a stock SKS.  While they are nowhere near as problematic as say the lips on a detachable AR magazine, I have seen some that do need a tad of persuasion (which is often difficult considering the gauge of metal they used on them!) to guide the tip of the next round to the right spot for good consistent feeding & to eliminate an occasional stovepiping.  Because of this and the tolerances involved in seating each magazine, what fixed magazine works great on one SKS, may not always on another.



I think the ding on the 20 rounders has always been they have such a large range of force exerted from the follower spring that the difference between round #20 and round #1 can be significant enough to cause problems if the lips don't guide perfectly.  That plus being they are aftermarket parts, they were never fitted to a specific rifle at birth like the stock magaines were and the tolerance stackup can sometimes bite you.

[Ronin76]

Thanks for the info and the photos Running-man!

I'm not sure where I got the idea that the feed lips are in the receiver. I'm obviously confused on that part.

Next time I'm back in CONUS I will check the 20-rounder I have to see if it has that "twist" in the follower assembly.

For the bolt-hold-open - I was thinking about adding a button/rod running vertically up inside the rear of the magazine which would push up the stock hold open. No need to modify the action itself, just use what's there. It might be something as simple as just drilling & tapping a hole in the bottom of the hold-open "wedge", then screwing the threaded end of a small rod into that hole (fix in place with a lock-tight-ed nut), and have the other end of that rod extending out through a hole in the magazine body. Nothing too fancy nor complex and use a feature that's already there.