I just got my two bags of sten mags in from Tapco. Out of twenty, there was one that was pretty bad off in the rust department. I'll write that one off. But, for less than $3 each, I am not complaining. Half an hour in the blasting cabinet, and they are clean, straight mags, that work.
Maybe someone can answer this though. How is Olympic allowed to "modify" the mags? I assume because the gun can still be used in the sten, if the welds are ground off. But, the BATF considers a welded on brake as being permanent. That's some backwards thinking if true.
Anyway, could I weld the square tubing on myself to the back of the sten mags? Oly does it for around $25 on your mags. I can get a few feet of square tubing, for a few bucks, and cut and weld the blocks for nothing. Hmmm?
Maybe I'll find my local freindly ATF agent and ask about this. I could have one piece Sten mags for the Oly for less than $10, and Oly wants $65 for theirs.