On reading this thread I had a Profound Revelation(TM):

[url]http://www.ar15.com/forums/topic.html?b=1&f=5&t=141719[/url]

I take it that UNMODIFIED standard M16/AR-15 magazines (30-rounders) are used as 10-rounders for .458 SOCOM.

If one were to hypothetically manufacture 10-round magazines intended for the .458 SOCOM, what would one have to do to cover one's posterior so as to stay out of trouble for building something that someone else MIGHT illegally use as a 30-round .223 magazine?  Mark them as ".458 SOCOM only" for example?

Good idea, if they had a different follower i could see that being legal. After all, you can fit and feed 14 rds of 9mm through a Glock 19 with a 10 rd glock 23 (.40sw) mag, and this is BATF legal.

Well the mag is legal, doing this is not[;)]

I suppose no FFL holders would be willing to ship them to Californistan either.

Thanks for the v-slap in the face Troy.  I needed that.

[argue]

JUST A GUESS --- but i dont think a USGI contractor would even touch these mags, even if they used preban 100% legal mags, nor would they get involved even if the gun owner were to ship his legal mags to be converted -- reason = theres no money in it for the contractor, not enough 458 socom owners to make it worth while for a large bidness, a small dealer might do it.

what would it take for a 458 socom dealer to sell a person some kinda of home conversion kit? a socom dealer could probably also convert a customers mags for them, there would be money in it for a socom dealer, but not enough for a large contractor to get involved. Maybe? yes? No?
the socom dealer could probably get kalif DOJ approval to re-import the mags (after submitting a sample), converted with a "458 socom only" stamping.

ive seen a guy at the gun shows selling AR and glock hi cap mag bodies, no DOJ agent has hassled him yet.
another guy got DOJ approval to sell yugo 59/66's in kalif.