I have several D&H USGI 30 round mags but because I'm in CA they have 10 round limiters.  Traveling out of state for some training where 30 round mags are legal and I want to convert my 10/30 mags back to straight 30 round mags.  My question is this:  once the limiter is removed, do I need to attach the spring to a floor plate insert for this type of mag (D&H USGI 30 round aluminum teflon mag)?  Or can the spring simply rest against the current floorplate?  I know for Pmags there is an insert, of "floor plate lock" included when converting from 10/30 to 30 rounds, but for the aluminum D&H USGI all I have is the floorplate.  If an insert is needed, I can't seem to find one for this type of magazine, only for Pmags, so any help on where to located these inserts would be appreciated.  Thanks for any help on this.

Spring just rests against the floor plate.

+1

Ah you can't even get those parts shipped to you in Komifornia!  You can't have those parts in your possesion in Komifornia!  And doesn't Komifornia have a law once you take your AR out of state you can't return with it?

I'm the Director of Compliance for a FFL/Gun Range in California, maybe I can shed some light on it.

California bans the manufacture, transfer, blah, blah, blah of "high-capacity" magazines (anything over 10 rounds) but, however, does not ban the possession of said magazines.  So long as you are the original owner of "high-capacity" magazines and you've owned them prior to January 1st, 2000, you may still own and use your magazines.  Should any of your magazines become un-serviceable or damaged, you may legally replace or repair your original magazines using a legally-available "re-build kit."  A re-build kit is essentially a fully-functional 30 round magazine, just disassembled.  So long as it's not built and disassembled, you can openly and legally sell/transfer a re-build kit in the good faith that the buyer is the owner of legally-grandfathered magazines.

You may also use the re-build kits to make "ten-thirty" mags, which are mags that originally started as 30 rounders but are permanently modified to only take 10 rounds.  The permanent part is important to note.  Simply putting a block or spacer in a 30 rounder, then putting it back together is NOT CA-legal because it is not permanent.  The penal code covering high-capacity magazines does not state exactly how it's supposed to be permanently fixed, but it states that it must be permanent.  Some of the methods I've seen are epoxied floor plates on polymer mags, rivets, welds, and other ways of sadly making 30 rounders permanent 10s.  If a cop wants to check, he can try to fit more than ten.  If it even gets to that, most cops will stop there if it only holds 10 rounds.  Some cops in the know, who want to give you a hard time, may try to take the mag apart, and God help you if you didn't permanently secure that mag -especially if you're using it in a bullet-button AR, because then you've just committed a felony.

Going back to the magazines, there is no provision in the law that requires you to keep receipts of purchase for your original mags -it's a toothless law.  There are some restrictions however; you may not use your legally-grandfathered magazines in fixed-magazine weapons, example: bullet-button equipped AR15.  You can legally have an off-list, bullet-buttoned AR15 and you can have your legally-grandfathered 30 rounders, but the second you insert magazine into rifle, you've just "manufactured" an "unregistered assault rifle."  

Vote accordingly to ensure this madness doesn't happen to your state.  Don't tune us out -learn from California's sad times.  The Feds use this state as a proving ground.

Have y'all considered using one of Cammenga's 20 round sliding face mags & opening up the front of a mag well?  You'd have to make it a single stack, but make a cut in the side of the follower, & add a vertical rib...

In so many words, he's saying  1) you cannot convert your 10/30 to a full capacity mag and back and still be legal in California - a blocked 30-round mag is still a 30-round mag unless the block is permanently permanent.  2) You can purchase rebuild kits and assemble them in a free state, but they must be rebuild kits anytime you are in California.  3) If you have any 30-round magazines in your possession, then you can bring them to a free state and pop them in your rifle, but you cannot do that in California without committing a felony.

Thats terrible. If you cant use them in a bullet button AR and you can't own a regular AR, what do you use the 30 round magazines for?

They can have funny looking stocked ARs w/o bullet buttons.  Google images of "Monsterman Grip" and such.  They can't even have thumbhole stocks on those.

Just buy some "rebuild kits" to use out side of our "great" state.  Pmags are reasonably priced and can be disassembled without tools.  Just don't forget to break them down into parts

This, buy standard capacity mags in the free world, just remember to break them down before reentering California, leave your blocked mags alone.