View Full Version : I need to rebuild my old AR magazines. Questions

05-23-2012, 8:50 AM
I have several old pre-ban 30 round aluminum magazines that I have been using in my featureless AR for some time. I've owned these since the 80's. They are wearing out and I need to rebuild them. I was thinking on using Promag rebuild kits as I want to get away from metallic magazines. Am I breaking any laws by going from metal to plastic magazines? Thanks.

05-23-2012, 8:53 AM
Learn the difference between rebuild and repair. The minor difference in nomenclature is even more profound than the difference between magazine and clip.

05-23-2012, 9:06 AM
I belive the generaly understood concept is that if you start with one standard cap mag, you must end up with one standard cap mag.

There is no provision for using all or any of the original parts as far as I know, I am digging around for a reference, but I cant find a clear one.


In a letter dated November 10, 2005, Deputy Attorney General Alison Merrilees answered a list of questions about the legality of repairing and replacing parts of legally possessed large-capacity magazines.

The letter clarifies that it is legal to replace parts of a legally possessed large-capacity magazine with parts of any vintage. It also states that the possession, sale, or import of all the parts of an otherwise prohibited large-capacity magazine is not illegal though assembling them into a new large-capacity magazine would be a crime.

The general rules regarding magazine repair appear to be that as long as one ends up with the same number of legally possessed large-capacity magazines, has a plausible path of replacement parts from the original possessed large-capacity magazine to the repaired magazine, and the magazine continues to work in the firearm it was originally designed to operate in, one would not be violating the law.

There are no restrictions on modifying a legally possessed large-capacity magazine to work in another firearm as long as the magazine continues to operate in the firearm it was originally designed for. This concept, however, has not been tested - 'appear to be' is all we have.

If it was me, I would keep the old worn out parts (not assembled) as insurance or whatever. I also cant find anyone using rebuild/repair as anything but interchangeable.

Here is the AG's letter from 2005... He does seem to make a distinction between repairing/rebuilding an old magazine, 'replacing' an old magazine with a post 2001 new one and manufacturing a new one. You already lawfully posses a certian number of standard cap mags, you should end up with the same number, not buy a new mag to replace (different from repair/rebuild) an old one or build one more than you own now (manufacture). Buying a repair kit to rebuild an existing magazine is not 'manufacture' and the new parts do not 'replace' an old magazine with a new one. If you were to straight up buy a 30 round Pmag and break down your old mag, I guess that would be illegal, although you still end up in the same place. You have to build it out of a repair kit, effectively replacing parts on your old mag untill they are all gone. I think its about the path you follow to get there.

I am sure someone else will clarify.


05-23-2012, 11:23 AM
that sounds overly convoluted. my understanding was that complete replacement was ok provided the defective mag was disassembled and taken out of service. the lack of a requirement that ANY of the old mags parts be reused would tend to reinforce this.

BTW, to the OP, copes only adds $1 to ship a mag as a kit. $9.95 flat rate shipping. great folks.

05-23-2012, 12:05 PM
If its convoluted, its because thats the way the law is written and interpreted.

I dont have enough imagination to make this stuff up....

Replacement and repair are two different things, one illegal, one not, according to the AG letter from 2005, even though they have the same outcome. Hair splitting possibly. I would personaly still start with a repair kit and work my way up, rather than buy outright a new 'replacement' mag.

I am suprised there isnt anyone with more experiance to post a comment. My standars caps are all steel, and in new condition. I have never had to repair them or rebuild them, but I given it some thought.

05-23-2012, 12:44 PM
Go with Pmags not ProMag. The quality is way better. The standard spring from a metal mag will work in a Pmag. Do it like this:

Day 1: replace everything from the old mag with Pmag parts except the old spring.

Day 2: replace the spring.

Mags legally rebuilt.

05-23-2012, 4:27 PM
Go with Pmags not ProMag. The quality is way better. The standard spring from a metal mag will work in a Pmag. Do it like this:

Day 1: replace everything from the old mag with Pmag parts except the old spring.

Day 2: replace the spring.

Mags legally rebuilt.

+1 go with PMags

05-24-2012, 1:36 PM
It's Theseus' ship. (not the user here, but the old philosophical quandary).

So long as the end result is that your pre-existing magazine didn't magically become two magazines, then your replacement of parts is probably good. To show a process trail of continuity (keeping the ship still the ship as much as possible) some advise that you leave one of the old parts in as an intermediary process, thereby establishing that your new parts constitute the "old magazine", then swap the final old part so that your "old magazine" is made entirely of repaired, replaced, or upgraded parts.(a legally owned large cap mag is a legally owned large cap mag, you can upgrade it to a larger capacity along this repair chain if you wish - The follower is a nice easy intermediary part to retain and is often compatible with many bodies)