Hello everyone.  I’m looking for suggestions on how to make 20 and 30 round mags legal for NJ use.  How would you disassemble these mags.  I’m new to the AR world and will feel extremely stupid if it is a matter of twisting a screw, but I have yet to receive any mags, so I am ignorant of converting these to 15 rounders.  I understand that simple spacers do the trick, but I am not sure what is best for using as such and how to break down the mag for this alteration.

I use two different techniques depending on how lazy I am...the easy one is using a bic pen body and sticking it on the follower and trimming as needed to proper length...
second is a piece of wood...I usually use a trimming piece...the one i have is about 12 feet long and it fits inside the spring, cut it as needed and contour the corners so they dont hang up on the spring(round them off)
and voila NJ legal. 15 rounds
it works for thermolds, orlites and USGI.

I usually have some plastic "Wiremold" (surface-mounted electrical conduit) laying around. It's about 5/8 thick, cuts easily, and juuuuuuust fits inside the recoil spring. Very stable, weatherproof, solvent proof.

Quoted: I usually have some plastic "Wiremold" (surface-mounted electrical conduit) laying around. It's about 5/8 thick, cuts easily, and juuuuuuust fits inside the recoil spring. Very stable, weatherproof, solvent proof.

I knew there ws a use for all the scrap pieces I have lying around.  The wife had been hounding me to toss them out.

This will give an idea of what to do:

P.S this is in compliance (spell?) with the NJ State Police and local police deptos.

Using a secrew to stop the magazine follower at certain point:







Using a different screw system: (this one comes from the magazine floor)



and the most traditional and common: a piece of wood:

that screw throug the floor plate is an excellent idea.  I wish i would have used that instead of wood blocks when i sold mags to you jersey guys

It pains my eyes to see such mutilated mags...

Quoted: It pains my eyes to see such mutilated mags...

Agreed

I blocked all my mags so they don't even hold 10 rounds, I put them all away and take only factory Bushy 10 rounders to the range.
If I go out of state to shoot I take the 20's & 30's with me and I unblock them there.
For the range the extra 5 rounds isn't important if you have enough ten rounders.
And who ever that was that defiled those mags ,you're nuts, LOL

In January of 2002, the NJ State Police had proposed new Administrative Code Regulations which would have made temporary blocking of the mags illegal. They wanted the mags to be permanently altered. In June of 2002, the new rules change was put on hold for a period that I am not informed.

I have devised an alternate way of blocking the mags to 15 rounds. As opposed to the screw in the rear of the mag, which has the potential of interfering with the spring, aluminum rivots are placed in the mag bodies frontal area. The follower is the only contacting part of the mag which restricts the capacity.

See the following photos:

http://mywpages.comcast.net/kovba/temp/AR_Mag_1.JPG

http://mywpages.comcast.net/kovba/temp/AR_Mag_2.JPG

http://mywpages.comcast.net/kovba/temp/AR_Mag_3.JPG

POI: I used a #11 drill with a 3/16" aluminum rivot.

Why not just get some 5 round Colt blocked twenty round mags and alter them to fifteen rounds. The pop rivet is in the floor plate so you don't have to drill a hole in the mag or make any other mods to it.