How does one REDUCE the capacity of a magazine?

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Jun 3, 2008
My brother still lives in New Jersey. He bought a M&P 9mm back when the two extra mags were being offered. What I did what had him send the two extra magazines (17 round capacity) to me since he can't have magazines with a capacity greater than 15 rounds.

This problem has reared its head again since I have a pistol with a 16 round capacity I'd like to bring up there to shoot.

Has anyone ever blocked a magazine like this? His can be more permanent but I'd like mine to be brought back to its full capacity when I leave that place.

Any ideas?
I believe you can no longer "block" magazines like that in NJ. People used to do that with AR-15 mags but I (again) believe I was reading somewhere that the mags now have to be pinned or be blocked by a follower (ie, longer follower).
THe only time I've ever heard of magazines being blocked legally was with shotgun tubular magazines for hunters.

Not saying your idea ain't legal. Just sayin I never heard of it being legal.
I'm sure there's a parts kit out there some where that will do it. or you could just buy the proper magazine and use it in NJ
Buy a couple of factory 10 round magazines for range use and keep the high capacity magazines at home. Unless you are involved in the drug trade or a murder, no one is going to search your house.
Buy a couple of factory 10 round magazines for range use and keep the high capacity magazines at home. Unless you are involved in the drug trade or a murder, no one is going to search your house.

Or a self defense shooting. Hide 'em good if you're gonna hide 'em.
For a while, temporarily-blocked magazines were legal in NJ. Then there was a period of time where the AG said they weren't legal anymore. Finally, in the last re-drafting of the firearms chapter of our Administrative Code, it's now in black and white that only permanently-blocked magazines are legal:

NJAC Title 13, Chapter 54, sub-chapter 1.2:

"Large capacity ammunition magazine" means a box, drum, tube or other container, which is capable of holding more than 15 rounds of ammunition to be fed continuously and directly therefrom into a semi-automatic firearm. A large capacity ammunition magazine that has been permanently altered so that it is not capable of holding more than 15 rounds of ammunition will cease to be defined as a "large capacity ammunition magazine." An ammunition magazine, which has been temporarily blocked or modified from holding more than 15 rounds, as by a piece of wood or a pin, is still considered to be a "large capacity ammunition magazine."
I'll give you my idea and tell me what you think.

I was going to tap threads into the bottom of the follower, then thread a nylon bolt into it, so that it would act as a block.

Good enough?

Does anyone know where I can get a follower for 16 round Witness mags with longer skirts or something?
The legal distinction appears to hinge on "permanent" or "temporary". In this application, it seems as if a bolt would be no more permanent than the pin which is specifically insufficient. A longer follower might work, but only if you could not disassemble the floorplate and replace it. Epoxy might help that issue, but then you can't break 'em down to clean 'em or replace springs.

Are there any grandfather provisions that allow hi-caps owned prior to the prohibition to be retained? If so, can those mags be distinguished from current production? If no grandfather provisions, there may have been an unlawful taking of private property.

Don't you wonder where the 15 round cutoff came from? M-1 carbine?
The original wondernines such as the Beretta 92 were generally 15+1, weren't they. Besides, it cut off the evil Glock.

I figured the longer skirts would be a permanent modification, since the skirt is now part of the magazine. Similar to removing a collapsible stock from an AR and putting on an A2 fixed stock. It is now considered part of the gun even though it can be changed back.
The original wondernines such as the Beretta 92 were generally 15+1, weren't they. Besides, it cut off the evil Glock.

I think most of these laws were "just in case laws" when it came to mag capacity. They wanted to make sure that retired LEOs wouldn't be affected or something to that nature (that's not a fact, I'm guessing, but it's probably something similar). 15 rounds could be a Beretta 92 or a Glock 19. NYC has a 17 round limit. I figured that had to do with a Glock 17 (though in a another thread someone told me they didn't issue those to NYPD). Anyway, I'm almost 99% sure those laws were to cover commonly owned pistols or pistols commonly used by LEOs.
Move out of New Jersey?

Sorry, just had to throw that out there. You have 49 other choices, of which about 46 are better from an RKBA perspective. And some might say 49...:neener:
New Jersey wants to see WELDING. Permanently welding something to the follower so it cannot hold more than 15 rounds, or plugging it and welding the magazine floorplate on.
Question. Without access to welding equipment, how would one permanently reduce the capacity of a marlin model 25 magazine to 5-rounds?

Some of the ways we permanently block magazines here are:

- Install a replacement one-piece block/floorplate in the magazine, drill and rivet it in place.
- Epoxy a block to the floorplate, and blind-pin the floorplate to the mag body
- Install a roll pin through the mag body, restricting the travel of the follower. Epoxy over said pin.
same as for hunting in mi probably...has to be permanent modification....load your allotted rounds into it then take a hammer and punch and give it a couple whacks on each side. we are only allowed a gun capacity of 5 rounds on semi-autos other than 22s for any hunting here.
Aside from the manifold issues of being a "furriner with a handgun" in NJ, you'll face another.......The NJAG ! The NJAG has, by fiat, changed all the rules regarding "alterations in magazine capacity" - at least for NJ gun owners ! Last I knew "temporary mods" (excepting plugs in tubular shotgun magazines), for purposes of reducing capacity to meet state mandates were deemed illegal ! >MW

So that's why some folks I know were prosecuted ! Seems the owners of old Stevens/Mossberg/Itheca et al .22RF rifles with with tube mags have become "dangerous felons" in the eyes of the NJAG ! Depending upon Long or Long Rifle anywhere from 17 to 22 rounds can be loaded into these long barreled/FL mag beauties !

BWTH, start stuffing 2.5" shells into several of my 2.75" shotguns and you'll get the same result ! >MW
You could fabricate a mandrel to stamp a groove horizontally on the magazine body, to limit how far the follower can go down. This is exactly how many dedicated 10-round mags were made during the AWB. This should meet the requirement of being permanent, since it could not readily be pounded back out. Of course, you would need to be a pretty skilled machinist, too.
Did no one notice the thread necrophilia, or did no one care?

In addition to that, I must say something on topic, so here it is:

Magazines typically costing from $15-$30 a piece, that is a pretty small price to pay, as compared to what it will cost if you find out your DIY magazine fix is not in compliance with the law. Too much at risk, IMO.
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