LorenzoS 100 Posted May 3, 2011 Could anyone explain or point me to some instructions for how to permanently modify a magazine to reduce it's capacity? I'm fortunate to have a supply of factory 15-rounders for my 9mm M&P. But I would really like to understand the process for future purchases. Thanks in advance. Quote Share this post Link to post Share on other sites
Dan 177 Posted May 3, 2011 IMO this has can-of-worms potential. I would stick with either factory 15 round or less, or purchase permanently modified mags from a reputable dealer. Otherwise, any work you do to permanently alter a magazine would have to be done out of state for legality purpose. Methods could include fused rollpins, rivets, and the such. It is good to know that NJ Statutes do not define a "high capacity magazine" other than one that holds more than 15 rounds. The NJAC code does have some further guidelines around them needing to be "permanently altered", yet stops at defining what exactly constitutes "permanently". It only gives some examples of what "temporary" means. “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." Quote Share this post Link to post Share on other sites
hd2000fxdl 422 Posted May 3, 2011 Not sure if my memory is going (probably) but wasn't there a post this past week that there were definitions on rifle Mag's in regards to what was considered permanent, however there was some gray area when if came to pistol Mag's as to what was required and/or defined as permanent. Yes I know the laws and am not condoning anything here just bringing this up for clarification as to what is really required. Harry Quote Share this post Link to post Share on other sites
Jon 264 Posted May 3, 2011 The following post is not legal advice, and could possibly land you in jail, but would be the way I would modify a magazine out of state to comply with NJ's 15 round limit... Remove the magazine baseplate, and stick a round or oval dowel under the follower cut to only allow 15rds into the mag. Then, weld or epoxy(if the magazines are plastic) the baseplate to the magazine. You will be unable to clean the magazine, but how often do they have to be cleaned anyway? Quote Share this post Link to post Share on other sites
LorenzoS 100 Posted May 4, 2011 Jon, thanks for the info. I do clean my magazines, especially after shooting outdoors where it picks up dirt and sand. A permanently sealed method will not work for me. I'm thinking that permanently epoxying the dowels to 2 diagonally opposite inside corners of the mag tube would prevent the follower from traveling to the bottom of the tube, while allowing me to clean the inside of the tube. Although I'm not sure I would be able to remove / insert the spring. Anyone else find a way to do this AND be able to remove the spring and follower for maintenance? Godammit New Jersey, godammit. Quote Share this post Link to post Share on other sites
Pew Pew Plates 358 Posted May 4, 2011 The spring wont be able to compress with those. Plus since you can remove the follower, you can reverse the dowels. The only way is really to weld/epoxy (even epoxy I am weary of) the baseplate Quote Share this post Link to post Share on other sites
Rifleman1 32 Posted May 4, 2011 I just went out and bought 15 round compatible magazines. 39498 - Smith and Wesson part number for the 15 round M&P magazines. I got them for $27 here: http://www.gandrtact...ction&key=39498 Quote Share this post Link to post Share on other sites
LorenzoS 100 Posted May 4, 2011 I do have the M&P magazines, thank goodness for Smith and Wesson's mercy on us NJ souls. I am asking as a general question in case I want to purchase something else where a factory mag is not an option. Quote Share this post Link to post Share on other sites
Jon 264 Posted May 4, 2011 Anyone else find a way to do this AND be able to remove the spring and follower for maintenance? No. If you were to attach something to the follower, you could simply replace the follower, which would not be a permanent modification. Quote Share this post Link to post Share on other sites
LorenzoS 100 Posted May 5, 2011 Thanks everyone. I was already a little reluctant to mess around with a modified magazine due to the legal ambiguities. Looks like the practical impact also makes it a no-go for me. Once again, goddamit New Jersey. Quote Share this post Link to post Share on other sites
DTtuner 21 Posted February 29, 2012 How about making a block, which sits in between the baseplate/follower and the internal spring. This block would compress the spring enough to only allow 15 rounds in the mag. Then, drill a small hole through the magazine, through the block, and out the other side of the mag. (front to back, in relation to rifle) One hole on top of block , and another through the bottom (close to the baseplate). Finally, purchase some long rivets, and drive a rivet through each hole. NOTE: the block can be made of any material (plastic, metal wood) and can have space on each side to allow some level of cleaning to be performed. Nobody can say that a rivet is not permanent. Quote Share this post Link to post Share on other sites
Babaganoosh 192 Posted February 29, 2012 With the right tools nothing is permanent. Quote Share this post Link to post Share on other sites
RedBowTies88 41 Posted February 29, 2012 With the right tools nothing is permanent. Exactly, For my saiga I removed my baseplate and permidently attached a post the pertrudes upward within the spring and stops the follower when it reaches 15 rounds. IANAL and this is in no way legal advise pretaining to pinning a mag Quote Share this post Link to post Share on other sites
RedBowTies88 41 Posted February 29, 2012 in NJ what constitutes a magazine? if you seperate it into 4 pieces and store them seperatly is it still a magazine? Quote Share this post Link to post Share on other sites
DTtuner 21 Posted February 29, 2012 With the right tools nothing is permanent. "With the right tools" I can saw my rifle's barrel down to 5 inches.... Is it suddenly an SBR? No. I'm 110% all about abiding by the law. But this is just paranoia now. Quote Share this post Link to post Share on other sites
Babaganoosh 192 Posted February 29, 2012 I'm not paranoid, I'm just stating that the term "permenent" is ridiculous when it comes to magazines Quote Share this post Link to post Share on other sites
exfed2002 4 Posted May 31, 2015 Could anyone explain or point me to some instructions for how to permanently modify a magazine to reduce it's capacity? I'm fortunate to have a supply of factory 15-rounders for my 9mm M&P. But I would really like to understand the process for future purchases. Thanks in advance. I know this thread is long dead, but................................ SIG has produced some shortened tube, lengthed baseplate models for the P series, and I have several ten rounders for my 40 229. What they are doing now is putting deep dimples in the sides of compact length mags that will not allow the follower to go deeper than to allow ten rounds when the magazine is loaded. When there are no rounds in the magazine, the follower and spring can pass without binding for disassembly and cleaning, but the rounds sit outside the follower when loaded and connot pass the dimples. MecGar is doing the same thing with ten round mags for the HiPower 40, except their "dimples" are longer and go all the way to the base of the tube. In neither of these cases could one really reverse the modifications without destroying or distorting the tube to the point that it would be useless as reversing the dimples is not as easy as putting them in. I have modified some 12 round 250/320 subcompact mags to ten rounds by putting supporting wood blocks inside the tube to prevent collapse. I then take a punch and dimple the mag tube at the points where the cases would engage the dimples when loaded to just beyond ten rounds. It is important to support the sides of the tube while doing this. It would be very difficult to remove the dimples without destroying the magazine or distorting it to the point where it would be useless. I have had no reliability issues with these mags. Quote Share this post Link to post Share on other sites
son of sam 9 Posted June 8, 2015 The mags I have seen have a nylon block pop riveted onto the bottom plate. The person I know who does this actually makes them all 14rnd. Reason being, if made to 15rnd with such a long spring it may be possible to wiggle another round into the mag. At 14 rnds there is no chance of compressing and wiggling 2 rnds past the spring. This infor is from a very reputable LGS. I in no way endorse or recommend the practice of bringing high-cap magazines into NJ, offered only as an example. I have also seen mags pinned from the side then a little tack weld on the spring, however they dont function as well from my experience. Personally I buy all 10rnd mags for my 1911/9mm, AR, 22/45, B96 etc... I like to have the same round count throughout all my common guns. When shooting steel or other comp it makes it easier to count out. Quote Share this post Link to post Share on other sites
Newtonian 453 Posted June 8, 2015 Save yourself a ton of grief and possibly money: Buy 15 round mags from the manufacturer or a reputable after market company. Gun smiths don't work for free. And if you have them pinned or do it yourself and have failures you'll kick yourself. Not to mention the legal stuff. Quote Share this post Link to post Share on other sites
mcm308 0 Posted July 7, 2015 Just some thoughts on the subject... If the magazine is permanently assembled with the base plates pinned and epoxied to the point they cant be opened back up without power tools and destruction, who gives a hoot how the inside is actually blocked. The mag assembly is the permanent modification. Quote Share this post Link to post Share on other sites
mcm308 0 Posted July 7, 2015 One more thing...i never saw anything in writing where it says that one cannot accept parts to build 15 rounders... Play at your own risk.. Quote Share this post Link to post Share on other sites
Alex V 99 Posted July 14, 2015 So I got a stupid question; if the ability to remove a modified base plate and replacing with a non modified constitutes an illegal magazine, how are the 15-round M&P mags legal? They base plate is not permanently attached and the only difference is the spring. A person could replace that spring with one from a 17 round M&P mag and have 17 rounds in there. The 15 rounder spring has a number of collapsed coils at the bottom but the height of the spring is the same, the mag body is the same. So whats the difference between a factory 15 round M&P9 mag and a modified baseplate mag? Does the fact that the metal body only has holes numbered up to "15" rather than "17" I just don't follow... Quote Share this post Link to post Share on other sites
mcm308 0 Posted July 14, 2015 So I got a stupid question; if the ability to remove a modified base plate and replacing with a non modified constitutes an illegal magazine, how are the 15-round M&P mags legal? They base plate is not permanently attached and the only difference is the spring. A person could replace that spring with one from a 17 round M&P mag and have 17 rounds in there. The 15 rounder spring has a number of collapsed coils at the bottom but the height of the spring is the same, the mag body is the same. So whats the difference between a factory 15 round M&P9 mag and a modified baseplate mag? Does the fact that the metal body only has holes numbered up to "15" rather than "17" I just don't follow... I dont either... Its a shady grey area. I suppose because that MP mag is sold and marked 15 rounds, it is legal. I would assume you are not suppose to know the mag will hold 17 changing the spring out....if thats the case Quote Share this post Link to post Share on other sites
TulsaJohn 1 Posted July 14, 2015 I could take a large ammo can drill a 1/4" hole at the top, fill it with 1200 rounds of .22 add a spring, with some lube, and centrifugal force. duck tape to the bottom of my gun, and shoot it upside down. it wouldn't be very reliable. Quote Share this post Link to post Share on other sites
PK90 3,571 Posted July 14, 2015 You can put 16 rounds into a Glock 19 magazine. Does that make it illegal? Quote Share this post Link to post Share on other sites
Alex V 99 Posted July 14, 2015 You can put 16 rounds into a Glock 19 magazine. Does that make it illegal? I have heard that before, but none of my G19 mags will take a 16th round. I can barely get the 15th in there. Maybe I am just a wimp. Like I said, the answered seemed to definitive regarding a modified base plate being illegal if removed, but changing a spring is gray area? I hate this state. Quote Share this post Link to post Share on other sites
TulsaJohn 1 Posted July 14, 2015 You can put 16 rounds into a Glock 19 magazine. Does that make it illegal? Same with a 9mm sig P226 Quote Share this post Link to post Share on other sites
bhunted 887 Posted July 14, 2015 Same with a 9mm sig P226 That's interesting. I have my p226 right here and there is no room for a 16th round. Maybe if I get my mallet and whack it harder. Sent from my iPad using Tapatalk Quote Share this post Link to post Share on other sites
Blacksmythe 71 Posted July 15, 2015 If It says 15 rounds it must be so.. and because of my poor inner city education I cant count sooooo........... Quote Share this post Link to post Share on other sites