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Discussion Starter · #1 ·
I saw some of your advice on my thread in the Five seveN section about NOT modifying a 20 rd 57 mag into a 15 rd mag; however,

I do not see the problem in converting a 10 rd PS90 mag into a 15 rd mag as I am starting with a mag that is legal in NJ.

What advice would you guys have in permanently converting it to hold 5 more rounds? Would cutting the spring inside work, or filing the black

plastic at the end of the spring? Any ideas? Has anyone extended a 30 rd into a 50 rd that might offer some advice to help me? I am sure there

are a few people in states like NJ where 15 is the legal maximum that have converted their 10 rd mags right? :oops:
 

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I doubt that you would have to cut the spring. NJ is a tricky state and I would be darn sure that I was on solid legal grounds before I modified anything. I am not familiar with the 10 round magazines for the PS90 as I only use 50's. Someone will chime in soon.
 

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the 10 round magazine has a 6 1/4 inch plastic plug in it. you can easily cut down the plug. i added an additional wood plug to my 10 round mag. to limit it to 5 so it would be leagal for me to hunt with it in NY. it functions fine. i am fairly confident that if you shortened the plug in the 10rd mag. it would function as well. us factory FN mags.

eddie
 

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I believe NJ is like Mass. in where only the 10 rd PS90 mag is legal. In states where you can own 30rd and 50rd mags it is easy to convert the 10 rd or 30 rd to make it 50rd.
you can buy a conversion plate here MPF Technology LLC
or you can just cut the spacer between the follower and the floorplate.
 

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No need to cut spring. FN uses the same spring for 10, 30, and 50 round mags.
 
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Discussion Starter · #6 ·
the 10 round magazine has a 6 1/4 inch plastic plug in it. you can easily cut down the plug. i added an additional wood plug to my 10 round mag. to limit it to 5 so it would be leagal for me to hunt with it in NY. it functions fine. i am fairly confident that if you shortened the plug in the 10rd mag. it would function as well. us factory FN mags.

eddie
I think the plastic plug is on a slant, it is not level (horizontal). I will try to take a picture of it when I get home and post it so I can get advice on where/how to cut it.
A wooden plug is good enough in NY to block/limit rounds? Is the NY gun law section of magazine capacity a bit more forgiving?


I believe NJ is like Mass. in where only the 10 rd PS90 mag is legal. In states where you can own 30rd and 50rd mags it is easy to convert the 10 rd or 30 rd to make it 50rd.
you can buy a conversion plate here MPF Technology LLC
or you can just cut the spacer between the follower and the floorplate.
I don't think I could even buy that because I am in NJ. Were you able to order it in MA?
 

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Discussion Starter · #7 ·
the 10 round magazine has a 6 1/4 inch plastic plug in it. you can easily cut down the plug. i added an additional wood plug to my 10 round mag. to limit it to 5 so it would be leagal for me to hunt with it in NY. it functions fine. i am fairly confident that if you shortened the plug in the 10rd mag. it would function as well. us factory FN mags.

eddie
Ok, I took a few pictures:

http://i34.photobucket.com/albums/d123/Sharrpe95/2012-01-07_00-33-58_405.jpg

http://i34.photobucket.com/albums/d123/Sharrpe95/2012-01-07_00-33-45_395.jpg

Where do you recommend cutting? It seems like if I cut it on either side I have to re-epoxy the ends back in place.
 

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You can post photos directly from your pc now. Just look click on the lil picture frame in the new post menu.
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Now what I would do is kindly request someone who can load a mag up to 15 rounds and ask them to post some really nice pictures. The best quality possible. Then compare the difference to your 10 rounder and make two cuts. One removing the base of the mag and the second cut the estimated distance required to load 15 seen in the picture provided by someone else. After that is complete do some sanding and prep work for the super glue or epoxy for getting it back in one piece.

Sorry I'm not much help otherwise. I do not own a PS90.
 

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I know I'm bringing up an old thread but before I go cutting up my 10 rd blocks, is there a better choice to get 15 rd magazines?

I took some measurements and I was going to go with VD's suggestion of cutting out a section in the middle of the 10rd block. I need to cut 7/8" out but I'm not confident of epoxy on this polymer so I was thinking about using a strip of metal (9/16" x 3" in the larger channel) and drill holes to allow small nut and bolts to hold everything together.
 

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I would remove the plastic mag block, load up the mag with 15 rounds, and put the block back in, see how far it sticks out, and mark it for cutting. Pay attention to how the mag spring looks when loaded to ten rounds, and match how the spring looks when loaded to 15.
 

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OK. I clamped the block on a vise and used a sawzall to cut one of my blocks 7/8" and I was able to get 16 rounds in so I cut my other blocks to 3/4" and sanded flat so maybe 13/16". I cut one of the spring plates with 1/8" extra instead of flat to the plate and used that on the first block so they all take no more than 15 rounds now with just enough play to load on a closed bolt, maybe 2mm but not nearly enough to allow another round. I didn't glue the spring plate to the block since they're held by the spring tension and not a moving part. The way the block is and the spring plate attached to the spring, there is no way for the spring plate to twist and move out of place.

One question - Do I need to epoxy the floor plate to the magazine body? I'm thinking I do since my 20 rd Pmags with 5 rd blocks for my AR are epoxied.

I need to move to a free state :-/
 

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One question - Do I need to epoxy the floor plate to the magazine body? I'm thinking I do since my 20 rd Pmags with 5 rd blocks for my AR are epoxied

Nope.
 

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I believe NJ is like Mass. in where only the 10 rd PS90 mag is legal. In states where you can own 30rd and 50rd mags it is easy to convert the 10 rd or 30 rd to make it 50rd.
you can buy a conversion plate here MPF Technology LLC
or you can just cut the spacer between the follower and the floorplate.

MPF link is having note - we are not going to ship to the restricted capacity states. :(
Anyone actually succeded with 10 to 15 rounds conversion? Could you post your tips/shots. Thanks!
 

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I believe NJ is like Mass. in where only the 10 rd PS90 mag is legal. In states where you can own 30rd and 50rd mags it is easy to convert the 10 rd or 30 rd to make it 50rd.
you can buy a conversion plate here MPF Technology LLC
or you can just cut the spacer between the follower and the floorplate.

Best solution, no need to drill, glue or saw/cut anything. I converted 4 mags in 10 min and could convert them back any time I need, thank you very much!
 

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New to this but I live in NJ and it seemed like common sense I simply cut 1 inch off the plastic, cut the end plate that connects to the spring, sanded the ends down, no glue I relied on the spring tension. All of this done in 20 minutes with a leatherman multitool and a little sweat. Ended up with 15 rounds and a little wiggle room. If it's still tight you can always sand down. Also it seems easy to revert by simply adding a piece of wood I between the two pieces
 
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