Uzi mag conversion

[SIGPRO 226]

I'm putting together a dedicated 9mm ar and wanted to see if anyone here has converted there uzi mags themselves. I do have access to a endmill. I really dont want to nuter the mags with a dremel etc. Any input/tips would be appreciated thanks.

 

[Rob Boudrie]

I know Greg at GFA in Natick has plenty of experience doing this.

Which conversion unit did you get for the AR? I just got a RRA 9mm conversion unit and it looks pretty good, though I have to wait for my Form 1 before I can put the 9mm upper being stored at a dealer on it.

 

[SIGPRO 226]

I know Greg at GFA in Natick has plenty of experience doing this.

Which conversion unit did you get for the AR? I just got a RRA 9mm conversion unit and it looks pretty good, though I have to wait for my Form 1 before I can put the 9mm upper being stored at a dealer on it.

I have a dedicated GPI colt mag lower.

 

[RDG]

I did the dremel thing,,, they turned out fine.

Heres the the measurements you'll need

 

[SIGPRO 226]

I did the dremel thing,,, they turned out fine.

Heres the the measurements you'll need

View attachment 173515

View attachment 173516

I found the same specs also thanks.

 

[G&N Gunsmithing at Gartman Arms.]

Don't us a dremel on your firearms, it is not an accurate cutting tool. You can do this "conversion in about 2 minutes in an upright milling machine with a 1/4" end mill. Uzi mags have pretty hard steel, and they like to chatter alot in the mill. Just use a little oil and the cut goes pretty smooth. I did a dozen of these for a customer in under 45 minutes last month in my Bridgeport, there is no reason to over complicate it with an abrasive cutting wheel.

 

[SIGPRO 226]

Don't us a dremel on your firearms, it is not an accurate cutting tool. You can do this "conversion in about 2 minutes in an upright milling machine with a 1/4" end mill. Uzi mags have pretty hard steel, and they like to chatter alot in the mill. Just use a little oil and the cut goes pretty smooth. I did a dozen of these for a customer in under 45 minutes last month in my Bridgeport, there is no reason to over complicate it with an abrasive cutting wheel.

Ok im on the same page with not using the dremel would you go off the specs above ? Thanks.

 

[Brian5582]

I used a dremel also. I just cut the slots small and adjusted as needed till they worked. A few thousand rounds later I don't think I have has a single hiccup with my converted mags... The factory 10 rounders are a different story.

gun is a ASA side charger

 

[CrackPot]

The cutting gets it functional. You need to spot weld a piece of spring steal to the follower if you want it to lock open when empty

 

[Steelitall]

The cutting gets it functional. You need to spot weld a piece of spring steal to the follower if you want it to lock open when empty

...Which would render them non functional in their original gun, thus invalidating them as preban magazines in Mass

 

[eisenhow]

...Which would render them non functional in their original gun, thus invalidating them as preban magazines in Mass

Do you have citation for the case law on that?

 

[bill o]

Do you have citation for the case law on that?

I'm gonna cite wild speculation or possibly a gun shop clerk.

 

[Rob Boudrie]

...Which would render them non functional in their original gun, thus invalidating them as preban magazines in Mass

Can you cite a law, CMR, or case law on this or are you just guessing?

 

[soam]

Back during the federal AWB the ATF provided a ruling on modifying preban mags to work in different guns.

http://www.titleii.com/bardwell/atf_letter88.txt

Basically if it still worked in the original gun, then the mag was still considered preban. If it didn't, then it was considered a new mag.

Whether any of this applies to MA is anyone's guess, but it's not like people are just making it up.

 

[Rob Boudrie]

Back during the federal AWB the ATF provided a ruling on modifying preban mags to work in different guns.

http://www.titleii.com/bardwell/atf_letter88.txt

Basically if it still worked in the original gun, then the mag was still considered preban. If it didn't, then it was considered a new mag.

Whether any of this applies to MA is anyone's guess, but it's not like people are just making it up.

They are making it up with respect to MA law. The only accurate answer is "nobody knows for sure".

 

[Steelitall]

pulling from what ive read here mostly
the atf letter in this thread, for instance
https://www.northeastshooters.com/vbulletin/threads/43950-Modifying-preban-mags-legality/page2

"If the altered magazine could no longer function in the firearm for
which it was originally designed, it is our opinion that a new
magazine has been manufactured."