Converting a M16

[Tackdriver VillenTactical]

I want to convert a 5.56 M16 to 9mm. What are my considerations as far as the lower receiver is concerned? I assume the LPK is the same and that I need to put in block of some type. Am I on the right track or are there other things to consider?

Dave

 

[14paul]

Magazine, drop in mag adapter, 9mm upper, & 9mm bolt/carrier assembly.

 

[icyclefar]

Depending on the make of 9mm bolt that you purchase, you may need a special 9mm hammer.

If you want to avoid that, make certain to purchase a ramped 9mm bolt.

Some magazine blocks need to be pinned in, others are top loading and do not require any modifications.

Last I looked there were magazine blocks for either Uzi or Sten mags. If you go with Uzi mags you will nee to cut a new mag catch into them, not sure about the Sten set ups.

 

[soam]

Ensure that the 9mm BCG you get is ramped so it works with the standard hammer. I believe most new units nowadays are made this way, but in the past the 9mm BCGs were made in such a way that required a special hammer to use.

 

[Rob Boudrie]

The first choice you have to make is what kind of magazine - Colt/Uzi or Glock. JP makes a nice lower for Glock mags. For those of you that want to convert in-MA lowers, or prefer to use low cost and readily available UZI mags, the Rock River conversion block is excellent. The RR block is bottom loading, but locks in place by turning a allen bolt that pushes grippers out to the side. This works wonderfully, and does not scratch or mark your lower, and no modifications are required.

Also, you will need a recoil spring/buffer designed for 9mm. I use the JP captive unit (remove the part that holds this in place when the lower is removed if you go with this model, otherwise disassembly is a real pain)

As to UZI mags - you have to cut a new mag release notch, and lower the opening at the back of the magazine - then they work perfectly. The only catch is that you do not have bold hold open. If that causes you problems with only 32 rounds, get the Taylor Freelance UZI mag extension for 42 rounds. Cheap pre-ban Uzi mags are available on line, or in stock at GFA Armsteck, Natick. I had my Uzi mags modified on a $300K milling machine, however, the local USPSA Grandmaster at Hopkinton did his on a dremel and those work perfectly, just not as pretty.

 

[LuvDog]

Get a heavy buffer for 9mm

 

[01SVTvert]

If it's actually a Registered M16 then get KNS pins. 9mm can egg the pin holes.

 

[steve8140]

Here’s some pictures of the ones I cut with a dremel. Took about 10 minutes each and function tested at the range.

I went with the uzi mags because of a few reasons.
1) 32 round preban mags can be easily found. I paid less than $5 each a few years ago. I bought 50 of them. They showed up still covered in Cosmoline.
2) in my opinion these will not wear nearly as fast as Glock mags will being all metal.
3) have you looked at the price of preban Glock mags? Unless your fine using 10 rounders it’s not worth the price people ask.

 

[Cur]

The first choice you have to make is what kind of magazine - Colt/Uzi or Glock. JP makes a nice lower for Glock mags. For those of you that want to convert in-MA lowers, or prefer to use low cost and readily available UZI mags, the Rock River conversion block is excellent. The RR block is bottom loading, but locks in place by turning a allen bolt that pushes grippers out to the side. This works wonderfully, and does not scratch or mark your lower, and no modifications are required.

Also, you will need a recoil spring/buffer designed for 9mm. I use the JP captive unit (remove the part that holds this in place when the lower is removed if you go with this model, otherwise disassembly is a real pain)

As to UZI mags - you have to cut a new mag release notch, and lower the opening at the back of the magazine - then they work perfectly. The only catch is that you do not have bold hold open. If that causes you problems with only 32 rounds, get the Taylor Freelance UZI mag extension for 42 rounds. Cheap pre-ban Uzi mags are available on line, or in stock at GFA Armsteck, Natick. I had my Uzi mags modified on a $300K milling machine, however, the local USPSA Grandmaster at Hopkinton did his on a dremel and those work perfectly, just not as pretty.

I followed Rob's advice and got a JP Rifles upper, BCG, and captured spring assy, the RR block, and modified Uzi mags for my 9mm AR and it's a damned pleasure to shoot.

I will caveat, that I'm "fairly" mechanical, and with a dremel and vise, 2 of the 4 Uzi mags I have don't 100% function. As noted GFA can set you up with ones you won't have to muck around with, also CrackPot has a mill and some mags, too.

 

[groundscrapers]

Mean arms has a slick adapter that fits into a pmag and feeds 9mm with no magwell.

 

[amm5061]

Stern Defense offers a complete conversion kit that will work with 9mm Glock mags.

They also have magwell adapters for 9mm Beretta 92 mags, and ones for M&P .40 S&W and .45 ACP.

PRODUCTS