9mm AR mag blocks

[USAF_Vet]

Is it just me, or is it cheaper and easier to simply buy a dedicated lower for a 9mm AR rather than buy and install mag block?

I'm finding 9mm lowers, complete, for under $200 (whether or not they're in stock is not the point). On the other hand, the quality 9mm mag blocks are also in the $150-$200 rice range, and you still need a complete lower to run them.

I want to build an AR-9 that utilizes cheap and plentiful Uzi mags (or S&W 59 series mags to go with two of my other 9mm pistols). Looks like most Uzi mags need to be modified so they can work with Colt pattern AR-9 blocks, and I don't think anyone makes a mag block for S&W 59 series mags.

I'm honestly thinking of fabricating a mag block to run unmodified Uzi mags. I've got an Uzi mag well fold and weld kit from the Flat Spot already built and looking for a project for it. Looks like all I need to do is fabricate a front spacer with feed ramp and rear spacer with ejector and weld it into my steel flat AR lower (also from the Flat Spot).

I'm not really asking a question, just sort of ranting. Seems prices would be more competitive on the drop in blocks for standard AR lowers. Since 9mm seems to be the plinking round of choice for many these days, I was hoping to see mag blocks a bit more reasonably priced.

 

[HJ857]

My first AR9 I did go with a magwell adapter. The first one was I think a Pro Mag cheapy. It didn't work for me. At all. But others seem to be able to get it to run.

After that I went with the Spike's Enhanced which was stupid expensive but works decent and is a breeze to install. Mine is very finicky with magazines.

Eventually I wanted my AR15 back and built a dedicated 9mm lower.

After all this my conclusion is that it's far better to go with a dedicated lower.

I'm running a CMMG lower and the AR Stoner mags run perfectly in it (Colt pattern). 19 bucks at Midway and that ain't too bad.

 

[dogmush]

I have one with a Spikes mag block that works great.

That said where the mag blocks shine is if you are going to sbr the lower. Then you have the full range of AR calibers available in your sbr with not much work.

 

[BSA1]

USAF_Vet,

I'll see your rant and raise you one.

My rant is why aren't there low cost good quality lowers like those available for AR magazines? It can't be difficult to cut a smaller hole in the magwell.

 

[CLP]

This CMMG dedicated 9mm lower is excellent in fit, finish, and function.

 

[barnbwt]

The price will fall once demand warrants an increase in supply & manufacturers overshoot production...

I swear, it's like people don't even remember 100$ AR lowers from like a year ago . Be happy there actually are makers of 9mm AR stuff now, since it was basically nonexistent except for Colt stuff until recently.

TCB

 

[USAF_Vet]

USAF_Vet,

I'll see your rant and raise you one.

My rant is why aren't there low cost good quality lowers like those available for AR magazines? It can't be difficult to cut a smaller hole in the magwell.

I thought that was sorta implied in my OP. We have dedicated lowers available, but as CLP linked, they are about $200 for what is essentially a stripped lower.


I'm hoping, eventually, 9mm AR lowers will drop in price to be closer in price to standard AR 5.56 lowers.

In the meantime, I'm looking forward to my sheet metal 9mm AR project, although I think I'll need a 9mm upper before I do the final fit and fab of the ejector and feed ramp.

HJ857, I did see the Promag adapter, and for under $50 (when other are $150-$200) along with Promags less than stellar reputation, I chose to avoid it at all costs.

Dogmush, I have an AR lower that I plan to SRB next year. Currently it is my AR pistol with a 10.5" .223 Wylde 1:8 twist heavy barrel. SBR'ing that receiver is the main reason I want a drop in 9mm conversion block, rather than a conventional purpose built 9mm lower. I'd be happy with either, or both, but think a 9mm SBR would be a better use for the caliber. 16" of barrel is a bit unnecessary IMHO,and would prefer something in the 7-10" range, especially if I ever get a suppressor and shoot subsonics.

barnbwt, I know 9mm AR stuff is still fairly young, aside from the Colts, which were practically unheard of. I had no idea they had the history they do.

I assume that prices for AR9 stuff may eventually drop. Another thread on AR9s the OP got a complete AR9 upper for $320. When I first looked into AR9's some time ago, a bolt and barrel would cost much more than that, with no upper receiver or upper parts kit.

If I decide to fabricate my Mag Block, I'll do a build thread with bunches of pics.

 

[Quiet]

New Frontier Armory is making a dedicated AR9 receiver that uses Glock magazines.

$169.99 for stripped receiver
$289.99 for complete receiver with B5 Bravo stock

 

[maxxhavoc]

HJ857, I did see the Promag adapter, and for under $50 (when other are $150-$200) along with Promags less than stellar reputation, I chose to avoid it at all costs.

I use the ProMag magwell adapter. Mine works flawlessly with Metalform magazines, and may misfeed once in 3 magazines with the cheaper ASC magazines ($14 each for 32rnd mag.)

I figured if the plastic held up (it does) then there would be nothing that couldn't be sanded, filed, melted, or shimmed to make it work. All it does is align a magazine after all.

Luckily, mine dropped in and worked fine from day one, including Bolt Hold Open. I only have about 1500 rounds through it, but it shows no signs of wear.

 

[langss]

This is what I'm using in mine.
RRA-9MM0115 RRA 9mm Magwell Conversion Block

Obviously because I live in California I have other limitations, but I'm at 7500 rds without a problem related to the Magblock.

 

[BSA1]

USAF_Vet,

Don't get me wrong. I agree with your rant. I would prefer a lower that uses Beretta 92 mags but that is really dreaming. So a decided AR Lower that uses Glock mags will be a compromise I can live with.

Even with the CMMG Lower at $200.00 that still puts a build cheaper than the Beretta CX Storm.

 

[wally]

All it does is align a magazine after all.

It also holds the ejector. That is where my Pro-Mag failed -- lots of stovepipes until I forced epoxy putty into the gaps to make it "rigid". I got mine for cheap at a gun show it worked pretty well until I got my Hahn which was back ordered at the time.

There are two types of blocks, top loading and bottom loading. Hahn makes both kind the Pro-Mag is top loading.

The top loading requires you remove the BHO lever to install or remove, the bottom loading lock in with a setscrew. You have a bit of adjustment with the bottom loading and their set screw, the top ones you never have to worry about the mag coming out with the block. I have both kinds and see no practical difference, if you don't want to change calibers on the lower the top loader will be great.

The Glock mag lowers are great, but either they dispense with the BHO or its a finicky adjustment to make reasonably reliable. Your choice of bolt carriers is also reduced unless you can mill a "standard" RRA/Colt style bolt to fit the Glock mag feed lip opening (not hard, I did it).


Another issue is ramped carrier to use a standard hammer or un-ramped that needs a "9mm hammer". The ramped carrier jams up on the 9mm hammer, the unramped carrier has a bad trigger slap with a standard hammer (enough that some folks report the axis pin holes "egging out" eventually.

 

[Arizona_Mike]

If it were not for wanting to only SBR one lower, a dedicated lower would probably be the best idea. Mag blocks, bolts, and mags can be very picky in brands and versions to get reliable feeding.

Mike

 

[Caliper_Mi]

It also holds the ejector.

And the BHO transfer lever or whatever you call it so the last shot hold open works. I got a PSA mag block with their 9mm kit. Works great and gives me LSHO when using Colt style mags with the little hold open tab.

 

[HJ857]

...and the feed ramp, and established the correct angle and height of the ramp.

 

[USAF_Vet]

Can anyone take a few measurements for me? I've decided to go ahead and try to fabricate a mag block.

A CAD diagram would be ideal, but in lieu of that, The angle and length of the feed ramp would be wonderful, as well as the position and height of the ejector.