AR-15 upper to hold barrel in place, a barrel of choice, and bolt.

Mag block of choice to hold them smaller 9mm mags in the std AR-15 magwell, some mags, and ammo.... add suppressor if wanting to shoot suppressed.

I hope this question isn't redundant.  I've owned serveral ARs in .223 and never had one in anything else.  I'm probably going to get a "slide fire" stock and wanted to get an AR in 9mm so it would be cheaper to shoot.  I've never built my own AR, I've only customized smaller parts like stocks and forearms, etc.  I'm looking at the Olympic Arms k-9 which can be found for approx. $800.  Considering that this would be just a "plinker" to shoot, would any of you not recommend this gun?

I have a question for you people, I am totally new to the 9mm AR uppers.

I just bought a Oly Arms 9mm upper, the upper came without the bcg but that's taken care off as we speak.
Sins the upper I bought is an A2 and I want to make it a flattop the only thing I actually bought is a barrel
Now I did order a new flattop upper to put the barrel in, its a Aero Precision assembled 9mm upper from Karris guns.

I was thinking about buying the Promag mag adapter from Brownells so I will be able to use Uzi mag's in my Oly Arms AR.
Off course I know the Oly Arms normally uses the Sten Gun mag's.
The thing is, I can't find anything on the net about the possibility of using Uzi mag's in the Oly Arms upper.
On the Brownells website however they state that in order to use the Promag adapter in a Oly Arms system the only thing that needs to be done is remove the ejector from the Oly Arms upper???
Any off you can confirm that this will work at all??

I already did ask the gun tech's at Brownells but the answer I get from them does not help me at all.


The specs on the Brownells website say this:


Here a link: http://www.brownells.com/.aspx/pid=42515/Product/AR-15-M16-9mm-MAGAZINE-ADAPTER

What do you guys think, will this work or is it a waste off time to try and make it work and should I just buy the Sten mag adapter instead??

Unless it was specifically ordered as an unbarreled Olympic-pattern conversion upper, the Karri's Guns 9mm is a colt-pattern upper.  It will need to be drilled for the installation of an Oly-pattern spring wire ejector.  Colt- and Olympic-pattern bolts are also not the same, so hopefully you ordered the correct Olympic-pattern bolt for use with your Oly Arms 9mm barrel.





Oly magazines feed from the very front of the magwell, since the Oly feedramp is part of the barrel extension, not part of a magblock.

As brownell's noted, the ejector will need to be removed from the magblock so as not to interfere with the Olympic ejector in the upper.  That Brownell's has that tech note might be a helpful sign that they've actually tried it, and gotten it to work before, though I've never heard of such a combination.

Sten magazines and Oly factory magazines are single-feed mags, with very narrow maglips.  You'll need to test for fit to see if the bolt will clear the double-feed Uzi maglips.  You'll also need to verify that the Olympic bolt can clear the feedramp on the front of the magblock, and that the combination feeds reliably from uzi mags.

If all those things work out, then yes, it'll work - and please post pics and after-action reports if you attempt this and get it working.

If you're unsure about any of this, and really want to use Uzi mags and the Karri's Arms upper you've already bought, and the bolt you ordered isn't an Olympic-pattern bolt, then the path of least resistance would be to get rid of the Oly barrel and buy a colt-pattern 9mm barrel to finish out your build.

@ Circuits,

This is the bcg I ordered: Link
According to the Brownells gun tech the ejector should be removed from the Oly upper, not the mag block ??



When I take a look at the Oly Arms manual there is also a modified uzi mag in the pictures (Modified Uzi Magazine with built-in magazine well block), so I guess it's not impossible?
I will just have to wait until I get all my stuff in and then see what is possible and what not.

To be sure I can at least shoot the upper, I also did order the Sten magazine adapter: Link
The thing is, I already have a bunch off Uzi mag's and I would like to be able to use the standard mag release instead of the mag release on the Sten adapter.

Hopefully I did order the right stuff for my project (I assume there is only one type of Oly bcg?)

So, my questions now are:

Did I order the correct bcg?
Can I use the Aero Precision upper receiver (drilling the holes for the ejector wil be no problem)? Link
Will the bcg I ordered fit the Aero Precision upper receiver?

Hope you can give me some answers again.

Here some pictures off my upper:

That's an oly pattern BCG, good to go.  If the Uzi magwell block's ejector fits and works with the oly bolt, you could perhaps use that instead of the oly type wire ejector.  Make sure the mag block ejector fits and works before you decide to remove the oly ejector.



That means the bolt will clear the Uzi mag feed lips, then.  Just need to worry if it will clear the mag block feed ramp, though if it clears the lips, it will probably also clear the feed ramp.

Ok, thanks so far.
Just got a message from Oly Arms, I asked them if the Pro Mag adapter would work with my upper.

This is there answer:



So I guess there is very little chance this will work but still I am going to try to make it work.

Update on my Oly Arms 9mm project.

So far the bcg came in but it was the wrong one, a .45 instead off a 9 mm, it is being exchanged as we speak.
The Uzi mag conversion is a no-go, but I did fool around a little with a Sten mag.
I do not wish to work with a Sten mag block, to much risk off hitting the standard AR mag release and with that dropping the mag and the mag block all at ones.

So I was thinking of a way to adjust a standard Sten Mag and turn it in to a full contour straight AR magazine.
Because I did wish for a bolt hold open function I did some measuring, welding and dremeling to make that hapen.

Result is a full contour AR Sten magazine with a working bolt hold open function.
I did weld it together already so I can not show the interior off the bolt hold open solution I came up with, I will come back with these pictures later (if all works well I have to adjust 11 more Mag's).
Now I have to wait until the bcg arrives before I can do some testing on the shooting range.

If all works out the way I did plan then I will make a better version of the full contour straight Sten AR mag and I will apply some Birchwood Casey gun bleu to the welded part to make it look good.

Here some pic's off the prototype:

Do they still make the UZI mag magblocks? I thought someone here said they no longer did.

Who they?  RRA makes or sells one, so does Spikes and perhaps others such as VM Hitech.

Is it okay to use 9mm+p in CMMG 9mm barrels?

This is my 1st post and my 1st experience with a Colt 9mm. I’m sorry if I’m at the wrong place on this forum. I walked into my local gun shop. The owner handed me a rifle and said I just bought this 9mm at action. I looked it over good and told him it said 5.56 on the lower. He said, Is that not right? I told him, I thought it would say 9mm If It was a factory 9mm. I took pictures of the gun and started researching it a little, I very quickly learned that the factory Colt 9mm’s online had roll pins holding the block in the mag well. This Colt lower did not, it has a block in it with what appears to be an allen bolt going up from the bottom. At this point I was convinced that it was a 5.56 just made into a 9mm probably as cheaply as possible, but as I started checking out the upper some more the letters on the side of the carry handle and the A-3 above the ejection port matched up to markings I found on Colt uppers oline. I also found the barrel was marked C MP 9mm nato. The gun has a Colt factory mag and the collapsing stock looks the same as the pictures I’ve found online. The serial # starts with LE instead of the TA like the ones online are. It’s a very low 5 digit serial #. I compared the hammer with a picture of several types of hammers and it has a 9mm hammer in it with a stock 9mm bolt. So my question is, did Colt ever send a model like this out from the factory or has this gun been built by an individual? It has me confused since it appears to be all Colt. All the pins and other places on the rifle appear to be un molested and not wrenched on. I like the looks of this gun, but If it’s not the real deal. I hate spend the same money that I could buy a 9450 or 6951 for.  Thanks for the help in advance.

You should be fine with +p in the CMMG upper. 9mm NATO is approved and +p is close to the NATO ratting. Just make sure you're running a heavy buffer and use in moderation.

My HD set up is Federal 9mm +p+ 115 gr hp 9BPLE. I'm running a heavy Spikes ST-9X buffer, Wolf heavy spring, ramped bolt, and KNS trigger pins. Runs great with but YMMV. Out of the long carbine barrel +p and +p+ hits like a .357 revolver.

OK...I have an two ARs and really wanted a pistol. I have been reading about sub-16" barreled ARs, and decided against going 5.56. I chose 9mm.So, I naturally came to this site, well, because it is the best.  My question after reading through the posts...is 9mmAR.com a no-go? Deceitful posting aside, do they have good products and reliable service? I looked at the site and it seems to have most everything one could be looking for. Inquiring minds want to know.

I ordered a spikes tactical st 9x heavy buffer from them. Showed up in about a week during the holidays. Had no issues with them.

Great. I would like to begin something along the lines of the SiG MPX. I am not sure why they did not go dedicated 9MM mag well...maybe to facilitate the .357 sig and .40 S&W without new uppers...antway, it looks cool..

9mmar has always had good service and fast shipping when I've purchased...

Thought I would throw this in here for giggles. https://www.youtube.com/watch?v=jCcTtBBNOzw


https://www.youtube.com/watch?v=jCcTtBBNOzw

https://www.youtube.com/watch?v=xvLwFDDYY3E

[youtube]https://www.youtube.com/watch?v=xvLwFDDYY3E[/youtube]

https://www.youtube.com/watch?v=xvLwFDDYY3E

Nvm

I don't think I have ever seen people complicate an issue as much as this one has.

No offense to Olympic but after the incident in 2008 where a man's Olympic AR-15 went full auto resulting in his prosecution and Olympic did nothing to help him out (not financial help, no expert assistance)
I wouldn't touch any of their guns with a ten foot pole.  http://www.grizzlygary.com/archive/index.php/t-4353.html

So you are left with the 9mm AR's that take Colt style magazines. Colt style are the gold standard in 9mm magazines.While I have a Colt AR-15 in 5.56 NATO that is 25 years old, Colt's current financial situation
concerned me. I purchased a Stag Arms Model 9 for $825. It has a lifetime transferable warranty uses Colt style magazines, does not need a mag block because it has a dedicated 9mm lower. Magazine cost for a 32 round magazine rang from
$18.00 to $45.00 for the Colt brand. All have worked great. After about 1,000 rounds I liked it so much, I bought another. If it breaks back to Stag it goes.

I just read the entire thread you referenced, and in no way did it compell me to feel one way or the other about Olympic.
I'd have to say I agree with the court's ruling.

Buy a dedicated lower from PSA.  Best money you will spend on an AR-9.  I prefer the Colt pattern but they also make a Glock pattern.  Both have LRBHO.

I'm getting ready to build a 9mm AR. Is this 20-year-old thread still current, with good info?

Edit: whoops, I thought it ended on pg 1. I see I have more reading to do--sorry!