9mm AR?

[Smith]

So I have a lower sitting around and PSA's AR9 looks interesting and got me thinking. However, I know nothing about 9mm AR's. I've seen the dedicated Glock lowers, but don't really care about that aspect. I'm really just looking for something to shoot my 9mm ammo through that keeps the AR flexibility for the future. Really liked the Uzi I had but that's another beast.

So, school me on what I need to know. Are all 9mm AR uppers the same? Standard AR uppers OK, or is there a reason to get the dedicated 9mm upper? What's the deal with notched hammers? Do the adapter blocks work?
Does ammo choice make difference?
Barrel length?
Mag options?

Probably staying pistol configuration, thinking 10"? Not worried about suppressor's.

[RED333]

Wait for Dolomite to chime in, he built one for his better half.

[Westwindmike]

I have a 9mm AR and it's my favorite. I shoot mostly cast boolit reloads in it. It feeds anything and everything from super light loads to max.

[R1100R]

Vince has one too. I'm looking real hard at this also.

[KKing]

I've been eyeing the PSA kits myself. I'm in for some info

[DMark]

After all of the beta testing I did free of charge for PSA getting my PA10 in .308 to run right......, I'm going to let somebody else work the bugs out with the Palmetto State AR in 9mm.  :ugh:

 

I understand that the kit is coming with an non ramped BCG and a regular (non 9mm) hammer.

 

BUT!!!!!!

 

Once all of the fixes are in I'll have to have one.   :cool:  

[Smith]

Well, from what I can gather it is plug and play like any other AR upper. The only real issues is when you want to use Glock mags and then you have to have a special lower to get the angle right, a special bolt carrier to clear the mag, and a special hammer that works with the above.
Does anyone know if there is any difference in mag brands? I can find c-products for under $14 and colt/modified Uzi mags for up to $45+.
I don't count the Promags ;-)

Do the PSA mag adapters have a lrbho? Edited January 4, 2015 by Smith

[Smith]

After all of the beta testing I did free of charge for PSA getting my PA10 in .308 to run right......, I'm going to let somebody else work the bugs out with the Palmetto State AR in 9mm. :ugh:

I understand that the kit is coming with an non ramped BCG and a regular (non 9mm) hammer.

BUT!!!!!!

Once all of the fixes are in I'll have to have one. :cool:

Yeah, that's what has me a bit cautious as well. Non ramped and standard hammer aren't compatible, from what I've read.

[MacGyver]

I run one of the Glock mag based lowers. You're right that you've got to profile your bolt carrier to let it clear the feed lips. But, I love the platform.

The Glock based design does have a bolt hold open option. Mags aren't cheap, but they're reliable and cheaper than Colt mags. And, no one ever complains about factory Glock mags.

I run a milspec hammer.

You're welcome to check it out if you like.

[Lumber_Jack]

Read this. It's a good breakdown of building a 9mm AR

http://www.pariaharms.com/AR9.php

[Johnny Rotten]

I've been thinking of doing this for quite awhile , I'm afraid of beating the snot out of a irreplaceable lower..

[RWF]

it is not a kit, but the wife has CMMG 9mm carbine (not a pistol) that's a ton of fun. with front sight removed and a 15" float tube and a red dot.

Edited January 4, 2015 by RWF

[TN-popo]

I have a 9mm AR and it's my favorite. I shoot mostly cast boolit reloads in it. It feeds anything and everything from super light loads to max.

 

Can you tell me more about it?

I really want a 9mm AR and have been waiting for the SIG MPX, but I'm starting to get irritated.

[Lumber_Jack]

have been waiting for the SIG MPX, but I'm starting to get irritated.

Kind of like waiting for the Titanic to come in

[LawEnforcementSalesTN]

I'm really liking that new CMMG Mk9 for an out of box 9mm... has a nice keymod rail, dedicated lower...  I've transfered a few over the last 4-6 months and I really like their pistol setup.  So much that reading this thread and pondering this evening you guys just made me click the order button for one myself !! ;o)  I plan to cut the barrel back to 4-4.5", open the rail up a hair and recess a Octane HD inside .. love that HK SD look.

 

I've built several 9s over the years using all kinds of mag blocks, top loading. bottom loading.. my favorite block is an old VM Hytech from years ago (company went out of business).. many don't like them because of the secondary mag release but I like em b/c you can pick up surplus Uzi mags that don't require modification.  Just old school if you were around when they were popular and back in the day they were the cat's ass unless you wanted to go the hassle of using Colt's 2 piece block.  If you have to use a block, HAHN currently makes the best IMHO .. use to be the bottom loader was the only BHO version but I believe that may have changed in later versions.  I had a HAHN top loader that required the AR bolt release to be removed for it to be used..

 

My distrubutor only had a few MK9 complete pistols in inventory, the upper alone was out of stock so with that being said, I probaby WON'T be needing/using the complete dedicated pistol lower assembly.. so watch out if you're interested as it may hit the firearm board in a few days....They're very nice dedicated lowers and while I'd much prefer to use it and concur with Dolomite, I have that VM block and a several post sample lowers already I just don't need to pull another title 1 off the books and turn into something that limits my resell down the road... and while I can't bring myself to NOT have it full auto well... since I can ;o) .... I do have a post DIAS I machined that might find it's way inside if I grow tired of the VM.

 

Only thing I can say about a 9mm that I've found has suprised a few customers when we build, they do run MORE than a 556.. so it's going to be hard to get a $600 9mm that looks good.  You'll easily be up into $8-$1000 in a blink ... barrels usually run a good chunk more, bolt carriers are twice the cost (for the ramped/machined versions) .. mags are higher, buffer,  etc... it just adds up quickly.. seen a few people be disappointed because they expected it to be cheaper.. even if everything was the same you have the extra of the mag blocks (HAHNs run about $200) or dedicated lowers (CMMG dedicated lower alone MSRPs at $380).

[Westwindmike]

Can you tell me more about it?

I really want a 9mm AR and have been waiting for the SIG MPX, but I'm starting to get irritated.

I can't remember all that much about it. Don't know what brand upper it is. I do know that the bolt is not ramped and I do have the 9mm hammer. It has a mag block that secures with an allen wrench and uses Colt pattern mags. It has last shot hold open, but that rarely works. Don't know why. I bought the upper, mag block and mags from a member on here, slapped it on a Double Star lower and went to blasting. Wish I could remember more details for you.

[Johnny Rotten]

I'm really liking that new CMMG Mk9 for an out of box 9mm... has a nice keymod rail, dedicated lower...  I've transfered a few over the last 4-6 months and I really like their pistol setup.  So much that reading this thread and pondering this evening you guys just made me click the order button for one myself !! ;o)  I plan to cut the barrel back to 4-4.5", open the rail up a hair and recess a Octane HD inside .. love that HK SD look.
 
I've built several 9s over the years using all kinds of mag blocks, top loading. bottom loading.. my favorite block is an old VM Hytech from years ago (company went out of business).. many don't like them because of the secondary mag release but I like em b/c you can pick up surplus Uzi mags that don't require modification.  Just old school if you were around when they were popular and back in the day they were the cat's ass unless you wanted to go the hassle of using Colt's 2 piece block.  If you have to use a block, HAHN currently makes the best IMHO .. use to be the bottom loader was the only BHO version but I believe that may have changed in later versions.  I had a HAHN top loader that required the AR bolt release to be removed for it to be used..
 
My distrubutor only had a few MK9 complete pistols in inventory, the upper alone was out of stock so with that being said, I probaby WON'T be needing/using the complete dedicated pistol lower assembly.. so watch out if you're interested as it may hit the firearm board in a few days....They're very nice dedicated lowers and while I'd much prefer to use it and concur with Dolomite, I have that VM block and a several post sample lowers already I just don't need to pull another title 1 off the books and turn into something that limits my resell down the road... and while I can't bring myself to NOT have it full auto well... since I can ;o) .... I do have a post DIAS I machined that might find it's way inside if I grow tired of the VM.
 
Only thing I can say about a 9mm that I've found has suprised a few customers when we build, they do run MORE than a 556.. so it's going to be hard to get a $600 9mm that looks good.  You'll easily be up into $8-$1000 in a blink ... barrels usually run a good chunk more, bolt carriers are twice the cost (for the ramped/machined versions) .. mags are higher, buffer,  etc... it just adds up quickly.. seen a few people be disappointed because they expected it to be cheaper.. even if everything was the same you have the extra of the mag blocks (HAHNs run about $200) or dedicated lowers (CMMG dedicated lower alone MSRPs at $380).

would you build a 9mm on a transferable lower?

[87toy]

Well, from what I can gather it is plug and play like any other AR upper. The only real issues is when you want to use Glock mags and then you have to have a special lower to get the angle right, a special bolt carrier to clear the mag, and a special hammer that works with the above.
Does anyone know if there is any difference in mag brands? I can find c-products for under $14 and colt/modified Uzi mags for up to $45+.
I don't count the Promags ;-)
Do the PSA mag adapters have a lrbho?

Products mags are garbage, with that said paying 45 dollars for modded Uzi mags is silly.I have 11 bucks each in mine.

My 4.5" barreled suppressed 9mm ar goes out every time I shoot. Love it.

[87toy]

I have been using CProducts 9mm magazines exclusively with mine for 10+ years without issue. I had originally used ProMag magazines but realized they were junk when the feed lips started cracking and breaking.
I think it depends on the individual weapon. If you decide on a Colt pattern gun I would buy a CProducts magazine or two and try them. Then if they work I would buy more.
Something else people may not know is the Colt pattern guns can also use Uzi magazines. You just have to cut the slot for the magazine catch into the magazine body. The bolt hold open will not work with Uzi magazines though.

I may have spoken too harshly. I only tried one cprod mag. It didn't function well for me at all. If the bolt was dropped on an empty mag it would shave a big hunk of plastic off the folower, over and over.

After switching to modded Uzi mags, I literally can't remember having any malfunctions.

[Smith]

Well I ended up getting a Spikes mag block and the upper and bolt from Tactical Ambush. I've had good experience with their 308 barrel and parts so I figured I'd give them another shot. Plus their bolt is ramped and the NiB price was pretty decent.

I'll let you know how it runs when everything gets here. Edited January 6, 2015 by Smith

[LawEnforcementSalesTN]

would you build a 9mm on a transferable lower?

JohnnyR, I would just be sure the bolt is a ramped model and I'd also run a set of KNS anti walk pins. 9s use to beat up a lower pretty bad back in the day but that was mostly before ramping.

But I use to run a VM setup on my M16A2 transferable I had back in 2004/5.

I can mill Uzi mags to work with colt pattern if anyone needs this done. I did this on my last Hahn setup I had.

[Johnny Rotten]

JohnnyR, I would just be sure the bolt is a ramped model and I'd also run a set of KNS anti walk pins. 9s use to beat up a lower pretty bad back in the day but that was mostly before ramping.

But I use to run a VM setup on my M16A2 transferable I had back in 2004/5.

I can mill Uzi mags to work with colt pattern if anyone needs this done. I did this on my last Hahn setup I had.

Is this the upper your talking about? http://www.righttobear.com/CMMG-Mk9-PDW-9-Complete-Upper-9mm-KeyMod-Rail-p/90b3bf0.htm
I have K&S pins on it already, I was really concerned about my lower when I bought a Gen 5 shrike upper but I feel really good about that set up now.
I've heard internet horrors of egg holed FA lowers using 9mm uppers hence me in concern mode again, by using the upper above with a ramped bolt, Hahn mag block( how do they mount? top/bottom? what prevents it from moving?), do I need a different bolt catch? the colt mags hold 32 what does the uzi hold?
Thanks JR

[LawEnforcementSalesTN]

Is this the upper your talking about? http://www.righttobear.com/CMMG-Mk9-PDW-9-Complete-Upper-9mm-KeyMod-Rail-p/90b3bf0.htm
I have K&S pins on it already, I was really concerned about my lower when I bought a Gen 5 shrike upper but I feel really good about that set up now.
I've heard internet horrors of egg holed FA lowers using 9mm uppers hence me in concern mode again, by using the upper above with a ramped bolt, Hahn mag block( how do they mount? top/bottom? what prevents it from moving?), do I need a different bolt catch? the colt mags hold 32 what does the uzi hold?
Thanks JR

 

 

Yep that's it

 

Hahn makes both a bottom loading (probably what you want) and a top loading mag block.  The top loader is considered more a permament setup b/c while they both work the AR's BHO catch, the top loader requires you to install the catch AFTER the block has been inserted.  The top loader is considered more dependable since it can't fall out under any circumstance outside a castrophe.

 

I have used both and never had an issue with a bottom loader.. given you're probably going to want to remove the block and then shoot your 5.56 back and forth, it's probably a better option. It secures with set tension screws from the inside.. nothing permament with either block though.

 

The BHO option works on both Hanhs as long as you have a Colt style mag.  The Uzi mags reguire milling a mag catch slot but will work fine but as Dolomite discussed, they will NOT operate the BHO mechanism b/c of their follower shape/size.

 

I have both 25rnd and 32rd Uzi mags.  Every now and then you can catch them for $9-$10 surplus ... the Colt mags are high and certain years demand a premium ... not sure the significance...  Cproduct mags work well too as others have suggested and are the colt pattern.

 

Your factory bolt catch will work with the Hahns.

 

This VM Hytech uses factory Uzi mags but adds a secondary mag release at the bottom.  Good in the mags don't have to be modified but there is no BHO and the secondary mag release give some the weebeegeebees.. .me, I only shoot my 9 when I'm out having fun so I've never had a problem getting too trained on the other.  But I do see pros and cons with each setup.

 

The CMMG Mk9 lower is a completely dedicated 9mm lower that uses colt pattern mags.  There is no block it's machined into the lower and is ONLY a 9mm lower.. I like the dedicated lowers and hadn't seen those quarter 10s .. they look damn good and would be my choice if I was building a dedicated setup.  Beautifully machined no doubt.

[Dolomite_supafly]

I ramped my own bolt. Took about 15 minutes with a set of jeweler files.

[87toy]

I ramped my own bolt. Took about 15 minutes with a set of jeweler files.

I would love to hear more about this. That's a surprising amount of material to be taken off with jewelers files in a month, let alone 15 min.