Trying to start a informational thread that everyone can give details on their 9mm ar's and how reliable they are. Info like what mags, buffers, lpk, bolt ramped or unramped, fire control group's, buffer springs? Stuff like that. Post a pic if you like. If this has already been done please direct me to proper thread and delete this one.




Here is what I'm looking for..
Example

DDLES dedicated lower
RRA 9mm upper
RRA LPK
Bill Springfield FCG
RRA ramped bolt
PWS "Spikes Tactical" ST2 buffer
Metalform mags

When firing the casing is thrown at the 2-3 oclock position any suggestions? Or  is that GTG?

No malfunctions unless trying to bump fire, or fire very rapidly Gonna try a different FCG tomorrow and will report back..

I've got a CMMG dedicated lower and CMMG upper.  It runs 100% flawlessly out of the box with Metalform mags.  Never a hiccup.

With that said... tag.

I'd like to piggyback onto this one.

I am building my first 9mm. So far, I have

Spikes billet upper
Spikes 16 inch barrel
small parts to complete this upper minus bolt
buffer assy with Colt 9mm buffer.

The rest of my build plans are:

DDLES lower
CMMG bolt
Metalform mags from CDNN
Magpul MOE furniture
Magpul MBUS rear sight
Tacpoint optic (for now)

Need a recommendation on a good LPK for the above setup.  I like the stainless LPKs from AIM for 5.56 builds.

Any comments or suggestions?

Is this different than the 9mm AR FAQ's thread?

Yes sorta.... The FAQ doesn't have what everyones setup listed, it describes parts and parts that have been used. I want to be able to judge for myself what most people use to see what works the best..

Here is what I'm looking for..
Example

DDLES dedicated lower
RRA 9mm upper
RRA LPK
Bill Springfield FCG
RRA ramped bolt
PWS "Spikes Tactical" ST2 buffer
Metalform mags

No malfunctions unless trying to bump fire, or fire very rapidly Gonna try a different FCG tomorrow and will report back..

The one main for me was converting to a "colt style" mag adapter (RRA).
And using colt style magazines.

I use C-product, and Promag magazines.  

I can't remember the last time, or even if I've ever had a failure.  I'm guessing not.

RRA Mag adapter.
10.5" RRA upper.
RRA 9MM marked lower (no diff than any other lower)
Heavy buffer.
Ramped the bolt myself with a dremel.
9MM hammer.

This is my first AR in 9mm. Here's all the specs and everything I used or did to it. I've put shelf ammo, reloads, & hollow points thru it and I've had zero FTF in roughly 1200 rounds now. It eats anything that i've put thru it so far.

Specs:

LOWER
- Tactical Machining 80% Lower on a Form 1 - SBR - I did all the machining. Ident Marking Services did the engraving, USA Anodizing did the hard coat andizing. Lower has 9mm NATO markings, Safe/Semi markings
- DPMS LPK
- JP Enterprises Reduced Power Spring kit
- Magpul CTR-M Stock, MIAD Grip & Trigger Guard.
- KNS Pins.
- Hahn Dedicated Mag Block with bolt hold open
- Hahn Sub Caliber Buffer
- Vltor HK Style Side Sling End Plate
- Adjustable Trigger Mod.
- Rear Take Down Pin Spring Mod.

Upper
- Bravo Company Flat Top Upper without ramps.
- Gas Tube Plug Mod. (I drilled, tapped, and plugged the gas tube opening in the upper)
- RRA Bolt ramped by ADCO.
- Green Mountain Custom 8" 3 Lug Heavy Barrel 1/10 twist
- HK 3 Lug Flash Suppressor
- BCM Gunfighter Mod 4 Charging Handle
- YHM Diamond Carbine Length Handguard with endcap.
- Troy Industries Handguard Grips.
- Troy BUIS
- EOTech 552
- LaRue FUG Grip

-Metalform 32rd Mags
-Beta 9mm Mag

http://www.hunt101.com/data/500/medium/9mm_1.jpg

http://www.hunt101.com/data/500/medium/9mm_2.jpg

I have two 9mm AR's, both 16" carbines. One carbine length, one mid length. Both run perfectly, no drama.

Boring details:

Rifle 1) CMMG Mk 9 lower, RRA barrel on standard AR upper with CMMG factory ramped bolt

Rifle 2) Cav Arms Poly lower with RRA MagWell adapter, RRA 9mm  hammer and RRA upper

Both rifles have 9mm RRA type buffers.

Magazine mix:  
CProducts
ProMag
Modified Uzi

NO Metalforms ever tried as the above function just fine.

I have one 9mm SBR

-RRA Dedicated lower
-RRA 9mm upper
-RRA 7.5" barrel
-RRA 9mm bolt, buffer and spring
-KNS Pins
-RRA Charging handle with Badger Tac-Latch
-Midwest Industries SS-Series handguard with CAA vertical handguard
-Vortex Flash Hider
-GG&G mount with Streamlight Poly Tac light
-Ergo Grip
-Magpul CTR stock
-ATN Digital Ultra sight
-Magazines: RRA modified UZI, CPorducts old and new

No failures to feed, extract or fire with FMJ ammo. 1 FTF with 124-gn Hydra-Shok (last round in mag)

Are you trying to infer "reliability" based on the popularity of a component or group of components?

What is done to get a 9mm AR to run reliably has less to do with the components one chooses and more to do with whether they understand the platform and it's quirks enough to address any issues before they arise and correct any issues that come up unexpectedly...

While I understand that what works for some, may not work for others. I just want more Ideas on what I can try to get this thing to run more 100% reliable. Statistics don't lie.. I built the above described gun myself and have a very basic understanding how the blowback system works. I have read the FAQ two times and still reading other info on the net as well..

I have an old school dedicated 9mm Colt AR and don't have any reliability issues. I use CP magazines.

Oly upper, Sten mags, Sten block. No mods, except for good ammo.

Mine are all based on Rock River and Hahn precision parts. Original Colt mags and C Products mags have always run 100%

Uzi mag conversions not so much, I have a couple I marked as problematic others are very good. I only use them for range mags though.

Don't give up on a rifle until you break it in, all my 9mm ARs ran better after a few hundred rounds and cleaning of course.

Just ordered my DDLES lower, so the biggest decision has been made.

Stinger Arms lower(first one I ever bought, it's been used in a few different builds ) with DPMS parts kit, RRA complete 9mm upper, RRA 9mm buffer, Hahn top block, C-Products magazines. 100% since assembly. I haven't shot it past 100 yards, but it does great out to there with red dot scope or BUIS(GG&G A2).


It originally had an EOTech, M4 stock and Tango Down PG, now has MOE furniture all around and an Aimpoint.








(far right)



 

Same. Mine never has any trouble. 100% with all 9mm ammo types. Guess I got lucky.

I think there are a lot of 9mm's out there that run fine. We hear more about the ones that screw up so one could get the impression all 9mm's are bad. Its not the case from what I have seen on my own and have read here. Reading this thread makes me think that there are not as many problems with the 9's as some might lead you to believe.

But then, if you own the 9m that is screwed up you probably feel differently about it than I do.   Now, when I first put my 9mm together I has some minor feed problems. This was a RRA .223 lower with a RRA conversion mag adapter and a 9mm RRA upper. So, the gun was all RRA. I worked with adjusting the magwell adapter and got it all ironed out however. Since then I put all the parts on a CavArms lower I have and it has been flawless since I built it. As stated before my CMMG Mk9 has always been perfect.

No 9mm drama at my house...

LOWER (built by me)
* DDLES 7075 T2.
* LPK: Spike's Enhanced LPK with Battle Trigger Group (rounded hammer) and KNS pins.
* Standard action/buffer spring.
* Spike's ST-T2 Buffer.
* $2.25 in quarters and 1 Twang Buster inside the back of my receiver extension (buffer tube) to help
slow the bolt down so I don't break my bolt catch.
* Mags: Colt branded (Metalform), Metalform, CProducts (modified follower for bolt hold open).
* Magpul furniture.

UPPER (built by Spike's)
* Spike Tactical 9mm Billet upper.
* Spike's 16" M4 profile 9mm barrel.
* Spike's 9mm Muzzle Break 1/2x28 threads.
* RRA ramped 9mm bolt (purchased from and ramped by ADCO).
* BCM Gunfighter Mod 3 charging handle.
* DD AR LITE 10" rail.
* Troy front & rear BUIS
* Magpul furniture.

100% reliable with around 600 to 700 rounds down the pipe.
AMMO: Winchester (115gr. ball), PMC (115gr. ball), Independence (115gr. ball), Federal Hydra-Shoks (147gr. HP).

lower––cmmg 9mm marked lower, RRA LPK, gen 1 pins, hahn dedicated mag block
upper–– TROS 5" barrel, mega upper rec, yhm rails, ramped bolt

runs 100% w/colt and promags.

On bottom:

I've got an old pre-ban slab sided Colt 9mm that I bought used.
It's all stock with the one exception of the KNS pin anti rotation thing.
It came that way so I leave it in. I doubt it will quit running if I took it out, lol.

Never had a single issue with it. Always use the Colt mags that can with it.
I have 7, 2 20s and 5 32s.








Bill

How to make a 9mm AR run reliably?  Start with good parts and assemblies.  Take your time putting it together, tweaking as needed for best fit and smoothest function.  KNOW HOW THE GUN WORKS and especially the way the magazine interfaces with the rest of the system.  Keep it clean.

I have a 16" RRA factory 9mm carbine that required a bit of adjustment of the position of the mag block so it would reliably run CProducts and Rock River supplied modified Uzi magazines.  With that small, easy adjustment, it's been like a well maintained sewing machine.  I built an SBR with a lower from SOG Armory, barrel from Spikes, upper from PK Firearms, and various and sundry other parts from other reliable vendors.  I use the same block that came with the RRA carbine. This also runs wonderfully.  And a 10.5" 9mm is a blast to shoot!

Caveats: not everyone will be able to make every Colt-style 9mm carbine run with every configuration of magazines and ammo.  That's just the way it is.  CProducts magazines were supposed to be a "universal" mag for this gun, but while they can generally be made to work with most guns, they just won't work with others.  Do not mortgage the farm to buy a container-load of magazines until you've thoroughly tested YOUR gun with several samples of the mag you plan to use-and be ready to change plans if you find some consistent problem that's not a one-off manufacturing defect.  And if you can't get the gun to run with both properly modified Uzi magazines and Metalform mags, there is something mechanically wrong with the gun.

If you're building one of these guns, plan on taking plenty of time to test and fiddle with it, and work out every kink before you actually put it to serious work.  And when it finally does work every time, enjoy!

This is the info I was looking for.. Thanks for the reply's.. I plan on tinkering with it but needed more Ideas on what others have done to theirs..

Also mine is a dedicated lower so there is no adjustment to bring the mag up or down..

I stopped in to ADCO a few months ago and Steve put one together for me, out of off the shelf RRA components, that runs great.

16" RRA 9mm upper, RRA 5.56 lower, with the conversion block, 9mm hammer, RRA (unmodified) bolt, not sure about the buffer at the moment, I don't remember and don't have the paperwork on me.  Takes the modified UZI mags.  Second mag I bought had a small defect where it wasn't cut quite enough and the right side of the stack would flip up too much and cause a malfunction.  Got that mag replaced.  The other mags all worked flawlessly so far.  Only about 300 rounds through it so far, but works great.  I have noticed more wear on the sliding surfaces of the bolt than I expected this early on (but I'm brand new to AR-15s, so it might be normal).  If I lube it any more, it just leaks down and gets into places where I'd prefer it not be.

Double Diamond LE Supply Dedicated 9mm T2 lower
Spikes Dedicated 9mm Upper
Spikes (CMMG) Bolt Carrier Group
RRA LPK
Timney Skeletonized Trigger
BCM Gunfighter CH mod4
Spikes ST-9X Heavy Buffer
Wolff Extra Power Action Spring
5" Spike's Tactical Barrel
Spikes 7" BAR
AAC Ti-RANT 9 Suppressor
Magpul B.A.D.
Magpul CTR/MOE Furniture
Aimpoint T-1 w/Daniel Defense Mount
Troy BUIS

Using a few Metalform mags and a few CProducts mags.  Exactly 500 rounds of American Eagle 147gr fired so far, with 2 failures...both of which were caused by the brass catcher getting in the way of ejecting shells.



Then I made a few changes...

OUT:
Daniel Defense T-1 Mount                
5" Spike's Barrel  
Magpul MOE RVG                              

IN:
Knights Armament QD Mount
4" Lothar Walther Barrel
Gear Sector ASP Sling
Magpul AFG2
Lula SMG mag loader...a must.

Ok I think I got it pretty much figured out. I put a Daniels Defense FCG and it passed function test. The only thing is it is a notched hammer, which some people say will not work. It fires appropriately, and only had a couple failure to eject all the way out, and that was out of 200 rounds that I will say is due to the cheap ammunition "cci blazer 115grain" and prolly not being oiled enough, but that is another question I will ask towards the bottom of this post. Yes I always load 1 then shoot, then load 2 then shoot, then load 3 then shoot, then load full mag. I do that to make sure the BHO is functioning properly. I checked the extractor on the bolt as some have suggested, and it looks fine and it tight.

My next question is how wet "oiled" does a 9mm like to be? At this time it is a little dryer than I normally run my 5.56 ar's. Thanks again for all the help..


ETA to add Pic's

RRA upper and bolt


Hahn block


Metalforms


KNS pins


DPMS LPK





I have run this in a few different lowers and Never had a problem with the metalforms. It runs 100% all the time with this setup.





As a pistol piloted by Wesmerc











or as a rifle









 

I believe I got mine figured out. I believe mine was the cheap blazer ammo I was using. It ran 3 full mag dumps of Winchester 115 grain.

I put together my 9mm SBR using the following:

RRA 9mm upper
RRA stock bolt (un-ramped)
TROS 5" 3-lug bbl.
BM carbine lower
Hahn 8 oz. buffer
RRA 9mm buffer spring
DPMS hammer (initially I used an RRA 9mm hammer)
KNS anti-rotation pins
VM Hy-Tech mag block using unmodified UZI mags
DD 7" M4 rail system
Troy folding F&R battle sights

It runs 100% w/any ammo used however, I use mainly my 147 gr. sub-sonic reloads due to using a Trident-9 suppressor in it.

Cheap aluminum case Blazer or Blazer Brass?  I don't think the aluminum case Blazer is "recommended" for use in blowback actions - some people claim it runs fine and others have problems with it.

It's the cheap alumnium case. Wish I woulda knew before I bougtlht 1k rounds. Oh well I got a buddy that can use them.

That ammo works just fine in most handguns - run it through your glock or whatever else you have...