So i took my newly completed RRA 9mm to the range today....Useing winchester/walmart vaulepack 9mm and convered SA uzi mags.....At first it would fail to extract every 3 rounds or so....I started messing with the extractor,ended up bending it almost to the top of the magazine,then i had trouble with the mag block coming loose and riding up into the carrier.Finally i must have hit the sweet spot because after that it ate 250 rounds without a hitch.I got the red dot and back up irons zero'ed at 25yrds.Hopefully ive got all the bugs out.....Its an tackdriver out to 50 yards and has no problem hitting claybirds out to 100 yards when i do my part....But the blowback design is WAY dirtier than my 5.56 AR,I guess thats to be expected...but dam! i can shoot 1000 rounds of wolf .223 thru my AR and its nowhere as dirty as 200 rounds of 9mm thru this one....Recoil is like 85% as much as milspec 5.56 id say....Overall im very happy..........UNDERDOG

I have mine set up to take Sten mags and had no issues at all.  The one thing that worked great for me was to "pin" the magwell adapter.  I have 4 allen screws that go through the lower into the adapter and it does not move.  Granted if you are using a pre-ban lower you may not want to do this!!

[img]us.f1.yahoofs.com/users/c661b06/bc/Sten+project/HighlandMac1.jpg?bcao7z.AJr1IYlb2[/img]

[img]us.f1.yahoofs.com/users/c661b06/bc/Sten+project/HighlandMac2.jpg?bcAp7z.AvOm4fSQk[/img]

Good luck!!

[beer]

Yeah i was thinking of the sten mag conversion,But this is my first AR build so i wanted to keep things simple,,,Is anyone offering a drop in sten mag block for the colt style system?If so does it take unmodded or notched sten mags?....Thanks,UNDERDOG

The problem with a "drop in" sten mag adapter is the sten mags are a good bit wider than the colt/uzi mags.  Sten mag adapters will all be 2 piece.  If you follow the tacked thread at the top of the page it has the whole history we have on this board on how to do it.  If you send me an email I can send you the word file with the full instructions.  The big thing to consider though is do you want to pay $50-150 for factory Uzi/Colt mags or would you rather pay ~$5 for surplus Sten mags that function perfect and do not "volcano"??  You need to answer that for your self.  I am cheap ass sometimes so $5 a mag was me all day long!!  You can doo all the work it takes to set up a Sten mag adapter from a 2 piece JRW mag adapter from Brownells in about 3-6 hours with only a Dremmel tool and some hand files.  I didnt have access to any milling machines so thats how I did mine.  

[beer]

By the way on a Colt style system you notch the sten mags.  That takes about 10 minutes a piece with the Dremmel and a highspeed carbide cutting bit.

You bent the EXTRACTOR? [;)]

About dirt, mine is running cleaner after about 1500 rounds on auto.  The bore and chamber have smoothed up quite a lot.
After I zeroed at 25 yards it's easy to make a ragged 1/2" hole.  It's amazing that it's still accurate after I hacked down the barrel with a bandsaw and reworked it on a lathe.  I forgot to throw a crown on it too, just trued the end.
I had to do some tweaking on the ejector too.  I didn't bend it down but inward until it was lightly rubbing on the bolt.  I did some filing on it too.  I laid the upper half of the ejector face back a couple of degrees.  

Are you using a RRA magwell block?  Mine won't go too far into the magwell due to the mag catch holding it and the ridge up the left side butting into the upper.

Yeah you know what i mean....[LOL] actually i guess i bent it down and in...Yes everything is rock river...Also is there any better triggers that can be used on the 9mm's, what about lighter springs?Any problems with light primer strikes? I guess im spoiled by my 2 stage in my 5.56 ar.....UNDERDOG

I don't know about normal semi-auto AR stuff.
I'd get that that JP Enterprises trigger would be a good single stage with a neutered M16 hammer.  That's the trigger I'm thinking of getting for my M16.  My M16 trigger is pretty decent so I'm not too motivated.

For a 9mm setup, you should be running a normal or heavier than normal hammer spring due to the blowback design.  Also, in case you haven't torn down your bolt, the firing pin is spring loaded.  

The only action related malfunctions I've had, aside from ejection, have been from using a semi-auto carbine buffer or an M4 buffer.  I got some bolt bounce (hammer down on a live round on auto) and a few stovepipes.  If I stick to the steel 9mm buffer then all is well.  It shoots cleaner too.

I noticed that you characterized the recoil as less than 5.56mm.  On semi it does seem like less.  Maybe the action is opening more softly.
On auto, mine jumps around quite a bit more.
I'll hand newbies my 5.56mm setup and not worry too much about it getting away from them.  This 9mm setup bounces around more on auto, especially with decent ammo like Fiocchi and Winchester.

ADDED:
I just notice that you're in VA too.  I'm in Fairfax county and go to Albemarle to shoot every couple of months.  I'd like to see how your setup works with the converted UZI mags and compare my hacked up UZI mag with yours.  If you don't have a Colt mag, I've got a 32 round one.  Last shot hold-open is almost as cool as free ammo!

I belive my springs are at least normal,,but like i said everything feels heavy after the two stage,Yeah i didnt know the pin was spring loaded but i figured it out pretty quick LOL....Im using the 9mm buffer over a standard car recoil spring w/no spacer in a pinned 6 pos stock (pinned to keep the atf happy) and other than the FTE in the begining ive had no other problems....Only got like 400 rounds thru it as of now so well see....Using the winchester because wally world has it pretty cheap,figured id get the bugs out of it then try other types of ammo.....Im in the winchester area,not sure where Albemarle is but im up for it some time....UNDERDOG

Charlottesville is in the middle of Albemarle Co.  

I'm not sure when I'm heading out to blast but I'll send you an email or IM beforehand!

J_E_D I am in fairfax as well.  You sound like a man that knows a lot about these 9mm ar.  I might need a little help.  maybe one day we could head to the range and see what the deal is.  just drop me an e-mail.
Gary

I'm thinking of going to the NRA range for a bit of semi-only UZI mag tweaking on 4 June.  There seems to be a regular AR15.com crowd there from 7-9.

latta_gary, if you've got a place to go shoot besides places like the NRA range and Blue Ridge Arsenal I'd love to go with you some time!

BTT

I like that pistol grip and the side sling adapter.