This whole 9mm AR thing has me tied up in a corner here...If i go with a rock river set up for the upper half can i swap to a different mag set up than UZI <if it doesent work out or would i need a different bolt....? other than that im thinking the 9mm AR needs to be reinvented do you guys think the same? It was looked at the wrong way i think "comming from a mechanical stand point" they designed it around the AR platform i think it should have been designed around a pistol platform and then put in to an AR ....just my thought .....Would it be a good idea to wait a couple more years untill this 9mm thing gets all worked out? before i get in to it? Ok so if im to build one what would the best way to go about it DETAILS... Eliminate this whole colt thing...if i did go with the rock river upper set up is the magwell adapter disscussed at the top of this board the BEST so far the HYTECK? i do like the feel of the uzi mags i have ..they feel strong and not sticky as far as reliability goes ...i want a good system ....convince me.

OK..
You have decided to do a 9mm AR but are tossing around the various options.

The RRA upper Assembly is the way to go if money is a issue. If money is not a issue you can purchase preban COLT uppers halves for around $650.00.   I don't have a issue with money but I still went with a RRA upper.  It is a exact copy of the COLT.

The problem that people are having is the the MAG adapter and with MAGS  not with the other parts(uppers).

ALL adapters have some issue or another even the factory colt adapters require a little tweaking.
The HYTECH adapter is THE BEST way to go IMHO if you will only use UZI mags.  But it will not be compatible with COLT style mags. It excels because you do not have to modify the UZI mags to work.  There are a couple bugs explained in the sticky at the top, but once you work them out it is a GREAT adapter.
I went with a GARRISON mag block.
It is VERY similar to the ASA block.  It drops in from the top.  The only difference between the ASA and the Garrison is that the Garrison does not use the transfer block method for the bolt open.  You must use a 9mm mag catch for the bolt open to work.
 Like ALL the adapters, you must use COLT style mags for the bolt hold to work. NONE of the adapters have a bolt open for UZI mags.

I am awaiting a 9mm buffer which will be in this week before I do more testing.

I believe that the weapon will run as is once I get the buffer.

If you want a weapon designed around a pistol then buy a HK94/SW5/MP5.  You want a real gun, buy a AR.

Oh i alredy own 5.56 AR's i was tinking around getting in to the 9s   I WOULD LIKE TO CALL IT A ......[blue]AR5[/blue]....MP5&AR 15 mixed together /sounds good to me\  but any how if i get the HYTECH mag block then every things cool? with minor adjustments i take it ...dont worry about me i have a machinists back ground + im just good with guns in general..and plenty of common sence..so i guess it shouldn't be a problem...the main thing i want to stay away from s DRILLING holes or making alterations to the lower incase i want to use it for other gun creations like a 458 socom for instance ...well i have a 9mm rock river barrel and some uzi mags already thanks to the EE board ..just need some more pieces..

Spent,..If your leaning to the HyTECH block.,Then your set...Read the HYTECH thread for any problems with that and get an Upper rec. and bolt and your good to go...Trust me you WILL love the AR platform in 9mm...UNDERDOG

The Hy-Tech block is a go from the moment you get it...... stick it into gun... it is held to correct height via mag catch.... and the mag seating is built into the block.

The mag seating height is also built into the block, so just slide a Uzi mag in and fire, just be sure to verify ejector is set to correct position, mine was a go out of the box.

Just small details needed to add to the utility of the block, but is a "plug & play" from the start,,,,,, read the tacked thread above about the "Hy-Tech repair/fitting", and read this item, basically a re-do/slight more info about the block,,,, thank Ken ("quarterbore" for assembling and hosting the page.......

[url]http://www.quarterbore.com/ar15m16/hy-techblock.html[/url]

The only reason I went with the Garrison block was because I wanted the completed weapon to look as much like a factory COLT setup as possible.

As you can tell above, HYTECH is the way to go.
No hassles with notching your mags to make it work.  Basically plug and play compared to the rest.

Now, if you are LEO then go with a garrison and get LEO colt mags...

I've got the RRA upper with an ASA mag block, I hadn't heard of the Garrison at the time, and it is great.

I bought one UZI mag with the mag block and I had more, all IMI, modified by my local gunsmith.  They all fit and function really well.

I'm like drugrnner, I didn't like the look of the mag block hanging out of the receiver, but that's just a cosmetic thing.

Once you shoot it at the [u]INDOOR[/u] range you'll be hooked.