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Posted: 8/13/2003 7:20:22 AM EDT
I’ve read the FAQ, but still have some questions. I’m again thinking of getting a 9mm and am leaning towards the RRA.

Will the RRA upper work on a standard AR15 lower, or do I need to replace anything on the lower like the hammer?

If I use the RRA complete upper, do I just need the RRA magwell adapter? Does this adapter allow the use of Uzi mags or Sten mags?

Do the mags require any modification? If so, how difficult is it to modify the mags and where can I get a template/pattern that shows how to modify the mags?

Where can I purchase mags for the 9mm AR?

Will the bolt hold open after the last round is fired?

Are the mags in the RRA system released by pressing the regular mag release button?

What are some of the most common problems regarding the 9mm ARs?

Thanks in advance for your help and guidance.
Link Posted: 8/13/2003 8:07:09 AM EDT
Bookhound, I don't own one (yet) but I can answer some of your questions: RRA will work on standard lower if you either 1. replace the hammer with the RRA 9mm hammer or 2. get the bolt "ramped." JoeBlack on this site will do it for $70 IIRC. With a ramped bolt you can use any lower with a standard hammer. If you try to use the upper w/o doing either of these, the bolt and hammer will bind up on each other... RRA magwell adapter allows use of uzi mags (and the very expensive colt mags). A few people have managed to modify the now out of production JRW mag block to use sten mags (see the posted thread about this) IMHO, just go with the RRA block. Uzi mags require a notch...you will have to ask others how to go about doing this, as I don't want to steer you wrong and have you ruin a magazine! try Vector Arms or Cole Distributing for magazines- both have pretty good prices from what I understand. You can also sometimes find modified mags on the Equipment Exchange or even at gunbroker.com and some of the other firearms auction sites. The RRA mag block will allow the bolt hold-open to work IF you are using the Colt magazines. Uzi mags will not actuate the bolt hold open. Of course, Colt mags run about $100 for used ones, Uzi mags can be had for as low as $20... As I understand it, the mag release button will drop the mag... Like I said, don't own one, but my understanding is the most common problem is failures to eject/extract (most common problem with blowback type weapons from my lmited experience). Hope this helps! Dawg
Link Posted: 8/13/2003 8:56:11 AM EDT
Thanks so much for your reply. It was very helpful.
Link Posted: 8/13/2003 12:08:48 PM EDT
[Last Edit: 8/13/2003 12:10:28 PM EDT by LightningLink]
Here's some thoughts on the subject. First, the RRA upper. If you order it through a dealer, you will save around $40-50, but it seems to take a while. Anywhere from 6 to 8 weeks. Check the Sableco thread below to see how long some have been waiting. I ordered my custom 9mm upper direct from RRA and received it in about 12 days even though they told me it might take around 4 weeks. "Will the RRA upper work on a standard AR15 lower, or do I need to replace anything on the lower like the hammer?" I used a Century C-15 lower with an RRA parts kit for my build. I found that the rear takedown lug on the upper would not fit quite right in my lower. It did fit fine in a Bushy lower I had on hand. I ended up doing a little filing on the upper as I couldn't really work inside the lower to make it fit. So, depending on the lower, their could be minor fit issues, but I would say very unlikely. Dawg180 pretty much summed up the other questions. I accidentally cycled the bolt on mine with the standard hammer installed and sure enough, it locked up. I had to remove the stock to get the bolt unstuck. So unless you ramp the bolt, you certainly want that 9mm hammer installed. My understanding is that ramping the bolt is a good idea anyway, but I'm not sure how hard it is to do with household tools. I just recently completed a Sten-mag build using the modified JRW magazine block. Just last weekend I put 100 rounds through it without a problem. Unfortunately, like Dawg180 said, these blocks are discontinued and Brownells shows them out of stock as well. Barring the JRW/Sten mag setup, the modified UZI mag system is probably your best bet for cost effectiveness. I'm not sure about notching the UZI mags, but for the Sten mags I simply turned the mag catch out of the way, put the mag in until it touched the bolt, scratched an outline of the mag catch hole onto the magazine and then cut the notch. It takes a little tweaking but it's otherwise easy using a drill and a Dremel. Good luck on your project. One last thing: "What are some of the most common problems regarding the 9mm ARs?" Hehe, not having enough ammo ... it goes fast [:D] LL
Link Posted: 8/13/2003 12:39:43 PM EDT
[Last Edit: 8/13/2003 5:04:42 PM EDT by SBR7_11]
Originally Posted By BookHound: Will the RRA upper work on a standard AR15 lower, or do I need to replace anything on the lower like the hammer?
View Quote
[blue] It is for any AR-15/M16, providing the pivot and take down pin holes are in spec with each other (upper and lower) With the std bolt, and for semi-auto operation, you will either need a 9mm hammer, or a M16 style with the lug removed. I chose the "de-lugged M16 hammer", some lower parts kit come with this style-- [img]http://www.imagestation.com/picture/sraid58/p7a21929478de21856da2653f457a76fc/fc681fb2.jpg[/img] If you "ramp" the bolt, any hammer is fair game for semi-auto operation. If doing Full-Auto, you use std M16 parts in the lower.[/blue] This pic shows the std 9mm bolt-red circle shows the groove that binds the std "notch faced" 223 hammer and locks up the works, and the blue line shows the ramp cut as done by [purple][b]joeblack[/b][/purple]. (photo courtesy of [purple][b]joeblack[/b][/purple] also)- [img]http://www.imagestation.com/picture/sraid69/p0fc65b71a283602f378d39bc27d8baeb/fbb7fbdb.jpg[/img]
If I use the RRA complete upper, do I just need the RRA magwell adapter? Does this adapter allow the use of Uzi mags or Sten mags?
View Quote
[blue] Many choices here, but the Colt pattern 1 piece blocks (Colt-RRA-ASA-HAHN) allow use of Colt mags (big bucks),, or Uzi mags with a notch cut in them to allow them to use the AR' mag catch. To use Sten mag in the Colt system, you need to modify a 2 piece block set (refer to [url]http://www.ar15.com/forums/topic.html?b=3&f=15&t=136191[/url]). I chose to do the Hy-Tech block, no need to spend extra $10-20 per mag for notching, run with plain Uzi mags (refer to [url]http://www.ar15.com/forums/topic.html?b=3&f=15&t=159208[/url]). I even have a repair/mod thread at top for the Hy-Tech block. This block is held via the AR catch, mag change via button on the block.[/blue] [img]http://www.imagestation.com/picture/sraid73/pc3f559fe67d9e6ffa756a42fd5888d30/fb6773cd.jpg[/img] Here is a pic with a Uzi magwell attached to a home made block set-- (courtesy of AR-Fan): [img]http://www.imagestation.com/picture/sraid71/p79abaea0cec3c4b3bf03df02172d7907/fb9aa69f.jpg[/img]
Do the Uzi mags require any modification? If so, how difficult is it to modify the mags and where can I get a template/pattern that shows how to modify the mags?
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[blue] It is just a matter of getting the mag to correct height, and cutting the slot in correct location. Lee Minor will do for $10 ea, but you need to send the block you are using to locate the hole correctly with the block, he has reported a high degree of variation between blocks and makers- [url]www.lrmfirearms.com[/url][/blue]
Where can I purchase mags for the 9mm AR?
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[blue] Uzi mags about anywhere, Colt mags are slim picking, expect to pay $125+ per for a 32 round Colt part.[/blue]
Will the bolt hold open after the last round is fired?
View Quote
[blue] With a block that does offer the feature, and if a Colt mag is used. Some require a 9mm catch, other will operate the 223 catch.... Uzi mag does not operate a hold open device... count your shots.. [/blue]
Are the mags in the RRA system released by pressing the regular mag release button?
View Quote
[blue] If using a Colt pattern block, and Colt mags or notched Uzi mags,,,, yes. If using the Hy-Tech block, then the mags are changed via Uzi mag release-- see pic above. [/blue]
What are some of the most common problems regarding the 9mm ARs?
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[blue] 1- Getting the mags notched in correct location, causes feed problems, too high, and shell will tap the lip on the mag and try to eject before hitting the ejector. 2- Ejectors need to be visually verified that it is correct relation to the bolt. Have found headspace to be a factor to running problem in 2 rifle, maybe a 3rd, I think he sent his back to RRA. 3- Colt mags like to unload themself if loaded and dropped or bumped, seen this happen to a shooter at the Richmond-IN shoot recently-- rounds just spit straight up out of mag while making a "ZIP" noise. Other problem is running out of ammo/not having enough, as 9mm is cheap to shoot, and is a blast, especially with a suppressor.[/blue] Pic w/out suppressor: [img]http://www.imagestation.com/picture/sraid73/p02f2d2fe90c7bf99ac019753a95c9779/fb6773d3.jpg[/img]
Link Posted: 8/13/2003 1:19:56 PM EDT
[Last Edit: 8/13/2003 3:17:06 PM EDT by joeblack]
You are thinking correctly, but pass on the RRA mag well adapter.... My set up is a ASA mag well adapter. ASA slips, nice snug slip fit, down into the mag well and stays in place. The Colt style (RRA!!) is too sloppy and doesn't repeat, POS in my opinion. Plus you have two pins in the adapter that rub the hell out of your lower in the Colt style. Pics show the 6" 9mm upper and the 6" 9mm upper with a UZI coastal can. To get mine to run flawlessly (72 round mag dumps, 40 rnd mag dumps, and 32 round mag dumps) I had to: Cut a 16" RRA barrel to 6" and thread it 1/2-28, throat the entrance to the barrel chamber, grind head space slightly, ramp the bolt, use the .223 hammer, grind leads into the mag well adapter feed ramp, and correctly modify mags (UZI and others) to fit the M16 mag catch. (All this I did at work!![:D]) [img]http://users.zoominternet.net/~picplace/M16A19mm.JPG[/img] [img]http://users.zoominternet.net/~picplace/M16A19mmcoastal.JPG[/img] M16 is shorter than my UZI SMG!! [img]http://users.zoominternet.net/~picplace/M16anduzi.JPG[/img]
Link Posted: 8/13/2003 3:39:49 PM EDT
WOW! Thanks, guys, for all the info and the cool pictures. Now I have to get one of these for sure. Again, I appreciate your help.
Link Posted: 8/13/2003 10:24:45 PM EDT
JoeBlack, That middle pic in your reply- are you using MP5 mags in an AR-15 setup???
Link Posted: 8/14/2003 3:01:26 AM EDT
joeblack, Why did you have to “[b]throat the entrance to the barrel chamber, grind head space slightly…grind leads into the mag well adapter feed ramp[/b]”? I wouldn’t know where to start on this kind of stuff. Are you saying if I buy a RRA upper I might have to make some modifications like these to get things to work? Also, where can I find an ASA well adapter and about what should it cost in US dollars? Thanks SO much!
Link Posted: 8/14/2003 3:40:53 AM EDT
[Last Edit: 8/14/2003 3:51:48 AM EDT by joeblack]
Originally Posted By Dawg180: JoeBlack, That middle pic in your reply- are you using MP5 mags in an AR-15 setup???
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Walking around a gun show I found this mag for $5.00. Pulling out my trusty digital calipers, it measured like a UZI mag. I just needed to slot it. It's not a MP5 mag, I forget the name... There was a link of the name of this mag on the M16 side, but I forget the name....
Link Posted: 8/14/2003 3:45:14 AM EDT
Originally Posted By BookHound: joeblack, Why did you have to “[b]throat the entrance to the barrel chamber, grind head space slightly…grind leads into the mag well adapter feed ramp[/b]”? I wouldn’t know where to start on this kind of stuff. Are you saying if I buy a RRA upper I might have to make some modifications like these to get things to work? Also, where can I find an ASA well adapter and about what should it cost in US dollars? Thanks SO much!
View Quote
All the tweaking I did was just to remove any slight miss feeds or non ejected cases. I've run over 1100 rounds with out one miss feed or non ejected case. (yes, I'm counting) You will be good to go with the RRA upper and the ASA, American Spirit Arms, mag well adapter. ASA [url]http://www.americanspiritarms.com/[/url]
Link Posted: 8/14/2003 4:04:09 AM EDT
Thank you so much for the link. I'll take your advice and pick up one of the blocks.
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