Could someone please provide some info on the RRA 223 Wydle Chamber. Does it shoot surplus ammo well? What about the lighter bullets, medium weight? Does it cause feeding problems? The barrel has a 1:9 twist. Specifically talking about an A4.

If you do a search for "Wylde" you'll find many threads related to this topic.  Basically, you can use any .223 or 5.56 ammo in a Wylde chamber with no problems.

That has been my experience also and I have a RRA M4.  It goes bang every time regardless of what I feed it.

Ahhh...interesting. I was under the impresion that the M4 barrels had the 5.56 chambers and that all the other barrels used by RRA had the .223 Wylde chamber!?  here's the info that the Maryland AR-15 Shooters site has on it:

Rock River Arms (Cleveland, IL):


Chrome Lined Barrels & Chambers:  Right now (Dec 02) they are only offering chrome as an option on the M4 bbls...+$30 for the upgrade. They did do small batches of chrome on other barrels, but as supplies of them have run out, they have decided not to offer, at least at this time, chrome lining other than on the M4s. (info courtesty of: Sluggo of AR15.com)

Chamber Type: M16 (chrome lined M4 barrels) & Wylde (on all others)

B9

RRA M4 have the 5.56 NATO chamber, all other models are 223. also have m4 feed ramps

did a search, and only found this post.
does anyone have a RRA with this chamber?

got it on my RRA 24" varmint.  will finally get to shoot it this weekend :)

http://talk.shooters.com/room_3/615.cfm
http://www.radomski.us/njhp/cart_tech.htm