I just recieved a RRA mid-length upper minus B/C/CH. I put the new Colt LE/MIL enhanced bolt group in, added ARMs #40, and went to the indoor range. First three in one hole and 3/4" R @ 25. Cool.

This is a HEAVY barrel upper, pig thick under the handguards. I like the increased sight radius, much improved. Really keeps muzzle down compared to my m4. As a matter of fact I'm going to sell the new m4 upper I had saved.

What is the new bolt group? I havent heard of such a thing.

I really enjoy my midlengths as well.

[url=http://www.imagestation.com/album/pictures.html?id=4291852505]picture link here[/url]
[img]http://www.imagestation.com/picture/sraid19/p587e439f12b7bbf4a4ee2b57dfb15aa7/fdc3717e.jpg[/img]

Fortunately I put this on a preban updated with a new RRA 6pos stock. Its a handy piece. I measured the RRA upper as compared to my m4 14.5 upper with a Vortex(new type) on it. The RRA mid-length with a2 flashhider is less than an inch longer.

I really like the increased sight radius, and the weight. The m4-ish feed ramps they cut in were a nice touch. Unfortunately am limited to 68gr or so because of the 1/9 twist. Still waiting for a ACOG 31F. Middies have a reduced peak pressure, which enhances reliability and lessens wear. An additional 1.5 inches of barrel extends the ideal lethal range a bit.

For a shooter that will see more use. I'm going to get another one, with a chrome lined barrel, and send it off to get re-profiled under the handguard like an A2. Then add my Comp2 and some rails to the handguards.

The only thing different about the bolt group is the bolt. It has an slightly different shapped extractor, different spring, and a O-ring.

This is the type of carbine the Marines should of updated to, instead of the m16a4. Well OK a 16&11/16" barrel so they could correctly mount a bayonet.
 

I stand corrected. Digging through random crap today in garage, and found a greasy M-9 bayonet. It mounts perfectly to the preban midlength. If you absolutely must mount a sharp chunk of metal to your carbine, this is the one for you!

sar3k: I put an RRA mid-length upper on my SP-1 and really like it so far. I plan on installing the tele-stock but I haven't done it yet. Any chance you can post a pic of yours? Or email it to me?

Sounds like your set-up is exactly where I plan to end up. I have the flat top w/ ARMS #40 as well.

Sorry, not pic capable. Looks sharp though, better than with an a2 stock.