Eddbo, my R-15 is a 1:9 twist.
rtv900, I'm really enjoying my R-15 so far. My prior 223 AR was a DPMS Bull 20"
Awesome rifle , but a little on the heavy side packing around the hills calling and shooting P-Dogs. That's what I like about the Remington. Very light weight.
I have done zero load work on the R-15 so far, but it shoots the 55gr V-max's I had loaded for my DPMS right at 1" at a 100 yards. I'm sure once the barrel is broke in and with some tweaking of loads, she'll group better.
They are a neat little rifle though. Here's how I set mine up.
3-9 x 36 Swarovski, harris bipod, DPMS two-stage trigger.