I converted my DRS Classic into a tactical format with Buck Rail's BR modular chassis. I have the 700mm SHP in .22 and I mostly shoot 33g H&N precision slugs at 934 FPS. The are ragged hole at 30 yards (my zero distance) and are covered by a dime at 50 yards and under 1 MOA at 100 yards (depending on wind). I have my pressure set to 148-150 bar (as best as I can read the gauge). I have a Huma Mod40 on it and it is about my quietest .22 especially for the speed. But it is really long and tuff to woods walk with it. So I use it on a tripod when I go and "sit and hunt". The AR kit shaved weight off an already light gun.
I also have shot 21g GQA .217 LDC cup based and 22g AVS .218 dish base both at around 1040fps. Not as accurate as they H&Ns for target work but great for hunting.