I've got one.
Used it before I got the anti-chop eye fitted to my Raced-Evo.
Had my cocker running at 16bps using a 12V revvy - could hear the shots where it was "fluffing" - ie pinching the ball - using very brittle two month old RPS advantage shell paint.
Their website is
http://www.apbbolts.com/ and it appears they're doing bolts for other markers too now.
I believe that they're making the APB (anti-pinch bolt) in delrin as well - light (so fast) AND no chops - what more could you want?
(and for all those peoples who reckon the springs cannot keep up with high rates of fire - rubbish. Yes, perhaps the spring will weaken over time, but having used and abused mine, it'll last a long time before that becomes an issue)