I have a markII fvxp, same barrel as a tr. It is the most accurate gun ive owned, with just cci standard velocity i get match level results. Its been extremely reliable, no issues at all so far. It was fairly stiff for the first 200 or so rounds, but now i can cycle it very fast. It feeds everything ive thrown at it, from the above mentioned cci to aguila super colibri .. cci cb rounds and aguila 60 grain sniper subsonics. All will feed as fast as you can work the bolt.