I have the CZ 527 in 7.62x39. Nice quick handling rifle. The drawback that I have experienced was that you cannot single feed a round into the chamber unless it is loaded from the mag. The problem I had was if I tried to single feed a round the extractor claw would not 'cam over" the rim of the cartridge. When you tried to pull the bolt back the claw disengaged from the extractor collar causing much frustration and expletive laden sentences. You could not disengage the bolt from the rifle. You had to "pinch" the extractor collar together while pushing the bolt and extractor forward to engage the collar "clips". Pain in the butt!
I questioned CZ USA about this and was told not to single load and to use the mag only. I don't know if this was a design flaw or something I did.
The other issue I had was that it would not shoot military ammo. I had some old ammo kicking around that I had fired from various AK'S years ago. I was not able to shoot the military ammo in the CZ unfortunately as the firing pin would only "touch" the primer (I was told that I could bevel the firing pin hole on the inside of the bolt or adjust the pin to hit it harder but as I reload didn't really need to).
If you decide to take apart your rifle for what ever reason pay attention when trying to put it back together. The mag well, mag release and receiver have to line up perfectly and I mean perfectly in order for everyone to maintain happiness.
What I don't like about CZ rifles is the type of bluing used. It seems to get a film of rust fairly quickly, and yes I apply a thin coating of oil as per usual protection requirements. Any of the other rifles I have from various manufacturers this doesn't happen.
What I did find was that the chamber seemed to be really tight. I was trimming the case as per Hornady spec's (1.518") but a number of rounds would not chamber when closing the bolt. I just happened to pick up the LEE Modern Reloading manual #2. It lists the case trim length as 1.516" which solved the problem.
It's a great little deer gun out to 175yds or so. My CZ shot under MOA using Hornady 123gr SST's. Best load for me was 26.6gr's of RL 17 using CCI 200 primers and Lapua cases. Avg velocity of the string set was 2316fps. Grouping was 0.35"
If you have trouble getting RL17, IMR 4198 works too. I used 23.7gr's IMR 4198, CCI 200 primers, Lapua cases. Ave 3 string set was 2225fps. Grouping was 1"
I picked up a box of factory PRVI 123gr & 150gr RNSP just see how they performed. Accuracy was avg (around 2" at 100yds) but the velocity was really moving at 2513fps for the 123gr and 2195fps for the 150gr!
***UPDATE*** Thanks to the eagle eyed Zedbra I made a typo when listing the Alliant powder I used. Got a little to "copy & paste" happy. Should be RL7 not RL17. IMR 4198 is correct. ALWAYS VERIFY INFORMATION GIVEN.