I got a pack of O rings yesterday.
My observations are (just from installation, haven's shot either gun yet) is that the P01 has plenty of barrel between the thread protector and the end of the slide to clear the O ring. I used the 7/16 X 5/16 X 1/8 O ring with no problems (it does look a little funny as it bulges out slightly larger in diameter than the thread protector.
On the CZ 85 with the threaded barrel there is so little clearance between the thread protector and the slide that the gun can't lock up with the slide fully forward. I got a 7/16 X 5/16 X 1/16 O ring and even though it is almost invisible with the thread protector screwed on it also keeps the slide from locking up unless you just let the slide fly forward under full spring pressure/velocity. While that might be okay at the range I'm not sure I'd trust it for anything serious. I can't say if/or when the gun might fail to lock up as it got dirty or a somewhat lighter load was used (could be fine, it just isn't right/normal).
And wouldn't you know it. While I was messing with the P01 I noticed the front sight was "dead". It worked this weekend. I remember seeing the glow Sunday night when I walked into the bedroom (it was lying just under the bed in the spare bedroom we were staying in at my mom's house). We drove back down here Monday afternoon with the P01 in my AMIII under my arm and I put it back in it's hiding spot in the living room until last night when I was messing with the O rings.
I'm assuming the tritium gas leaked out for some reason. With no drops and no knocks I'm not sure how it could have just leaked out of the tube. Now to contact CZ USA and see what they can do for me. I sure hate to ship the whole pistol, or even the slide, off to have the sight replaced, if they've even gotten any of the suppressor front sights in stock yet. I wonder if they'd just ship me the sight and let me return the defective on to them? We'll see.
