04-14-2020, 08:02 PM
redbeard Wrote:Hi folks. I'm a long time Grendel AR shooter but a new forum member. During the fall of 20, I purchased by first bolt action, a CZ 527 MTR. I generally single load from a bench. Shot Hornady 123 AMAX 1/2 MOA or better during break in. After a bit, the bolt failed to close. Sent it back to CZ. They said that single loading, which it wasn't designed for, bent the extractor. Great!! When I got it back, I tried loading from the magazine. I couldn't close the bolt with 5 rounds in the magazine. With 1 or 2 rounds in the magazine, they loaded but was way too hard. I finally discovered the problem after seeing a pile of copper particles between the front of the feed ramp and the chamber. The poorly designed/executed feed ramp had a sharp edge that shaved copper from the bullets. Between the sharp edge and the spring pressure with 5 rounds, still couldn't close the bolt without huge effort. Got a little better with fewer rounds providing less spring pressure. My solution was to use some sear stones and tiny files to round off the sharp edge. CZ should correct the problem. Anyway, I purchased a sled and went back to single loading as approved by CZ.
I should note that I also have the 527 Varmint. Same problem but a little less so.
Strange my CZ varmint grendel doesn't have these issues.
Mag springs were stiff at first and gave feeding issues with 5 rounds in the mag but since they broke in, I haven't had anymore issues.