nextjoe
Member
I wrote this for another forum I frequent, but I want to post it here and see if anyone else has encountered this situation.
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I did some investigating into the problem D Hunter reported, regarding his CZ 550 sometimes failing to cock. I examined one of my own CZs and found I could recreate this problem. Here are two pictures illustrating the problem, along with an explanation. First, the way it should be:
This photo illustrates the way the sear should return to position after lifting the bolt handle. It springs all the way back up and clears the trigger. Now here's the problem:
This shows the sear hung up on the rear of the trigger and therefore not resetting to its proper position. Compare the area in the red circle to the picture above.
Note that in both pictures the bolt is open and partially retracted. As soon as the cocking piece clears the sear, the sear SHOULD spring back up into place (reset). The malfunction occurs when the sear gets stuck on the back of the trigger and doesn't reset. When this happens, the sear isn't in place to catch the cocking piece as the bolt closes. The result is an uncocked rifle with the firing pin resting on the primer of the chambered round. Not good.
D Hunter reported that this happened more often if he short stroked the bolt of his rifle. On my rifle, I found the problem only occurs if the bolt is lifted very gently and smoothly. To me, this indicates that the jolt of opening the bolt briskly or bringing it back against the bolt stop smartly is enough to jar the sear loose so that it resets properly.
How do we fix it? My guess is that two things need to be done. First, a stronger sear spring will help to assure that the sear resets properly. Second, the back of the trigger and front of the sear should probably be polished a bit more to reduce friction and decrease the chances of these surfaces sticking.
I don't know the history of D Hunter's rifle, but mine is completely unaltered and exactly as it came from CZ. No attempt has been made to adjust the trigger or otherwise change any part of the rifle.
I'll be contacting CZ-USA regarding this problem ASAP and reporting back to the group regarding their response. In the meantime, if any forum members could check their guns for this problem and report back, it would help establish how widespread this condition might be. Phil Shoemaker reported having the same problem with his CZ in "Rifle's Hunting Annual" number 6, fall 2002.
Thank you.
Best,
Joe
-----
I did some investigating into the problem D Hunter reported, regarding his CZ 550 sometimes failing to cock. I examined one of my own CZs and found I could recreate this problem. Here are two pictures illustrating the problem, along with an explanation. First, the way it should be:
This photo illustrates the way the sear should return to position after lifting the bolt handle. It springs all the way back up and clears the trigger. Now here's the problem:
This shows the sear hung up on the rear of the trigger and therefore not resetting to its proper position. Compare the area in the red circle to the picture above.
Note that in both pictures the bolt is open and partially retracted. As soon as the cocking piece clears the sear, the sear SHOULD spring back up into place (reset). The malfunction occurs when the sear gets stuck on the back of the trigger and doesn't reset. When this happens, the sear isn't in place to catch the cocking piece as the bolt closes. The result is an uncocked rifle with the firing pin resting on the primer of the chambered round. Not good.
D Hunter reported that this happened more often if he short stroked the bolt of his rifle. On my rifle, I found the problem only occurs if the bolt is lifted very gently and smoothly. To me, this indicates that the jolt of opening the bolt briskly or bringing it back against the bolt stop smartly is enough to jar the sear loose so that it resets properly.
How do we fix it? My guess is that two things need to be done. First, a stronger sear spring will help to assure that the sear resets properly. Second, the back of the trigger and front of the sear should probably be polished a bit more to reduce friction and decrease the chances of these surfaces sticking.
I don't know the history of D Hunter's rifle, but mine is completely unaltered and exactly as it came from CZ. No attempt has been made to adjust the trigger or otherwise change any part of the rifle.
I'll be contacting CZ-USA regarding this problem ASAP and reporting back to the group regarding their response. In the meantime, if any forum members could check their guns for this problem and report back, it would help establish how widespread this condition might be. Phil Shoemaker reported having the same problem with his CZ in "Rifle's Hunting Annual" number 6, fall 2002.
Thank you.
Best,
Joe
