CZ 455 bolt coming out of receiver

[lookout]

I purchased this CZ 455 several years ago from the original owner (a friend that had fired less than a box of .22LR shells through it). I changed the barrel to .17 and started shooting it, quickly noticing that when I worked the bolt somewhat vigorously, the bolt came out of the action. Normally, you depress the trigger to remove the bolt. I tried to troubleshoot it but couldn't repair the existing part, so I ordered a new sear from CZ and installed it about 2 years ago.

I've since fired about 1000 rounds in the gopher fields of Sask, and now the same problem is presenting itself. I've tried different adjustments to the nut on the trigger return spring in the hopes that it would rectify the situation. You can see it is tightened as much as adjustment allows. You can also see the pins are properly set (one repair suggested by YouTube). I'm at a loss, and would rather not send this on to Wolverine for repair. Any ideas?

 

[guntech]

That is a problem with rifles that use the trigger for 2 purposes... a trigger and a bolt stop. You can't have a lighter trigger as it needs to be heavier to act as a bolt stop. I don't have an answer for you other than to make a separate bolt stop.

 

[lookout]

I understand the issue with having a light trigger. I'm not even sensitive to having a light trigger so I tensioned it up as much as I could, and still no joy.

 

[guntech]

Some slam their bolts open with great force... some don't.

I have seen screws sheared off on Sako bolt stops... just because of forceful operation on ejection.

Check the corresponding parts that contact the bolt and are failing... are they worn?

 

[Leeper]

The 455 has a problem with this because the design is poorly executed. This strange because the 452 was just fine, but they made a change. There is not enough contact and the geometry is such that there is too much reliance on the trigger spring. I have one in the shop now and will report if my cure works.

 

[lookout]

I really like this rifle and would like to see it repaired - thats why I'm springing for the $ to have it fixed at Wolverine. I'll advise of the results when I know them......

 

[kjohn]

Hmmm... I have 8 455's, mostly .22's, and haven't had that problem - yet. I don't fiddle with the trigger either. They are all as they came from the factory.

 

[lookout]

Leeper, sounds like you hit the nail on the head. Guntech, I work the bolt confidently but certainly not too aggressively. I sent the rifle into Wolverine and received the following response;

"I have had a look at your rifle and found that a couple of the trigger parts have poor mating surfaces causing the bolt to come out. To fix the problem I would need to replace the sear (again), trigger and the 2 retaining pins, bad part is we do not have all parts in stock and would need to be ordered, no ETA for delivery. For $50 more I can install a CZ Flyweight one piece trigger which is fully adjustable and will end any further issues, This trigger is in stock. The total repair, taxes, shipping etc would be $263.28 with the Flyweight trigger."

The repair and my shipping costs bring the repair up to 2/3 of the cost of the rifle when I got it....but I like the rifle so I sprung for the new trigger option. A design flaw to be sure, they were happy to scrap the entire stock trigger and replace it with their upgraded trigger...at my cost of course.

For those with similar problems, just head straight for the flyweight trigger I guess. Thanks for the help boys and girls!