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CZ LONG ARMS => CZF RIMFIRES => Topic started by: danban on April 05, 2015, 02:28:24 AM

Title: Cz accuracy
Post by: danban on April 05, 2015, 02:28:24 AM
Hi i have a cz 452 In .22 and I'm not that impressed with how it groups. 50 yards and about a 5 cm group. I had it re crowned and scope and mod. What else can cause this?
I have tried lots of ammo.
Title: Re: Cz accuracy
Post by: painter on April 05, 2015, 07:26:07 AM
What grade ammo? Cheapest of the cheap, or some decent stuff?

Also what model 452? Have you checked to see how the action fits in the stock, or played with action/barrel lug screw torques?
Title: Re: Cz accuracy
Post by: viking499 on April 05, 2015, 08:31:03 AM
What grade ammo? Cheapest of the cheap, or some decent stuff?

Also what model 452? Have you checked to see how the action fits in the stock, or played with action/barrel lug screw torques?

Good advice.
Title: Re: Cz accuracy
Post by: danban on April 05, 2015, 12:33:24 PM
It's 452 varmint and used rws Winchester cci.  What are the torque settings for action screwa
Title: Re: Cz accuracy
Post by: painter on April 05, 2015, 01:27:49 PM
It varies. You have to experiment, but it sure sounds like something isn't quite right if the best you can do with that ammo is 2". I'm assuming it was standard velocity, and not HV ammo? Even so you should be able to get better results than that.

Factory torque is reported to be 25 in/lbs. More than that and you'll just crush the wood. Some owners have found the best settings to be as low as 12 in/ lbs. Some rifles respond to both screws being the same and others require different settings.

Is the barrel free floated with the screws tight? Does it change if you loosen the screws? Does the barreled action rock in the stock if you loosen the screws?

Also, is this one wild shot that opens the group, or are they all stray?

I don't think you're going to gain 1 inch by screw torque alone. It sounds like something more basic is off.

Title: Re: Cz accuracy
Post by: danban on April 06, 2015, 03:23:38 AM
It is the full group. The barrel seems free from the stock. When I loosen the screws the action stays flat but it moves left to right barrel end
Title: Re: Cz accuracy
Post by: painter on April 06, 2015, 07:22:54 AM
Moving left to right is typical. Assuming you're shooting off a quality rest to eliminate the shooter from the equation, I think I'd try a different scope, and shoot it without the moderator if that's what you mean by mod in your OP,  before I condemned the rifle. How did this rifle shoot before recrowning?

You might want to have a gunsmith look at the chamber end to make sure there isn't something in the beginning of the rifling causing the issue. It also might be a good idea to slug the barrel to make sure the crown isn't looser than the bore.

If all that turns out OK, and nothing can be found 'wrong', I guess I'd pillar bed the rifle. There's a lot of discussion on RFC as to whether action only, or full length is better. Most 452's shoot better than yours out of the box. Most 455's respond well to full length pillar bedding.

Good luck.
Title: Re: Cz accuracy
Post by: danban on April 07, 2015, 01:28:31 PM
It was a rifle Smith advised me to re crown. He had the action and said nothing wrong.  It's had a new scope and sound moderator
Title: Re: Cz accuracy
Post by: painter on April 07, 2015, 01:43:50 PM
Have you tried removing the moderator, or a different scope?