CZ 455 Varmint, eh?
lemme see here, where to begin?
Let's look at the stock, first, not a lot of wood left to provide stability.
All that open inletting doesn't help accuracy
Nope, not a good thing having the action screw holes open to the rest of the inletting
Solution: bed and pillar the receiver
That'll solve a bit of the problem, also prevents your bottom metal from kinking
due to uneven loading caused by the lack of support from the open sided screw holes.
Check those action screws too. Mine were barely making it into the receiver.
Only a couple threads worth of bite, not really something I was happy with.
Trip to the hardware store for some 6mm-1-30mm and 6mm-1-35mm flat head cup screws
A little work with a file and some test fitting resulted in screws that
ended up just under flush with the inside of the receiver, all threads biting
Front and rear
Then you play with torque settings.
My 455 Varmint likes the barrel screws at 30 inch-lbs
and the action screws at 28 inch-lbs. Without the longer screws
those torque loads might have stripped threads from the receiver.
After finding the best torque values, then you might try barrel shimming.
The Varmint and American stocks have nice lines, but at a cost.
So much wood has been removed to get those lines and open the inletting
that the stocks have lost rigidity and flex under recoil loads. Even from 22lr recoil loads.
I tested shims the entire length of the forestock
Best results came from this epoxy bedding/shims
There are those who swear free floated barrels are the only way to obtain accuracy.
Thorough testing has proven to me otherwise. I've tested 4 different CZ 455's and all
had better accuracy with shimmed forestocks. Probably as the combined structure
of barrel and stock make for a more rigid unit and prevent stock flex.
I don't rely on my shooting abilities to test modifications.
I use a test rest so my lack of skill won't affect results.
Takes shooting about 2 bricks worth of ammo to polish the rifling/bore
before the true accuracy of the barrel can be determined.
Best accuracy will come from expensive sub-sonic match grade ammo.
For field carry, the factory trigger works fine.
For bench use, an aftermarket adjustable trigger is needed.