McMillan/synthetic or re-bedding CZ 550?

[Questor]

I've got a CZ 550 that needs to be re-zeroed every time the humidity changes a little. Will having it glass-bedded solve this problem, or do I need to go to a synthetic stock? Have you had any luck solving this problem?

[dave375hh]

Glass bedding will stablize it as long as you make the bedding thick enough(say 1/4") and isolate the metal from the wood. Glass the action and float the bbl. I like to see at least a std. buisness card slide between the bbl and forend. Even a synthetic stock should be glassed with a skim coat.

[gwindrider1]

Questor,

I solved this problem with my own CZ 550 with my usual method of bedding the barrel channel.  Before bedding the channel, I use the dreaded Dremel tool to route out a square bottomed groove the full length of said barrel channel, stopping about an inch and one half shy of the forend tip.  I make this groove 1/2" wide, by 1/2" deep.  This is filled with bedding compound containing a high percentage of glass fibers.  This, essentially forms a rigid beam in the bottom of the channel, which is highly resistant to warping.

Another trick is to use a carbon arrow shaft, filled with bedding compound, bedded into the routed out groove.  If you can stiffen the barrel channel suficiently, you will not have the POI shifts you are experiencing now.  Best of luck with that 550. 

[BUSTER51]

That carbon arrow shaft trick sounds like a winner ,can't wait to try it on the next stock I bed .