Are these wood stocked rifles.
if so is wood compressing over time the problem? Pillars or action bedding should help if that’s the problem.
Too, overly dry storage might be drying the wood causing shrinkage but, I really doubt that’s the problem.

 

They are factory wood stocks with the plastic? pillars. Have a central humidifier and down to 25 percent. The particular rifle today was set at 22 ip. None are more than 25 ip. Two varmints and two MTR's, all in factory stocks.

 

That could be your problem. CZ recommend 3.5 Nm for the actions screws, which is 31 inch-pounds.

Some people test at 27, 29 and 31 inch-pounds but find closer to the CZ recommendation gives a more consistent result.

I'm yet to do the test, but every thing I've looked at would suggest that 25 ip is too light, and possibly may be causing them to come loose.

Edit: source for 31 inch-pounds is also official how-to videos like this one:

 

Put a mark on your screws and take a picture to document where the mark is before shooting. This will show you if they are actually backing out versus loosing clamp load in some other way.

 

Both of my cz’s are wood stocks. I just add a dab of blue loctite and torque to spec. Never comes loose.

 

Red Loctite? My red is for stuff you don't ever want to take apart. Id use my blue that is for periodic disassembly.

 

This is so true. Red would not be what you want to use.

 

This is why you pillar & bed an action…

for this reason right here..

wood expands & contracts no matter the condition-

so does concrete- reason those expansion joints are put in.. if you say mines not cracked- through some water on it, you’ll see the cracks…

putting loctite on action screws does noting but stop up the holes up or push it into the action

 

Anyone ever taste blue loctite ? Not on purpose of course but it’s real sweet. 🤣
I will beat you trolls to it.
SO THATS WHATS WRONG WITH FIREBALL.
HA HA……

 

Let set to air long enough, its worst than fly paper

 

That's why it has a warning to keep away from children (lol)

 

I had the very problem with my AT-1. Installed pillars (Pete's Pillars) and never had that problem again.

 

Thank you for the reminder. I always carry a FAT wrench in my range bag but tbh it rarely makes it out of the bag and on to the bench. It is another habit I need to develop. Can’t hurt. Might help.

 

The only way to correctly re-torque is to loosen the screws a good bit and draw up to the setting in a smooth turn.
Btw, You Don't ever loosen fasteners with a torque wrench.

 

Why don’t you loosen them with a torque wrench?

 

They are not just a wrench but an instrument meant to torque Up Right hand threads. There are special ones for Left hand treads.

 

If a torque wrench is damaged by loosening a bolt, it would not be able to tighten a bolt with left hand thread.

 

The problem: NOTE: NO over torquing - this is how it came from the factory.
(Notice the slight off-center misalignment as well.)

The solution:

 

This how I did mine also.. I bedded over the top of the aluminum when I bedded the action , so the action isn’t touching the naked aluminum.. Bedding shrinks over time. Touching the aluminum will have an affect on the harmonics of the whole system..also went back and drilled the holes 2 sizes up so the screws doesn’t touch the inside of the pillars…

 

Yes, overtorquing can not only damage wood but aluminum pillars as well (some alum is pretty soft).

 

Some have recommended a thread locking compound. Instead, this may be something to consider:
Vibra-TITE VC-3 Threadmate, 30 ml Bottle with Brush Cap Applicator,Red,213

 

If I have threaded fasteners that need to be disassembled fairly regularly but need to be secured otherwise; I generally use Purple Loctite, especially for small threaded fasteners.

 

The color is a quick identifier but the packaging with the application purpose is the real key.
Ive had mine, all Loctite products so no need to go shopping, but Ive heard there are other brands with dif colors

 

After examining the CZ pillars, I've come to the conclusion they are not plastic and appear to be poured. The texture is porous and puts me in mind of liquid steel. When scraping them with a knife edge they didn't feel like plastic.
That changed my decision to repillar the stock, so I simply bedded the action. In doing so it was apparent that the pillars were not perfectly square to the action.
As for aluminum pillars being soft, we've never found that to be true. Maybe there some being manufactured with cheap aluminum but the vast amount that we've used are not soft. Many centerfire rifles that are pillared and bedded are then torqued to 65 in. lbs. At the shop we generally torque to a minimum of 45"lbs. and wouldn't cringe at 65"lbs.
Kimber Montana's are factory torqued to 65"lbs. along with several other manufacturers. I torqued my 2 CZ 457 Americans to 35"lbs. after I bedded them. My groups were almost cut in half and very very consistent.
The top targets are the 457 with a 17HM2 barrel and the second set is the 457 stock 22lr.

 

Somehow I just know heavy torque will be applied where the design or materials wont take it..........

 

If the pillars are good and I'm betting they are, if the pillars are square to the stock, and if the action is sitting on the pillars squarely, then the threads on action screws or in the action will strip before any material gives.
I'm not saying to torque the 457 action screws to 65"lbs., but 35"lbs. is not that much.
If we were talking foot lbs. I would agree, but this is inch lbs.

 

It SO much depends on the % of tread engagement, the material 'screwed into' and the material the screw is made of.
Then there is dry threads vs wet threads, etc.
Folks unfamiliar with the above will read about heavy torque and just do it......
I advise caution

 

The red loctite was a joke..... Also (red face) I might have had the action screws on 21 ip, thought it was 22 so when I checked 22 it moved. But I have had this happen before with CZ 457 ( I have 4). So will continue to monitor and check every cleaning. Bedding might be a solution. I bedded a rifle many years ago that worked fine but not ready to do it again, just yet.