CZ452 Varmint Action Screw

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Andy011

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While I had my CZ452 stripped down and was carving out the stock to fit a new Timney trigger upgrade, I started looking hard at the screw that goes through the stock and into the dovetailed boss on the barrel.

Has anyone here tried relocating this attachment point to the underside of the rear tang?

There is enough there to have the boss welded to the tang and a longer screw going up through the rear hole in the trigger guard to hold it all together. This would truly free float the barrel and still have 2 screws holding the action in place.

Alternatively, has anyone just removed the barrel screw and relied on just the one action screw?

Thanks.
 
I've read on RFC that some CZ shooters have removed the barrel lug and used only the rear action screw without problem. The thinking, I suppose, is that there are plenty of other makes of .22LR rifles with only one action screw that work well. The barrel lug used on some CZ 452 models would seem to be a vestige of their older Brno siblings. CZ 452 Varmints in magnum calibers and magnum Full Stocks use a 452 American receiver which has two action screws.
 
I don’t know if it would work, but sometimes I think putting a varmint barrel on an American action would be a good idea.
 
Andy011 said:
While I had my CZ452 stripped down and was carving out the stock to fit a new Timney trigger upgrade, I started looking hard at the screw that goes through the stock and into the dovetailed boss on the barrel.

Has anyone here tried relocating this attachment point to the underside of the rear tang?

There is enough there to have the boss welded to the tang and a longer screw going up through the rear hole in the trigger guard to hold it all together. This would truly free float the barrel and still have 2 screws holding the action in place.

Alternatively, has anyone just removed the barrel screw and relied on just the one action screw?

Thanks.
Click to expand...

Yes, there was a write up about it on RFC maybe 4 years ago. The gentleman welded the barrel lug to the rear of the action to make it look like 452 American.

The barrel lug screw works fine if you instal a pillar and epoxy bed it in the stock to eliminate any preload between the stock and the barrel. You can retain the lug in the dovetail using a set screw or bond it to the dovetail with good quality epoxy.
Kody
 
Years ago I followed RFC by freezing/seizing the barrel lug using a M6x6 set screw during free floating the barrel.

Just checked and I still have the document and would share with anyone interested enough to send their email address.
 
I have a 452 Classic, I don't share in your pain LOL, for the money you would have saved not buying the timney and getting that trigger kit, or what ever it's called, you could have had the rear tang drilled and tapped and used an action screw up from the rear of the trigger guard like all the cool kids did
 
yodave said:
I have a 452 Classic, I don't share in your pain LOL, for the money you would have saved not buying the timney and getting that trigger kit, or what ever it's called, you could have had the rear tang drilled and tapped and used an action screw up from the rear of the trigger guard like all the cool kids did
Click to expand...

There's no pain here. Just some "what about this?" thinking. The trigger kit doesn't preclude either a welded boss or drill/tap of the tang if I decide to go that road. Is the tang thick enough to drill and tap? I haven't measured it yet, but it didn't look thick enough to get good thread engagement.
 
there is a threaded stud in the back tang that the action screw screws into, however on the 457 action it is drilled and taped. There has been a few guys down south that had the rear tang drilled and tapped with success.
 
Andy011 said:
There's no pain here. Just some "what about this?" thinking. The trigger kit doesn't preclude either a welded boss or drill/tap of the tang if I decide to go that road. Is the tang thick enough to drill and tap? I haven't measured it yet, but it didn't look thick enough to get good thread engagement.
Click to expand...

If you get an ideal action screw length that will engage in the thread to the maximum, but not protrude into the action to interfere with the bolt, you will get about two full revolutions (720 degrees) of thread engagement. I am just going by memory, you might want to do the calc. yourselves. Years ago, I came to the conclusion that it would be enough to withstand 20 in lbs of torque but probably wouldn't be robust to hold up over time. That being said, I never tried it.
2 of my 452s have epoxy bedded barrel lugs and that fixed all barrel lug screw concerns I used to have.
 
yodave said:
there is a threaded stud in the back tang that the action screw screws into, however on the 457 action it is drilled and taped. There has been a few guys down south that had the rear tang drilled and tapped with success.
Click to expand...
Is the 457 rear tang the same thickness as the 452 Varmint?
Thinking of drilling and tapping the rear tang and just run a screw up through the trigger guard, pillar bedded.
 
pretty sure the 452, 455 and 457 are all the same outside diameter and thickness

the 455 is drilled and tapped in the rear tang, the 452 has the floating nut on the back of the action that matches the one up on the barrel
 
EHG said:
Is the 457 rear tang the same thickness as the 452 Varmint?
Thinking of drilling and tapping the rear tang and just run a screw up through the trigger guard, pillar bedded.
Click to expand...

I haven't seen a 457 first hand, but the reports are that several different models are factory pillared. I would surmise that all have pillars. The action screws are located in front of the magazine well and behind the trigger.
 

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yodave said:
pretty sure the 452, 455 and 457 are all the same outside diameter and thickness

the 455 is drilled and tapped in the rear tang, the 452 has the floating nut on the back of the action that matches the one up on the barrel
Click to expand...
Yup.
The action diameter and thickness are the same between the 452 and the 455 except that the 452 action has a deep horizontal slot milled into the bottom of the rear tang in order to accommodate the 452 bolt, making the area about 3 mm thinner than what you get on the 455. This is why they get enough "meat" in the 455 tang for the 455 rear action screw but not enough on the 452. If you Google images for "CZ 452 and CZ 455 action differences" you will notice the change in tang thicknes between both models where the rear action screw is/would be located.
Kody
 
grauhanen said:
I haven't seen a 457 first hand, but the reports are that several different models are factory pillared. I would surmise that all have pillars. The action screws are located in front of the magazine well and behind the trigger.
Click to expand...

The factory 'pillars' is a bit of a stretch. What they did was bore holes into the stock and fill them with what looks to be Devcon. On my 16" MTR you can see the epoxy broke out on either side of the front screw leaving only contact on that 2mm wide strip you can see at the very bottom of your picture. I'm going to redo this properly at some point, but right now my MTR is shooting great.
 
Andy011 said:
There's no pain here...
Click to expand...

On second thought... maybe there is some. The more I think about that barrel screw, the more it bugs me.

I've put a set screw in to lock the boss to the barrel, and we'll see how that works out for me.

Long term though, plan is to get an M6 tapped pad and have it welded to the tang.

Thanks for all the opinions and ideas.
 
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