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-   -   need help! lost accuracy free floating barrel (http://www.firearmstalk.com/forums/f33/need-help-lost-accuracy-free-floating-barrel-4333/)

p5200 05-05-2008 01:42 AM

need help! lost accuracy free floating barrel
 
I free floated the barrel on my CZ 452 Varmint .22 cal. rifle all the way back to the barrel lug but, now can't seem to get as good of groups as I could before? anyone have any ideas what could cause this? and maybe some solutions? Thanks! :(

RL357Mag 05-05-2008 02:31 AM

Maybe too much tension on the lug bolt ? Did you remove material from under the barrel/lug and now you are distorting the barrel when you tighten it?
Maybe try loosening the stock/lug bolt and sliding a shim at various spots under the barrel and test firing - see what happens. You could be getting excessive barrel resonance since a large portion of the barrel is now completely unsupported, although this sounds unlikely in a .22 LR. If it's not an overtightened barrel/stock bolt you may actually need to glass bed. I have an old MArlin 70P (Papoose with detachable barrel) and the entire barrel is unsuported from the muzzle to where it screws into the receiver - it's very accurate as long as I don't rest the barrel on anything while I shoot it.

p5200 05-05-2008 02:43 AM

Quote:

Originally Posted by RL357Mag (Post 23197)
Maybe too much tension on the lug bolt ? Did you remove material from under the barrel/lug and now you are distorting the barrel when you tighten it?
Maybe try loosening the stock/lug bolt and sliding a shim at various spots under the barrel and test firing - see what happens. You could be getting excessive barrel resonance since a large portion of the barrel is now completely unsupported, although this sounds unlikely in a .22 LR. If it's not an overtightened barrel/stock bolt you may actually need to glass bed. I have an old MArlin 70P (Papoose with detachable barrel) and the entire barrel is unsuported from the muzzle to where it screws into the receiver - it's very accurate as long as I don't rest the barrel on anything while I shoot it.

I will check everthing out and play with the bolt torque and barrel shims. Thank for the good advice! :)

Dillinger 05-05-2008 06:55 PM

Quote:

Originally Posted by p5200 (Post 23180)
I free floated the barrel on my CZ 452 Varmint .22 cal. rifle all the way back to the barrel lug but, now can't seem to get as good of groups as I could before? anyone have any ideas what could cause this? and maybe some solutions? Thanks! :(

I would have to agree with RL357 - How you floated it would make a lot of the difference. Can you give us a run down of what you did?

Have you glass bedded the action in addition to the floating?

I assume you didn't do anything like buy different ammo since the floating than you were using prior to the floating. All the components are still the same?

How about the scope, did you by chance remove it for the work and reseat it incorrectly?

Trying to think of the basics here because of the limited information before we get super technical.

JD

npbwbass 06-02-2008 09:51 PM

CZ 452 22 cal.
 
When I restocked mine with paduke wood my CZ 452 had a forward barrel lug about 8 inches in front of the action. The 452 action requires these two mount points and they need to be tensioned equally as not to put pressure on the barrel due the channel being out of alignment either the up and down or left and right axis with the tubular receiver. The forward barrel stud is dovetailed mounted in the barrel. So technically if you free floated the barrel all the way back the action you are missing a critical mounting point for this rifle. I would suspect it doesn't shoot worth a darn.

I over drilled that forward mounting point and bedded it with an epoxy based product called Quick Steel. Then when I mounted the barreled action with the epoxy still unset I was able to get a properly aligned and full stock to stud contact. The original stock was sloppy and the rifle was lucky to shoot 3" at 100yds with Ely Match. It now shoots 3/4" to 1 1/4" all day with about any decent match grade ammo. The CZ 452 while rough looking in some areas of the action is a fine 22 in my book even if it is an slow ole bolt action 22 rimfire.

If this seems all wrong to you then I may have recalled the wrong model of CZ rifle. I am getting older, I will double check mine at home later this evening.

npbwbass 06-03-2008 03:41 AM

yep
 
Its a CZ 452-2E-ZKM. Forward barrel lug is under the rear sight base.

I have got to find my digital camera!!

Dillinger 06-03-2008 03:52 AM

Hey p5200 - We never heard back, did you get it fixed? Are you still battling it? What's the story?

JD

npbwbass 06-04-2008 07:08 PM

Ummmmm..
 
I guess he go it fixed and needed no help, or his computer is broken.

They come and they go.


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