Glass Bedded my CIL Anschutz 180 - Now it shoots goofy.

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fonestar

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So I glass bedded my slightly modified CIL 180. And I think I did what looks like a pretty neat job on it. There's no pillars in it, but the action screws do not touch the stock anywhere. I should mention my rifle is wearing a 2-7x35 Vortex scope and I am not a bad shot.

Here is the weird thing... since bedding it I have shot it with several different types of ammo at 50 yards from a rest. The first three shots will make a neat clover pattern under 1/2". Then the third and fourth shot will shoot around 2" - 3" left of that neat group. Tried many different types of ammo and it's always the same thing.

So far I have tried adjusting the tension on the action screws, putting some electrical tape under the barrel to "un-float" the barrel from the stock, went over everything with a file to make sure there's no sharp edges on the bedding, used a dremmel to make sure the action screw holes are wide and clear of material. None of that made a difference.

One thing I may have done wrong while bedding it was that I torqued the action screws down very tight while I was letting it cure. And I did let it cure for a full 48 hours. Do you think that could cause this? If I need to remove the bedding can I just work around the action screws?

Thanks for any advice!
 
I've shot multiple types from Eley, RWS, Federal Match, etc and they're all the same. The first few shots group very nicely and then the next ones are thrown wide and to the left.
 
don't know the cil 180 , but try skim bedding over the over torqued bedding. tighten just enough to keep it where you want it. no stress. may show an interesting pattern when you separate after curing.I would shoot using the irons, eliminate possible scope & mounting variables.
 
Check for torque in the bedding. Start with both screws snug, around 20 inch pounds. Clamp the barrel in a padded vise with the trigger guard facing up. Now loosen any one of the screws while watching the barrel to stock gap at the fore end tip, there should be no movement. Retighten that screw and repeat with the other. If you get more than about 1/16" of an inch, you have enough torque to mess things up.
 
before you go to town on rebedding etc, make sure the scope holds zero and your mounts are solid. just because it's a vortex doesn't mean you don't have a scope issue.
 
Well I tried Steve's trick by loosening the the front action screw and it definitely raised the barrel more than 1/16". I think I did go back and and touch up the bedding 2 or 3 times so I think maybe different parts cured at different tensions at different times. So I am re-doing the bedding now.
 
PGW Steve said:
Check for torque in the bedding. Start with both screws snug, around 20 inch pounds. Clamp the barrel in a padded vise with the trigger guard facing up. Now loosen any one of the screws while watching the barrel to stock gap at the fore end tip, there should be no movement. Retighten that screw and repeat with the other. If you get more than about 1/16" of an inch, you have enough torque to mess things up.
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Yes, as above. Hold your hand around the barrel and stock as you slacken the tang screw. Feel any barrel movement? Then try same thing with action screw.

You made a mistake by bedding the rifle with tight screws. This bent the action as it set on an uneven surface.

Roughen up the bedding material with rough sandpaper and paint in a this coat of material, and tighten the screw(s) enough to orient the action, but not to bend it down.

next time you bed, leave a little of the original stock material under the screw and for and aft, to keep the action oriented and at the correct height.
 
Ganderite said:
Yes, as above. Hold your hand around the barrel and stock as you slacken the tang screw. Feel any barrel movement? Then try same thing with action screw.

You made a mistake by bedding the rifle with tight screws. This bent the action as it set on an uneven surface.

Roughen up the bedding material with rough sandpaper and paint in a this coat of material, and tighten the screw(s) enough to orient the action, but not to bend it down.

next time you bed, leave a little of the original stock material under the screw and for and aft, to keep the action oriented and at the correct height.
Click to expand...

Yup, little bit of wood in the rear to set the height, and wrap tape around the barrel at the forend to set the height and centre it there too. Helps if you have some screws with cut off heads to get the rotation of it, but the 180 screws are not something one has kicking around. Hold it together with more tape and let it sit undisturbed.
 
fonestar said:
Well I tried Steve's trick by loosening the the front action screw and it definitely raised the barrel more than 1/16". I think I did go back and and touch up the bedding 2 or 3 times so I think maybe different parts cured at different tensions at different times. So I am re-doing the bedding now.
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I was just reading through to see the outcome with the idea in mind that you originally flexed the wood and rifle action by over tightening the screws. So I was nodding my head at your finding that with one screw loose the stock flexes away from the action instead of remaining stable.

The idea of bedding is to achieve a perfect fit with NO bending stresses in the stock or action. By tightening the screws more than what was needed to just barely seat the action and squeeze out the excess bedding goop you included bending stresses in the fit. The whole idea of bedding is to avoid exactly those sort of stresses.

Hopefully your second go works out better. When seating the action and squeezing out the excess compound remember that fingers on the screw driver shaft is just the right amount of torque. Anything more and you risk bending in forces that will stay and defeat the whole point of bedding the action.
 
When I was bedding my CZ 455, I used only enough torque on the action screws to keep the action in contact with two narrow bands of wood that I left (front and rear ) to set the action at the correct height and alignment. The rest of the action channel was ground away to a depth of about 1/8 of an inch.
If memory serves, I used surgical tube to hold the action in place at first, then added the screws once everything was secure, primarily to ensure that everything was in proper alignment. I was concerned that the screws wouldn't thread in if the action was turned slightly as the bedding set up.

My original plan was to revisit the job after the bedding was cured, grind away the two strips of wood, then add more bedding in their place. As it turned out, I haven't done that. The rifle shoots really well, I don't intend to possibly change that by monkeying with it again if I don't have to. There are a couple minor voids that the OCD in me wants to fill in, but the practical side keeps saying, "If it's not broken..."
I did use pillars in mine, the rifle didn't shoot well with pillars alone, though.
 
Given that your two strips of wood are the reference for the bedding job it's no wonder it shoots fine. You'd gain nothing at all by removing those last two strips and filling in with the bedding.

Remember that bedding with resins and such is only an easy way to achieve what can be done with the wood and enough skilled fitting. There's nothing magical about using the resins to do the job more easily and with less wood fitting skills.
 
While you're at it you might as well put some pillars in there. Even cheap lamp ferrules will be good enough. That way you can do it completely stress-free. Tighten the screws up on the pillars and slide the whole thing into the stock and bedding material. That's how I did both my Anschutz 1712 and CZ 453 and I couldn't be more happy with the job.

Edit: Check this. http://www.6mmbr.com/pillarbedding.html
 
_Shorty said:
While you're at it you might as well put some pillars in there. Even cheap lamp ferrules will be good enough. That way you can do it completely stress-free. Tighten the screws up on the pillars and slide the whole thing into the stock and bedding material. That's how I did both my Anschutz 1712 and CZ 453 and I couldn't be more happy with the job.

Edit: Check this. http://www.6mmbr.com/pillarbedding.html
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Good advice. If you're going to bed a stock, you should pillar it, too.
 
BCRider said:
Given that your two strips of wood are the reference for the bedding job it's no wonder it shoots fine. You'd gain nothing at all by removing those last two strips and filling in with the bedding.

Remember that bedding with resins and such is only an easy way to achieve what can be done with the wood and enough skilled fitting. There's nothing magical about using the resins to do the job more easily and with less wood fitting skills.
Click to expand...

Yes and no. By using metal filled epoxies, you try to eliminate as much as possible the difference in expansion and contraction between the wood and action when the temperatures change, in addition to giving the action a better seat to transfer the recoil to the stock.
 
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