Bad pillar bedding diagnostics

[ofdscooby]

I pillar bedded my Mc Millan stock using the score high system. It was shooting amazing now not so much. The other day I was going through my rifle and I noticed when I loosen the front action screw the rifle lowers into the the stock just enough to notice and when I tighten the front screw it lifts out. When i loosen the rear nothing. So I have an issue but have no idea how to figure out where to start to find the problem. Also I ran the same test with the spring and mag box taken out of the hinged bottom metal I'm running. Thoughts?

 

[cahunter805]

Any pics of the bedding job? Did you fit the pillars and check length before bedding? Did you bed the bottom metal?

 

[ofdscooby]

Yes I did set up the pillars to the proper length exactly as per the score hi powepoint. The bottom metal was bedded to the stick as well.

 

[maninthemaze]

Is there bedding compound inside the pillars? Sounds like the screws are threading into the pillars and then threading into the action. This might account for some push on the action before the screw grabs the threads???

 

[FearNoWind]

Front action screw too long?

 

[J E Custom]

Everyone does bedding a little different so this is the way I do bedding because I have very good
results with it.

On most composite stocks, the pillars are not long enough for bedding. (They are supposed to be designed not to need bedding) They do and some changes are necessary to end up with a stress free bedding job.

First I add a bushing to the existing pillars to raise the action enough to give clearance for the bedding compound.

Then I set the barreled action in the stock and float the barrel with the action resting on the extended pillars. once all clearances are suitable, I prepare the stock for bedding (Cleaning all surfaces with lacquer thinner to remove any oils or finger prints. also I ruff up any surface that I can for a better anchor pattern for the bedding compound.

I install headless screws that are long enough to reach through the stock about 1" to aide in there removal. I always use shrink rap on one of the screws to aid in alignment during bedding.

If everything fits well with no binding, I will start adding the bedding compound to the stock.

I consider this a very important part of doing a stress free bedding so I don't use any screws to tighten the action in the stock, Instead I use 3 or 4 spring clamps (They look like jumper cable clamps) to push the action down onto the pillars. these clamps are not strong enough to flex/warp the action and don't add any stress that could be detrimental. after the bedding compound has cured, I carefully remove the headless screws without disturbing the action or bedding.

Wait at least 3 or 4 days to remove the barreled action from the stock (The compound may be hard but it has not reached its full strength until is sets for a couple of days)

After removal of the action, I will clean up all areas that need it and ream the pillars one or two drill sizes larger than they are to prevent the action screw from touching the pillar. (If it touches, it can act like a recoil lug)

When completed and reinstalled the action should be stress free and should not move when tightened down. I normally wait a couple of weeks to do the final torque on the action if I can
to assure myself that I am not compressing the bedding.

Hope this helps its just the way I like to pillar bed.

J E CUSTOM

 

[ofdscooby]

Front action screw too long?

Nope checked that and its good

 

[ofdscooby]

Is there bedding compound inside the pillars? Sounds like the screws are threading into the pillars and then threading into the action. This might account for some push on the action before the screw grabs the threads???

Holes are clean

 

[ofdscooby]

After removal of the action, I will clean up all areas that need it and ream the pillars one or two drill sizes larger than they are to prevent the action screw from touching the pillar. (If it touches, it can act like a recoil lug)

Hope this helps its just the way I like to pillar bed.

J E CUSTOM

I like this and may try this in the future

I thought it may be the bottom metal so I ran the action screws in without any bottom metal and there was still some slight movement

 

[cahunter805]

Did you tape off the recoil lug? Sides? Bottom? Also did you tape the barrel off to help center it and free float?

 

[ofdscooby]

Yes to both

 

[cahunter805]

Any bedding under the chamber area? What did you use to hold the action in the stock while bedding? Screws? Electrical tape? Surgical tubing? I guess I'd be inclined to cut out the bedding around the lug and front of action and rebed it.

 

[cahunter805]

JE
Do you make your own pillars? What do you use for bushing the pillar up?

 

[ofdscooby]

I used score higher adjustable pillars