Tikka pillar length

[Tac-O]

I am getting a used new factory walnut stock for my Tikka. Even though I pillar and epoxy bedded my laminate Boyd's stock, the stock cracked just behind each action screw hole! I had it at 65inlbs... I guess the pillars didn't do their job. This is a huge bummer. It was a beautiful bedding job and stock!

I have a set of Pete's pillars on hand, but I don't remember what pillar length I'm supposed to have for front and back. Does anyone know the correct length?

 

[MagnumManiac]

Measure the old stock…it ain't gonna change between stocks.

Cheers.

 

[tobnpr]

Picture?
Even without pillars, the bedding job should have prevented "point loads" at the screw locations assuming you had adequate depth of epoxy. Doesn't even make sense to me that it could happen with pillars. Do you have clearance with the screws inside the pillars? There shouldn't be any contact from the screws inside them. Is it a magnum?

You know something was done incorrectly (or it wouldn't have failed)- so natch you need to figure out what it was before doing another stock. Walnut will crack easier than a epoxy-glued laminate.

 

[Tac-O]

Picture?
Even without pillars, the bedding job should have prevented "point loads" at the screw locations assuming you had adequate depth of epoxy. Doesn't even make sense to me that it could happen with pillars. Do you have clearance with the screws inside the pillars? There shouldn't be any contact from the screws inside them. Is it a magnum?

You know something was done incorrectly (or it wouldn't have failed)- so natch you need to figure out what it was before doing another stock. Walnut will crack easier than a epoxy-glued laminate.

It didn't crack from recoil, it definitely just cracked from tightening down the screws. The rear crack is actually just in front of the screw hole. It's visible on the walls of the magazine inlet and there's some type of dark staining of the wood there, like cleaner got there or something. But, I don't know how's that would have happened because I use a good bore guide.

When I bedded it, I had a hiccup that caused the pillars to sit a little lower than I wanted (just below bedding surface), so the action was actually putting more stress on the bedding than it should have.

For the next one, I'll only torque it to 35-45 in/lbs and hopefully won't have the same mistake when bedding the pillars and action

 

[Tac-O]

For anyone curious, I stuck my action into a couple of stocks I have and measured from the bottom inlet surface to the action.

Front is 0.875"
Back is 1.308"

Since the action bosses (if that's what they're called?) are round, the pillar lengths should actually be a touch longer due to where they'll contact the bosses. My barrel is a slightly heavier contour than the factory lite, so I went with that measurement so my action will sit a little lower in the stock. The mag will still load just fine with the states measurements.

Another note, is that since the Tikka stock is pretty slim and the bottom is not parallel to the top, I ground the front (muzzle side) of the bottom of the pillars about 0.010 shorter and that gave me full contact with the bottom metal.

 

[tobnpr]

I always cut pillars about .010 long and bed the bottom metal to them. As long as you're making contact with the pillar/bottom metal in loose assembly it should be fine. If you contact wood and it needs to compress before the bottom metal makes contact with the pillar that's where the problems occur.
If the pillars are correct length, it makes no difference how much torque you put on the action screws (within reason, of course).
You're tightening "metal on metal" and you're placing no stress on the stock or epoxy bedding. Even if you just install pillars and not bed the receiver, all of the torque load from the screws remains on the pillars.

 

[Tac-O]

I always cut pillars about .010 long and bed the bottom metal to them. As long as you're making contact with the pillar/bottom metal in loose assembly it should be fine. If you contact wood and it needs to compress before the bottom metal makes contact with the pillar that's where the problems occur.
If the pillars are correct length, it makes no difference how much torque you put on the action screws (within reason, of course).
You're tightening "metal on metal" and you're placing no stress on the stock or epoxy bedding. Even if you just install pillars and not bed the receiver, all of the torque load from the screws remains on the pillars.

Yes, that's my goal! I'm going to remove plenty of wood from the action inlet to make sure that the action will rest on the pillars when I put bedding compound in. I'm just trying to decide if I want to do pillars first and then the action bedding, or if I want to try to do it in a single process. It didn't work so well for me last time I when I did it in one process

 

[tobnpr]

This might help...

You are being redirected...

I've done it both ways, and it's obviously a time-saver to do the pillars at the same time as the receiver bedding.
But as you said, setting pillars first gives you the opportunity to "confirm" clearances. Set the pillars (I use JB Kwik as it's fast setting), then place the action into the stock. I then confirm clearance all the way around the receiver sliding a piece of thin cardboard all around the sides and bottom of the stripped action. Should be free & clear all around except where it's sitting on the two pillars.

When you do all at the same setup, you need to leave original material at the back of the tang to set the elevation, and tape wrap the barrel to both center, and establish elevation of the front of the receiver. When the pillars are pre-set, you need to relieve the entire tang area so that the action rests only on the pillar- and not the stock.

 

[Tac-O]

This might help...

You are being redirected...

I've done it both ways, and it's obviously a time-saver to do the pillars at the same time as the receiver bedding.
But as you said, setting pillars first gives you the opportunity to "confirm" clearances. Set the pillars (I use JB Kwik as it's fast setting), then place the action into the stock. I then confirm clearance all the way around the receiver sliding a piece of thin cardboard all around the sides and bottom of the stripped action. Should be free & clear all around except where it's sitting on the two pillars.

When you do all at the same setup, you need to leave original material at the back of the tang to set the elevation, and tape wrap the barrel to both center, and establish elevation of the front of the receiver. When the pillars are pre-set, you need to relieve the entire tang area so that the action rests only on the pillar- and not the stock.

Agreed! That's a great article. I've read it multiple times before.

I like the route of putting pillars in first so that I know they'll sit on the bottom metal, but then when I go to bed the action, I don't know how I would get the action sitting directly on the pillars without any compound in between.

Going the route of attaching them to the action and bedding all at once, I wouldn't be able to verify they would rest on the bottom metal.

An alternative I've been thinking about is to attach the pillars to the action with the screws. Paint in some compound around the crevices between the pillar and action and clean up the sides of the pillars and excess from the action that is outside of the pillar area. Let it cure. Remove the screws. Now the pillars are attached and in direct contact with the action. Put the bottom metal into the stock and then remove enough wood from the action inlet so that the action only touches the pillars, which are resting on the bottom metal. Remove the action and put long headless action screws in. Then put the compound into the stock and set the action into the stock which has the pillars and "guide" screws attached to make sure you're aligned. But, I'm not sure how to prevent getting compound between the pillars and bottom metal doing it that way haha

 

[Tac-O]

I got the stock bedded last night. I drilled the holes for the pillars (oh man I need to get a drill press ) and dryfit the action into the stock with pillars attached prior to removing any wood. The pillars were dang near perfect length and would contact the bottom metal nicely if using the inlet surface as reference height.

So I decided to bed the whole thing at once with pillars. I removed wood from the inletting except for right behind the range to use as height reference and used the tape wrapped on barrel as the front height reference. It went really well except I pushed down on the front a little too hard and so the front pillar protudes maybe 1/32" out from the bottom metal inlet. I should be able to just sand that flush though since they're aluminum pillars.

I used electrical tape to secure the action, which I've done before and it works well.

I'll get to break it out either tonight or tomorrow morning.

 

[tobnpr]

I drilled the holes for the pillars (oh man I need to get a drill press

What did you use to open up the action screw holes?
Just taking a drill bit to them with a hand drill isn't going to prevent the bit from wandering, even though it will tend to follow the original hole.
A "piloted counterbore" is best used for this- and it works just as well with a hand drill. The pilot will follow the original hole perfectly, and the larger counterbore behind it opens up the hole. Some can be pretty pricey, but a cheap Chicom one will work just fine on wood/fiberglass.

Good luck with it.

 

[Old Rooster]

I have used adjustable pillars and they have worked great.I set them to my desired height and glue the top so I can adjust the bottom part of the pillar.I made a steel templet to set the top just a bit above the stock on both front and rear.
When I get what for the bottom adjustable part of Pillars I glue from the bottom so the adjustable part is non-movable.Levels everywhere so all is straight.
Before I pour bedding compound and the pillars are glued in I sit my action on the pillars and tighten the action screws a little at a time and with a dial indicator I check for stock stress.If one Pillar is higher than the other it will cause stock stress.Stock stress can cause stock cracking and poor accuracy because it has the action in a bind.
Just some of the things I do when Pillar bedding a stock,wood or synthetic

 

[Tac-O]

I have used adjustable pillars and they have worked great.I set them to my desired height and glue the top so I can adjust the bottom part of the pillar.I made a steel templet to set the top just a bit above the stock on both front and rear.
When I get what for the bottom adjustable part of Pillars I glue from the bottom so the adjustable part is non-movable.Levels everywhere so all is straight.
Before I pour bedding compound and the pillars are glued in I sit my action on the pillars and tighten the action screws a little at a time and with a dial indicator I check for stock stress.If one Pillar is higher than the other it will cause stock stress.Stock stress can cause stock cracking and poor accuracy because it has the action in a bind.
Just some of the things I do when Pillar bedding a stock,wood or synthetic

Do you have the dial indicator touching the barrel and forearm? I did this once by connecting one to the barrel and had the indicator touch the forearm near the end.

 

[Tac-O]

What did you use to open up the action screw holes?
Just taking a drill bit to them with a hand drill isn't going to prevent the bit from wandering, even though it will tend to follow the original hole.
A "piloted counterbore" is best used for this- and it works just as well with a hand drill. The pilot will follow the original hole perfectly, and the larger counterbore behind it opens up the hole. Some can be pretty pricey, but a cheap Chicom one will work just fine on wood/fiberglass.

Good luck with it.

I used a step bit. It works really well to get the correct hole size started while keeping everything centered, but a 1/2" bit is way to big to be able to drill a hole with a hand drill without tearing extra wood out.

I think it will work out just fine!