Pillars not touching Action when bedding

[AWLEAPHART]

Guys,
I see rifle stocks bedded with the pillars touching the action but also see some with a thin layer of epoxy over the top of the pillars so that they don't touch. What's the best way touching or not. Also how do you get the pillars just right in the stock with just a thin layer over the top of them with out the pillars touching the stock
Anthony

 

[JRS]

Makes no difference.

 

[BoydAllen]

Years ago, I had the pleasure of a long phone conversation with George Kelbly in which this subject came up. He told me that back in the day when pillars first came on the scene that they (meaning early adopters and experimenters) soon found out that they got better results with at least a thin coat of epoxy between the pillars and the action. We also discussed something that many new shooters may not be aware of, which is pillars cast of something like Devcon aluminum putty, which he verified work perfectly well. I had already read about that option in Precision Shooting magazine, and was aware that the usual procedure was to deal with shrinkage of cast pillars by doing a skim bedding job with a thinner than putty version of whatever product the pillars had been cast with. There is one more thing that I think worth mentioning in this discussion. Short range benchrest rifles, shot over full sets of wind flags, continuously tuned at the range, built in the very most accurate calibers, with specialty scopes, and with the continuous use of a sighter target are able to show small differences in accuracy that would literally be lost in conditions, and would not be possible on a consistent basis with other types of target and hunting rifles. My point is that the difference between skimmed over and metal touching action may not be much of an issue with rifles built for other purposes, and as far as I know, there has been no formal testing of one against the other, so we are left with opinions, rather than test data.

 

[Barrel Nut]

Drill out the stock where the pillars go a bit over sized and use your Dremel tool to gouge out some wood to provide a mechanical bond. Cut your pillars to length so that when fastened to the action, they are just long enough or perhaps a tad longer than necessary (you can trim them later or even bed the bottom metal). Contour the top of the pillars to match the action if you wish or just leave them square. Use special action screws which can be allen head screws with heads smaller than the OD of the pillar or junk screws with the heads turned down and a screw driver slot cut in them. The screws need to have an OD smaller than the OD of the pillars. Wrap the screws with masking tape so they center in the pillar. Wax them up well, but don't contaminate the OD of the pillar. Scuff up the OD of the pillar and torque them down to the action.

Now goober up the stock with Devcon 10110 including the holes where the pillars go. Of course, the normal stock prep applies here. Press the action into place, clean up as necessary, and let cure. Remove the screws. When you pop the action out, your pillars will remain in the stock with the top surface exposed.

 

[JRS]

Here is a great article. No he said-she said. Read all 4 parts: mcmillanusa.com/pillar-bedding-article-part-1. The McMillan's happen to know a bit about the building of stocks, the use of pillars, barrel making, building rifles and scopes

As long as you have stress free full surface bearing, either method will suffice.

 

[jimbires]

what I've seen is when bedded with a thin skim over the pillar the bedding breaks up from being squeezed on . I prefer my pillars to make contact with the action .

 

[Preacher]

I always install them so they touch the pillars......

 

[AWLEAPHART]

Three gunsmiths here near my home touch the action but I just pulled the barrel action out of a stock I think Gregg Tannel did and it has epoxy over the pillars. Top and bottom.
Anthony

 

[Riesel]

You say "Tomato" I say "Tomato"

 

[JRS]

Three gunsmiths here near my home touch the action but I just pulled the barrel action out of a stock I think Gregg Tannel did and it has epoxy over the pillars. Top and bottom.
Anthony

Round, or flat bottom action? With a flat bottom, the pillars are going to be a close mate to the bottom of the action… flat to flat. With a round action, no two actions are going to have exactly the same radius, and would benefit from the bedding compound over the pillars, resulting in full surface bearing.

 

[BoydAllen]

The differences between the two options (as parts of otherwise perfect bedding jobs) may be so slight that for many types of rifles and shooting they are indistinguishable, and therefore unimportant. Just understand that my answer was based on the experience of someone who has been involved in building and shooting competitive short range group rifles in sanctioned matches for decades. His information was about bedding short range benchrest rifles. At 100 and 200 yards they produce the very top level of competition accuracy. Most do not participate in this sport, or build rifles for it. For the majority there may be no difference.

 

[AWLEAPHART]

Thanks for all the info everybody.
Anthony

 

[Rustystud]

I prefer metal(bottom metal) to metal(pillar) to metal(action). The support is there when you torque the screws down, no compressed Wood, fiberglass, epoxy, bondo, etc.

 

[BoydAllen]

Years ago, when Merrill Martin was writing for Precision Shooting and it was being printed in black and white, he wrote an article about a .308 Savage 110 that he was shooting with heavy bullets (lots of torque) for silhouette competition. He had fitted the stock with aluminum pillars that were contoured to the round action and the bedding was done so that the pillars contacted the action. After shooting it that way for some number of rounds, he took the barreled action out of the stock and noticed that there were fret marks on the tops of the pillars, which he took as evidence that there had been some movement of the action on the pillars when the rifle was fired. (Action screws had been torqued to values that were usual for pillar bedding.) Taking a somewhat unconventional approach to the problem he sprinkled some fine silicone carbide powder on the tops of the pillars, reassembled the rifle, and tested the result. With the same load, his groups improved, noticeably.
There were pictures shot both ways included in the article. I believe that the thought behind the SC granules was that it they would key into both the pillars and the round action and prevent movement between them. I read this before my conversation with George Kelbly and for that reason, when I heard of the results that he and his friends had gotten from having some bedding compound over the tops of the pillars, my immediate thought was that it was because it would improve the contact between the action and the tops of the pillars, creating a more stable joint during firing, and because of that, improved accuracy because of more consistent bedding.

 

[Alex Wheeler]

I am firmly in the not touching camp. I want an equal thickness of epoxy surrounding the action. Epoxy shrinks as it cures, aluminum pillars dont. So the epoxy will shrink and pull away from the action. Stress is only one factor in a bedding job.

 

[AWLEAPHART]

Thanks A