How thick do pillars need to be?

vtmarmot

vtmarmot

P Magoon, Livin' Free NH
I am not a "real" gunsmith but I do some stock work on my rifles for both hunting and competition. I understand that pillars are used mostly to prevent compression of the stock material. My question is, what is the justification for making them so big? I often use a piece of good quality aluminum arrow for the rear pillar, roughed up with coarse sandpaper and held in by J-B Weld epoxy. 25 to 30 inch pounds of torque is not going to compress that. For front and middle pillars I use 1/8 wall thickness brass tubing from the plumbing section at Home Depot. I have a nice Dewalt 13/32" titanium bit with starter point that is just right for that. I rough the pillar up and epoxy it the same way as I do the rear. I find smaller holes are a lot easier to drill precisely and less risky. I fit the pillars to the action but leave a tiny bit of clearance to skim bed over them. When I bought my Pheonix I asked Cooper about their pillars and they said they skim-bed over theirs too. Am I missing some unknown benefit of the big pillars?
 
vtmarmot said:
I am not a "real" gunsmith but I do some stock work on my rifles for both hunting and competition. I understand that pillars are used mostly to prevent compression of the stock material. My question is, what is the justification for making them so big? I often use a piece of good quality aluminum arrow for the rear pillar, roughed up with coarse sandpaper and held in by J-B Weld epoxy. 25 to 30 inch pounds of torque is not going to compress that. For front and middle pillars I use 1/8 wall thickness brass tubing from the plumbing section at Home Depot. I have a nice Dewalt 13/32" titanium bit with starter point that is just right for that. I rough the pillar up and epoxy it the same way as I do the rear. I find smaller holes are a lot easier to drill precisely and less risky. I fit the pillars to the action but leave a tiny bit of clearance to skim bed over them. When I bought my Pheonix I asked Cooper about their pillars and they said they skim-bed over theirs too. Am I missing some unknown benefit of the big pillars?
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Well, some of us snug the action-to-stock screws to 65 inch lbs. And the bigger pillars add negligible weight (probably measured in single digit grams), so why not use them, esp. when they're available right off the virtual shelf? Making stuff as you do is great, but if you apply a dollar value to your time in going to the store and fabricating the pillars, you're probably looking at pillars that cost $30 each! :)

Which, by comparison, is what the superb kit from Score Hi would cost you: http://www.scorehi.com/epoxy-pillar.htm#Adjustable pillars

Fabbing your own stuff is great, don't get me wrong. But depending on how long it takes you (like a kid I remember from junior high school who hand-copied the entire contents of a 50-page game manual rather than buying a copy or xeroxing it), the monetary cost is dubious at best.
 
Well, you've got me there, Bill. I guess I just like fiddling with stuff. Also, if I was going to bore a great big hole for those great big pillars, I guess I'd need a better drill press and all instead of using that cheap one that I thought was such a bargain. If I had taken all the money I've spent tweaking guns that will never amount to a hill of beans and bought 5 or 6 real nice ones, I'd be way ahead. Somehow, though that seems to take the fun out of it for me. Also, my shooting would have to live up to all that fancy hardware.
 
The minimum dia. I like pillars to be is .500. With a .312 (5/16) dia. hole and 1/4" action screws, you get .031 of clearance all around the screw and the pillar still have close to .100 wall thickness (.094 to be exact). The thicker wall allows cutting several circumfrential reliefs around the the pillars to hold epoxy. Cutting the pillars .020 under hole diameter and heavily knurling them works really good, too. I have seen a couple instances where thin walled pillars came lose and moved around. On both cases, it looked like there just wasn't enough epoxy thickness between the pillars and the stock material. If thin walled pillars have to be used for whatever reason, knurling them is a must, IMO.

A .500 dia. pillar works well for the rear in the inlet for a standard ADL-style trigger guard. A .562 dia. pillar will fit in the inlet, provided you can dead nuts center the pillar hole. When I order a stock from a custom supplier, I specify .250 pilot holes for the front and rear action screws, then use a .250 pilot on whatever diameter piloted aircraft counterbor the pillars will be and zing the holes for the pillars.

With a .312 center hole in the pillars and a .250 action screw, these flanged 312 o.d./.250 i.d. Delrin sleeves center the guide screws in the pillars when dropping the action into the bedding. The sleeves are epoxied into the pillars from the bottom, then just drilled out after the bedding has set and the action is popped out:

ss.jpg
 
Where do you find those Delrin sleeves? I would like to try that method. I think what has made me nervous about a thick pillar for the rear action screw, is that on some stocks they don't leave much material between the screw-hole and the trigger well. Unless you spring for piloted counterbores, jigs etc. you are looking a a pretty dicey drilling operation. Like I said, I'm not a real gunsmith, so I don't have all the right tools.
 
I found the sleeves at a local Ace Hardware store in the nuts and bolts section...in those little bins that have all sorts of small parts and pieces.

Before I had my counterbores, I used a series of round files to open up the hole. This is better than trying it on a drill press w/o any sort of pilot as the drill press quill will wander side to side and make a real mess of the hole.

The hole in the stock for the front action escheuteon on a 700 is .625, so if you had a .625 and a .562 counterbore (1/8" pilot shank) with 1/4" and 5/16" pilots, you'd be set to go. Of course, you can always leave the escheuteon in the stock and install a pillar hard down on to the escheueon with some epoxy on the mating surfaces, but now you've got essentiall a two piece front pillar. That said, I've done this with no problems on nice hunting stocks where the owners didn't want the appearance changed from original and wished to retain the standard bevel head front action screw.

These guys have reasonably priced counterbores:

http://www.browntool.com/Default.as...1&Level=a&SortField=ProductName,ProductNumber

For about the price of a nice dinner and couple of drinks, you'd be set...............;)

Good shootin'. -Al
 
Pillars that have been installed by McMillan appear to be about 3/8" in outside diameter with a 5/16" center hole. All the pillars do is prevent the bedding from being overcompressed when you tighten the guard screws. I doubt if you're going to get enough pressure on a guard screw to distort McMillan's minimal sized aluminum pillar with normal T-handled allen wrenches or even fold over allen wrenches. When I install pillars they are 5/8" in diameter. No particular reason for that size, just works well with my end mills.
 
Then I feel a degree of vindication, because the brass tubing I use is almost exactly the same dimensions. When roughed up good and installed with plenty of J-B Weld epoxy, they aren't going anywhere. It takes me almost no time to fabricate a pillar to the exact length and contour that I need. I will try the piloted bits, however.
 
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