Home Forums Hunting & Shooting Gunsmithing Best pillars to use?

I’ve reformed. Based on Al’s advice and pictures….. and the advice of other wise members I won’t be torquing action screws any longer. Only base and ring screws…..

I have made pillars from:
3/8" brass tubing.... dissimilar metals problem for the rest of the rifle
3/8" stainless tubing,. dissimilar metals problem for the rest of the rifle
3/8" steel tubing.... my favorite
1/2" Aluminum...... dissimilar metal problem for the Aluminum
I remember 8th grade shop class: https://en.wikipedia.org/wiki/Galvanic_series

I like to glass bed pillars pre compressed. This may require making custom washers for fixturing.
I like to 1.25" diameter side cut the end of the pillar to fit round receivers. 20 years ago, Steve Acker, the gunsmith machinist used boring head to match the pillar end to the receiver radius.
I used to do this, but the end mill is faster and slightly undersized. That lets the receiver spread the pillar ear in compression for better traction for the bullet twist reaction.

I like to rough up the pillar sides so the epoxy can grab the pillar.
I run a tap through the pillar hole in the stock, so the epoxy can grab the stock.

https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/ubb/showflat/Number/14622540

So it's better to just crank them down, then to shoot for a known value
that allows good bolt tension. Or risk too loose/tight?

Trying to understand this. It's not something you do often, you
own a torque wrench, why wouldn't you go for perfect.

If not for bedding purpose, then just for holding?


To be clear here.
My tight ass never bought a suitable torque wrench.
So have always just went with good enough.

True, you can torque for a known value to ensure the screws won’t loosen over time. I was doing it to help ensure accuracy. Not needed with proper bedding.
For scope base: ensures you don’t snap off tiny screws.
For scope rings: avoids ring marks.
For action screws: for a known value.

Al can explain it far better than I can.

I'm not against torquing, per se. I'll circle back to this so bear with me.

The issue with 'torquing' is the preconceived notion that there's some sort of 'magic' torque value(s) that will make a gun 'shoot'. Or worse, that you can 'tune' a gun by changing the torque on the action screws.

The reality is that if either of those approaches show a difference in either accuracy or POI change, you've just demonstrated that the bedding is poor and needs attention.

A well done, stress free (there's the hard part) pillar bedding job will be impervious to action screw torque...given that the torque is at least sufficient enough to keep the action in place and not so excessive as to distort either the pillar, bedding or fastener. All these are basic principles of Hooke's law and Young's modulus, in physics and engineering terms. You can actually see those at work in another post here in the Gunsmithing section where I showed what happened when a guy severely over torqued one of my pillar bedding jobs, requiring me to mill the screw out and modify the bottom metal. Even after all that over torquing, the bedding checked out with no more than .0015 movement...the same as when I'd done it initially several years before. Even then, some don't connect the dots.

Once these are met, if a person wants to or just has to have a reference value, then there's nothing wrong with establishing a reference figure using a good, reliable, repeatable lbs/in. wrench. The import $9.95 ones don't do the job and miss on all the important points, if only obviously.

It's just that at that point (stress free with solid pillars and a quality bedding material), it's just not needed.......

For what it's worth. -Al

So after a time some type of corrosion problem is going to happen between the aluminum pillar and the steel.....

That why I always heard don't put steel screws in an aluminum boat.


Smart feller this Clarkm

For me the use of a torque wrench is a way to prevent over tightening and breaking small screws

The galvanic series referenced involved dissimilar metals in an electrolyte solution (that would be a liquid) and with an electrical current passed through them.

Al I didn't read his link....can you comprehend'e that ?

Galvanic corrosion is slower in the water vapor in the air.

Gotcha.

Makes total sense, and what I assumed.
Just wanted to be sure.

So how did your free pillar bedding job turn out ?

For make your own tubing https://www.speedymetals.com

Now that’s an idea….

These guys are good to deal with, also. -Al

https://www.aluminumspacers.com/

Finally, an update…..
I’ve been working on this for awhile and now have the answer.
Al Nyhus installed pillars are the best. Here are some pictures.
All groups were shot at 100 yards.
The first one is the group the rifle fired with the original sorry trigger and stock with no bedding whatsoever.
The second picture is the group with a Walker trigger that I got from a member here installed.
The third and fourth pictures are the groups with Al’s pillars installed and then bedded by me.
Inexpensive Simmons 6.5x20, with plain cheap imported ammo.
Next steps are hand loads and a new scope.
Looking for scope recommendations….

The rifle is chambered in .308 Winchester.
Many thanks to Al for all his advice and work on the pillars!!!

Glad it worked out...appreciate the feedback. Nice shootin'! -Al

Aluminum is fine but I have done plenty with a piece of left over barrel stub. Nothing wrong with stainless pillars. One thing about a proper Pillar being job is that tight is tight; nothing gives so torqueing to a specific number is not particularly important. My traveling rifles are transported with the stock removed. Simply reinstalling the stock and snugging up put them right back on the original zero. I've proven it many times.

So true, Dennis.

On a well done pillar bedding job, the screws come up to 'tight' instantly. Once they're tight enough to accomplish what their function is, there's nothing else to be gained by further tightening. People fail to realize that if they can change accuracy and/or POI by changing action screw tightness, they've just proven that the bedding needs work.

People buy into the Internet Urban Myths that you can 'tune' your rifle by some mystical, magical method of torquing the the action screws to certain values brought down a mountain on stone tablets or something.....

Unfortunately, the InterWeb makes it easier to believe voodoo and hoodoo than to take the time to get an understanding of what's going on and apply basic mechanical concepts for a solution.

Good shootin' -Al

This^^^^