Pillar material, SS vs Aluminum ??

[JDJones]

I'm gonna be making some pillars here soon and was origionaly thinking about using either SS or Timanium for the material because I have access to it and figured the extra weight of the SS may be benificial. Well after talking to the smith that barreled my new F-class rig he had mentioned that SS was to hard and it may cause some issues with accuracy. I can see his point on this but I was thinking that if the action was torqued to the pillers and glass bedded fully around them that this should ne be an issue?

My front piller is gonna be very big 1.250" and contured and lapped to fit the action perfectly I will cut it back so that the recoil lug has suffecient cleariance and the rear pillar will be .750", the action will be fully bedded,no mag well) to include 3" of the barrel shank. this is gonna be in a Laminated stock with ADL style bottom

I'm just wondering if I'm screwing up using the stainless steel rather than aluminum.

Any of you guys have any advice or comments on the aluminum vs Stainless steel?

 

[Dans40X]

What action are you using for your F-class rig??
Single shot/ADL configuration-attach a drafted recoil lug to the bottom of the action & do away with the front receiver recoil lug.
If the O/D of your action is not ground,I wouldn't concern yourself about lapping the front pillar radius to the action.
In other words,if the action is turned,machine the radius of the front pillar & epoxy it in the stock.
S/S too hard??
Brass makes some nice pillars also.

If you want some high tech pillars,I'll machine you up some Grd-5 Titanium,material approx $25.00/inch)!!

Whether you use 300/400 series S/S,6000/7000 series Aluminum,
Brass,Titanium make certain that the action screws do not touch the inside of your bushings to isolate vibration/harmonics.

I use .265" diameter "T" shoulder bolts per say to bed/pillar my Barnard & Remington actions for action screw/pillar clearance.

 

[BillK]

Dans40x-Why worry about the bolt touching the pillar? I made mine to just barely have the bolt slip through the pillars and it shoots real well. I have never about the harmonics thing. I would believe that harmonics at this point are to a minimum do to the bolt pulling the action tight and the destructive vibration caused by the wood or fiber glass.

 

[TRECustom]

Bill, after a couple of rifles refused to settle down, I reamed the pillars enough to be sure that the action screws weren't taking any recoil instead of the lug. They stopped scattering hits and some of the loads that were unacceptable got good enough to fine tune. I started making sure that I had clearance in the pillars on all bedding jobs after that. It could be coincidence, but I don't think so. It works for me.

Good hunting, Tom

 

[Dans40X]

The pillar screw hole clearance asures compresion tension not shear tension on the action screws.
The combination has worked for me for the past 20 + yrs on sporter/varmint & match rifles.

 

[clowdis]

On your question about using aluminum or stainless steel for bedding pillars, both will work just fine as long as the 1/4 in. bolts aren't touching. A major caution would be to finish drilling and counterboring the ss pillars before gluing them in. If you don't the heat generated by the counterbore will cause the epoxy to soften and the pillar will spin in the hole. That pretty much trashes the pillar and you have to start over. I haven't had that problem with aluminum pillars because the cutting doesn't create as much heat. You may also want to allow for a washer under the head of the bolts to keep the bolthead from digging into the aluminum pillars over time. It also will allow for more even torquing of the bolts if torque is important to you.
Blair

 

[JDJones]

I have made the pillars from both 316 SS and 7075 aluminum. the action is a Rem Model 7, I have turned the action so that its concentric,took less than .003") and the pillars fit perfectily to the action. I drill the holes with .315" and wrap my screws with tape so they sit center in the pillar and remain the correct center to center distance as the action screws, their is no chance of contact after the recoil lug is bedded. I'm using a wide headed 82deg Torx screw for both front and rear action screws the rear screw will be hiden under the trigger guard, the rear action screw hole was opened up to 1/4-28 like the front..
I'm gonna use the SS pillers that way the front pillar can be polished out nicely and if it doesen't shoot thats what I'll blame it on.

 

[dennisinaz]

I have used 416 stainless for pillars before on a Sako Finnbear action. It is easier when the action is flat on the bottom of course. The benefit that I see with steel pillars is that I can remove the barreled action to travel, drop it back in and snug it down with virtually no POI shift. I have tried it many times and I am within <.5" after putting back together.

With aluminum, I get as much as .75" POI shift. I have found no advantage to using a torque wrench with steel pillars, tight is tight.