Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Gunsmithing


Reply

Pillar/skim bedding question

 
LinkBack Thread Tools Display Modes
  #8  
Old 02-10-2012, 09:39 PM
Platinum Member
 
Join Date: Jul 2004
Location: Texas
Posts: 5,542
Re: Pillar/skim bedding question

Quote:
Originally Posted by Bart B View Post
Wel, all the epoxy bedding materials I know of expand when hot and contract when cold. Which means it doesn't make any difference if there's a round metal bushing around the stock screws and epoxy of some thickness around the rest of the receiver or no pillars at all. When it's cold, the only hard, bedding points are at the pillars; they don't shrink as much as epoxy. The rest of the receiver's not held as tight on its bottom nor any place else. With conventional epoxy bedding, there's more receiver bottom to bedding contact when it's cold; expecially around the stock screws.

Having shot the same two or three rifles in all sorts of temperatures and humidities from the 20's up to almost 100, they all held the same accuracy level with the same load. No pillar bedding. Just plain old full contact epoxy except for the bottom of the recoil lug which is clear of any epoxy.

Of course one should retorque their stock screws before each shooting situation. ths assures the same compression force at the stock screw areas regardless of the type of bedding.

The most accurate shoulder fired rifles I know of are all conventionally epoxy bedded. No pillars at all.

And don't forget; the receiver expands when hot and contracts when cold; just like pillars.

All different materials have a different coefficient of expansion. but in a properly bedded action
the bedding thickness is minimal and has little or no effect on expansion or contraction.

Most bedding materials are low shrink materials in order to maintain contact with the action
at all times

The main reason for pillars in the bedding system is to keep the action screws from crushing
the stock material to the point of yield and lowering the torque on the action screws.

All stock materials can become compressed over time with the exception of the machined
aluminum stocks. Pillars will expand and contract based on the material used but with
recomended torque loads they will not compress and remain in that condition.

If good pillars and metal to metal to metal contact is achieved re-torquing is rare unless you
remove the action from the stock.

J E CUSTOM
__________________
"PRESS ON"
Reply With Quote
  #9  
Old 02-11-2012, 09:01 AM
Silver Member
 
Join Date: Jul 2010
Posts: 420
Re: Pillar/skim bedding question

With the exception of the angled bottom screw like the M77, the pillars have nothing to do with recoil because that is the recoil lugs job. A pillars only job is to keep the stock from compressing when the bottom screws are tightened.

Soft Material stocks such as wood or the soft non reinforced tupperware brands need them. Hard Stocks like fiberglass, carbon fiber do not need them and can be used the way they are shipped.

Soft material stocks do not skim because the bedding cracks out and they need to have different areas enlarged so the bedding is thick enough not to crack. The hard reinforced fiber stocks all use a resin to hold those fibers together which for all practical purposes if compatible is exactly the same thing that our bedding material is ( they are all Polymers) and if temperature makes a difference to a relatively thin bedding just imagine how much difference is being made to the entire stock I'm pretty sure everyone has a different thought on how to bed and pillar and I cant really say that the differences make any difference at all as long as they have been nicely done and with the right thoughts in place
Reply With Quote
  #10  
Old 02-11-2012, 10:21 AM
Platinum Member
 
Join Date: Dec 2005
Posts: 2,114
Re: Pillar/skim bedding question

Regarding the stock material around the stock screws, one company used a good method to keep virtually the same exact bedding pressure between receiver and its bare wood stock. Anschutz put wave washers between their smallbore match rifle stock screw heads and the stock. This spring loaded the pressure between receiver and stock. Temperature and humidity changes would cause their wood stocks to swell and shrink, but the bedding pressure remained virtually the same.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Pillar/skim bedding question
Thread Thread Starter Forum Replies Last Post
Skim bedding? Hicks Gunsmithing 8 01-24-2011 01:09 AM
A-5 Pillar bed or skim bed B23 Rifles, Bullets, Barrels & Ballistics 3 01-23-2010 11:32 PM
Skim Bedding? scsims Rifles, Bullets, Barrels & Ballistics 4 04-11-2008 08:47 AM
Skim Bedding coues7 Long Range Hunting & Shooting 17 01-18-2007 11:04 PM
Skim bedding an aluminum bedding block. Ankeny General Discussion 19 05-27-2006 10:07 PM


All times are GMT -5. The time now is 07:49 AM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC