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davem
March 17, 2012, 11:06 AM
HELP- years ago there was glass bedding- you often free floated the barrel and just did the bedding around the action. THEN I started reading about pillar bedding and I am confused. It seems that some folks just put in the pillars and bed around them and maybe the recoil lug area and that's it- no other glass bedding. IS THAT CORRECT? I thought you had to do both. My problem is if you pillar bed first then how can you later glass bed or if you glass bed first and then pillar bed won't that effect the glass bed.
Do you pillar bed AND free float the barrel or leave the barrel channel alone?
In any event the object is improved accuracy. Is the pillar bedding normally all you do? Thanks.:cool:

Goatwhiskers
March 17, 2012, 01:33 PM
The two methods are just different ways to attempt to support the action in a consistent way to improve accuracy. I've been doing this stuff over 40 years, either alone when correctly done will do the job, nothing magical about either, put 'em together if you want to. Ya pays yer money and takes yer choice. Goatwhiskers

brickeyee
March 17, 2012, 01:41 PM
Pillar bedding is another method to try and isolate the action from the stock.

Wood changes shape and size with moisture content changes, and no finish can effectively stop the movement of water vapor in and out of wood.

Some of the 'epoxy' type finishes can come close, but most are not thick enough or applied uniformly enough to stop all movement of water vapor.

Localized movement can be worse than uniform movement

If the material of a non-wood stock is affected by moisture content it can also move.

Any movement can produce changes in loads on the action and effect its behavior under the stress of firing.

Wood touching a barrel is well known to alter the vibration patterns in the barrel.
Wood exerting force on the action may change its vibration patterns.

hooligan1
March 17, 2012, 02:34 PM
And really, depending on the action of your rifle model, and if your handy with hand tools and such, you can do the pillar bed yourself.;)

mete
March 20, 2012, 06:38 AM
If you do a "complete" glass bedding of the action including around the action screws you don't need the pillars.I did that on a cpouple of my guns and they've never moved in 40 years !! I also bed 2" of barrel with the rest free floating.

brickeyee
March 20, 2012, 09:42 AM
If you do a "complete" glass bedding of the action including around the action screws you don't need the pillars.

So you think the glass bedding is going to stop the stock from changing shape and size with moisture content and putting pressure on the action?

tim s
March 20, 2012, 09:46 AM
A good pillar bed is used in conjunction with a good glass bedding job. No matter how good a glass bed job, a wood stock expands and contracts and proper pillars minimize the impact of this. Pretty simple concept.

mete
March 20, 2012, 07:07 PM
Brickeyee, I have two rifles which I made up in gunsmithing school 40 years ago .I can take the stock off , replace it and the first shot is at the same point of impact as before removing !!! The rifles were made up in semi-arid CO , now in sometimes humid NY ! No problem. Remember that there are lots of variables.Forend and everywhere you can't see ! must be sealed either with polyurethane or light coating of glass/resin .Barrel free floating .Fairly thick glass around receiver ,down around receiver screws ,around trigger opening. The glass is for strength not just a sealer around the receiver.
BTW for rifles in general don't be afraid to be generous in free floating the barrel. While a business card [.004" ] may be OK for an arid climate taking that gun into a humid area requires a generous .040" for movement unless re-inforced.

brickeyee
March 21, 2012, 09:01 AM
You go lucky.

Even glass bedding it not going to stop all the movement of a piece of wood.

Look here for a very detailed explanation of wood movement:
http://www.woodweb.com/Resources/wood_eng_handbook/Ch03.pdf

Figure 3-3 is especially revealing.

old roper
March 22, 2012, 07:02 AM
Gunsmith have been doing one form or another for pillar bedding for years. I've had it done were they fill the guard screw holes with bedding then drill it out for the action screws and they used to have some screws that were smooth and you bedded around them.

I have all my rifles bedded most have pillars barrels are free floated but are bedded under chamber area.

mete
March 22, 2012, 05:47 PM
BTW one of the things they do to reinforce the forend is to mill a channel the length of the forend and fill it with glass/resin .

davem
March 23, 2012, 12:49 PM
Well I guess I'm not getting my question answered- on the net there are some sites that show how to pillar bed and that looks like that is the end of the job- there is a little glass bedding around the pillars. The type of glass bedding I'm familiar with usually includes the whole action area of the stock.
Should I first put in the pillars and let them set and THEN remove any high wood from the other areas of the action area and then glass bed those areas? It would seem first putting in the pillars is logical because then you could screw the barrel down on the plliars and the rest of the action area would then conform to the bedding job. In other words- how do you go about it. OR..... is the pillars enough and you should forget about bedding any other area of the stock?
Thanks again for any help.

pdogkilr
March 23, 2012, 02:52 PM
I have done one bedding job. Still have the rifle. It is a Winchester Model 70 in 300 WinMag. Three to four inch shooter before, 3/4 to 1 inch shooter now.

In answer to your question, I did a pillar bed in conjunction with an action bed "at the same time". I bought some items from Brownell's:

Pilot Drill Bit - designed specifically for pillar bedding (makes the hole straight in line with the existing screw holes.

Action Bedding Screws - longer with "T" handles for pulling the action into the bedding.

The Pillars - I went with aluminum.

Brownell's "Steel Bed" - their claim is that this epoxy compound comes with a quarter pound of powdered stainless steel (looked like it to me). They say once set, it can be milled on a lathe. I don't know about those claims, but it worked great for me.

I hogged out the recoil lug area and around the action - also for two inches ahead of the barrel, then re-drilled the two action screw holes. I put two layers of painters tape on the front and sides of the recoil lug, and two layers ahead of it on the barrel. I also used painters tape along the top edges of the stock. Painted the metal with release agent, rolled the pillars in the mixed "steel" epoxy (to get epoxy in the pillar's grooves) and inserted them. Thinking back, I believe I used a Q-Tip to coat the inside of the pillars with release agent. Then used a wooden stick (tongue depressor) to fill in the hogged out areas of the stock and recoil lug slot, and put the wood and metal together. Used the T-handle action screws to pull the action down snug and let it sit for a couple of days. Didn't need to wait that long, just had other stuff to do. I loosened the T-handles a few turns then rapped them with a plastic mallet. The action popped free and I cleaned it up then reassembled everything. The bedding looks like a single piece, including the pillars. Went to the range and was really pleased.

So, yes - there is epoxy around the pillars. I strongly suggest using the Pilot Drill bit. It opens the action screw holes enough for the pillars and epoxy. Brownell's is a great source for stuff like this.

Hope this helped.

davem
March 25, 2012, 03:39 PM
Thanks pdogkilr- that's exactly the information I needed. Because I'm a little slow, I'll repeat what I think I should do.
1. Get a pilot drill and redrill existing action holes to accomodate the pillars.
MY THOUGHT_ if pillars are oversized- file to correct length???
2. Remove wood in the action area for the glass bedding material.
3. Put tape over the FRONT and SIDES of the action lug- the idea to create a little space in the front and sides.
4. Tape the barrel in front of the action- sort of free float barrel???
5. Tape over stock's outside to protect it.
6. Wax- release compound on action / barrel and molding clay in any nooks and crannies that could create a mechanical lock.
7. Mix up the epoxy- first roll the pillars in epoxy and install in their holes, then put putty in stock area.
8. Clamp/screw down action to stock- wait a day, ramp to free.
Is That the correct process? Thanks again.

Clark
March 26, 2012, 01:36 AM
brickeyee


Even glass bedding it not going to stop all the movement of a piece of wood.

Look here for a very detailed explanation of wood movement:
http://www.woodweb.com/Resources/woo...dbook/Ch03.pdf

Figure 3-3 is especially revealing.

20 years ago I would hand out copies of Hoadley's "Understanding Wood" which has much of the same information.

http://www.amazon.com/Understanding-Wood-Craftsmans-Guide-Technology/dp/1561583588

I like to say that we glass bed and pillar bed to get the stock to be low compliance coupled to the barreled action so that the stock mass becomes a consistent part of the recoil reaction before bullet escapement.

But i don't think most people glassing and pillar bedding understand all that is required for that, they just perform a ritual.