pillar length, how to measure?

I'm ready to install pillars in my new wood stock. I got the much suggested lamp rod for pillars and now see why they're about perfect. What I don't know is how to measure to get them the right length. I'm assuming that I should make them a tad long and just keep filing and test fitting, but I don't know when to stop.
How do I determine when they're the correct length?
Thanks for any help.

They need to be long enough so that there is only metal to metal contact from the head of the action screw to the pillar, and on the other end, the pillar against the action.

I would cut or file them to length, test fit, and then bed the action and pillars as one unit. I would make sure the ends are flat and perpendicular to the length. I would not curve the end that rests against the action.

Ideally, the bottom of the pillars are recessed, so as long as the action screwhead does not protrude below the bottom of the stock you should be ok on length.

http://www.6mmbr.com/pillarbedding.html
The above link is the way I have done it, realizing that that article was written for a Savage and some things are slightly different with your rifle than with the author's rifle.

Thomae nailed it. They can be any length you want them to be, as long as they are long enough / short enough to allow the action screws to hold the action tight against the pillar.

The rear pillar is pretty much a set length. To long and either the action sits up or the trigger guard isn't flush.

I cut mine a tad bit long and test fit them with the screws to where when torqued the screw was flush in the inside of the action...maybe a thousand or so less.

I bed the action and pillars as one unit like thomae suggested.

Thirty06 is correct in that the support of bottom metal regardless of the front or rear is important. some may argue that the support of the adheasive to the stock is sufficient regardless of the bottom metals contact with the pillar. I'm cool with that but for me after I drill out my screw holes I fit the bottom metal and drop the pillars in until they are the correct height on the action side. I have used clay as "plasti-gage" to make sure there is no gap by screwing it all together. I am interested in how many others support the bottom metal with their pillars.

With the trigger guard being the only bottom metal of non-removable magazine Savages I just bed it separately after the pillars are done.

Stang, I support the bottom metal with the pillars, as you say.

When starting, I cut them long, assemble everything, then test the action. File them down and test again. All the while trying to keep the action level to the stock. Sometimes I get one or both too short, and so I start over, cutting it a little long from where I left off.

Thomae's article is a good one. I think Savages are a little tougher because the rear pillar needs to be trimmed and positioned just right to allow clearance for the sear. Once I'm satisfied with their length, I "tack" the rear pillar in place with a dab of bedding material and assemble everything, using the action screws to draw everything in tight. Once that dries, I disassemble, test it again. Make adjustments as necessary. If all is good, then bed it all.

Thanks for all the replies.
I've made both pillars now and I have metal to metal contact on both ends. I did screw up and make the front pillar too short after filing it for a good square fit as Thomae suggested. No biggie, just started over. I notched the rear pillar and sear works perfectly. The top of the pillars are maybe a few thousandths taller than the wood, same for the bottom. I'm getting solid metal to metal on both ends and it tightens up nicely.
FYI...this is a DBM #10 action, so it's really easy to test fit stuff, being able to remove the bottom metal.
Next is to glue them in. I'm slightly uncomfortable with doing that and the bedding at the same time.
Is there any disadvantage to doing the pillars and bedding separately? If not, what's best for glue? I was thinking epoxy???

I like devcon 10110.

Tex, I feel the way you do about trying to do it all in one step.

That's why I "tack" the pillars in place first (using the same bedding material as the rest of the job) and then, after confirming they are in place correctly, finish the job with all the "goop", letting it settle and squoosh into place, filling all the gaps, using the bottom metal and action screws to pull it in and bind it all together.

And, as Stang said, use plumber's putty when "test fitting" as a temporary substitute for the permanent bedding material. That way you can be sure the stock is inletted properly, you have good clearance and nothing is binding on the action. The whole point, when done, is to have a solid, non-binding and permanent action-to-stock fit. The putty will help you determine whether you are there or not before committing to the final step.

I think it looks easier to do it all in one step when bedding other styles of rifles.

It can be done in one step, but I am not that good. :)

Yeah, I'm going to do it as two steps.
My buddy has plenty of Brownell's bedding material, so all I need is glue for the pillars. Won't be buying a pound of Devcon for $50 for that, so I need to figure out what other glue is good for wood/metal. I was thinking JB Weld, but was told it won't do well with the wood/metal combination. I would think that any two piece epoxy should work, but I'm open to opinions/suggestions on that.

JB will be fine with the wood and metal.

use the same material you use for the rest of the job. just make up a small batch of it. or get a bit of 2-part fix-it putty from the hardware store. Can't remember what its called, but there are a dozen different varieties... pinch it off, roll it between your fingers and apply. Just a dab will do.

Yes. Any epoxy. JB makes some, too. I like the putty stuff cuz you can roll a bit of it into a little worm or similar shape, place it where you want by kinda "poking it" down into a gap between the pillar and the stock. Just enough to hold it for a minute, and then assemble everything for your test fit. Less messy and it won't run. stays put and yet flexible enough (for a couple minutes) to allow you to adjust the pillar a bit if necessary. Of course, for the second step, you want the material to be able to "ooze" everywhere, filling the gaps.

I imagine the pro's and more talented folks are cringing and shaking their heads at this advice. :) But I am not skilled at this, and know what works for me.

I tried that tootsie roll style epoxy in a plastic stock. It worked great!