Gunsmithing Pillar Bedding Question

[Midwestside]

I was getting ready to pillar bed a stock tonight and hit a small unexpected snag I was hoping to get some feedback on:

The setup:
McMillan Stock- factory inletted for Surgeon SA DBM and R700 action.

When I dry fit the pillars, the fit was fine on the rear pillar. However, on the front pillar the stock material depth appears to be much wider than the pillar height?(see pics below)? I didn't mic' it, but the stock looks about an 1/8" thicker at the front pillar.

I'm not sure if this is fairly common? But now I'm uncertain at what depth to bed the pillar...flush with top (action) or flush with bottom metal?
I'd be leaning towards bedding the pillar bottom face flush with the bottom metal, and possibly having to remove some of the stock material behind the lug before bedding the action? ...Unless that could be filled-in with bedding at that location?

Any tips would be appreciated. Most of the better bed jobs I've seen on this site have just a hint of the metal showing/bearing around the pillars when bedding the action and that would not be the case with this stock, unless I removed some material somewhere.

Front Pillar (bottom view):

Front Pillar (top view): note the pillar is recessed approx 1/8" inch

 

[Force_Multiplier]

Re: Pillar Bedding Question

get a longer pillar

 

[Midwestside]

Re: Pillar Bedding Question

Sounds simple enough.

But these pillars came with the DBM from Surgeon.
So I didn't think that would be an option for reliable feeding.
I suppose I should dry fit the the action to test feeding if going that route.

 

[Force_Multiplier]

Re: Pillar Bedding Question

the true purpose of pillars is to prevent the stock material from compressing... if the pillar is short it won't accomplish that...

if the pillar is used to set the depth of the bottom metal and it's short... then the inlet is wrong...

you need a gunsmith, you're obviously out of your lane.

 

[wnroscoe]

Re: Pillar Bedding Question

Dry fit it first (full assemble w/o bedding compound) and check F&F with magazine and rounds.

Call if you like and I'll guide you through it step by step over the phone.

cell 318-422-0421

 

[wnroscoe]

Re: Pillar Bedding Question

The pillars are the length they need to be. Longer ones arent needed.

 

[Force_Multiplier]

Re: Pillar Bedding Question

that pillar is either short... or the inlet is wrong... if you sent me that filled w/ bedding compound, you'd get it back

 

[wnroscoe]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Force_Multiplier</div><div class="ubbcode-body">if you sent me that filled w/ bedding compound, you'd get it back </div></div>

Was that directed at me?

 

[Force_Multiplier]

Re: Pillar Bedding Question

or anyone else that says that pillar is right

 

[Midwestside]

Re: Pillar Bedding Question

I'm going to mic' the difference in the stock material vs the pillar. Appreciate the advice, but I don't think mcmillan would have inletted it wrong. I have two of these stocks which are identical and they're both the same dimensions. I might have been over estimating the 1/8"

 

[Edds]

Re: Pillar Bedding Question

Once upon a time, a long time ago, inserts weren't used for pillar bedding. The whole pillar was formed from epoxy. But it does appear that either the inletting or the pillar length is incorrect.

 

[Force_Multiplier]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Edds</div><div class="ubbcode-body">Once upon a time, a long time ago, inserts weren't used for pillar bedding. The whole pillar was formed from epoxy. </div></div>

once upon a time no stocks were bedded either

 

[SSC]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Dry fit it first (full assemble w/o bedding compound) and check F&F with magazine and rounds.</div></div>

+1 then you will know what needs to happen.

 

[wnroscoe]

Re: Pillar Bedding Question

There's a boss on the Surgeon DBM that fits against the pillar. When the DBM is properly bedded and the fit is as good as it can be the boss actually forms a reverse image that’s recessed into the bedding. The pillar doesn’t fit flush in the stock where it meets the DBM inlet. That’s why I said dry fit first to check F&F.

There's more to this than you think and if you think the fix is a longer pillar your guessing.

FYI, I've bedded more than a few rifles and DBM's and use Surgeon DBM's exclusively for a reason. I'm not guessing where this is concerned. <span style="font-weight: bold"><span style="color: #FF0000">The pillar is the correct length</span></span>, the real questions are;

#1. Is the stock inletted correctly
#2. Has the correct receiver dry fit been established

 

[Edds]

Re: Pillar Bedding Question

So the answer to the guys question is, it fits flush on the action side?

 

[Force_Multiplier]

Re: Pillar Bedding Question

yes, you are all knowing... you have the awesome ability to tell it's correct through a picture on the internet....

 

[Midwestside]

Re: Pillar Bedding Question

wnroscoe,
I really appreciate you weighing in on this and offering your phone # for advice.

I overlooked the boss, and that looks to be the issue here.

I mic'd the differences in the stock vs the pillar height, and I was significantly off by the .125" guess. It is actually .07". And when you take the boss into account it should be very close.
Sorry to start the differences in opinions here.

 

[wnroscoe]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Force_Multiplier</div><div class="ubbcode-body">yes, you are all knowing... you have the awesome ability to tell it's correct through a picture on the internet.... </div></div>

No, I'm not all knowing and dont know everything. What I meant was if it's the pillar that was shipped from Surgeon with the DBM, it is the correct length. I've never seen one shorter or longer than needed.

The OP can simply bolt the DBM and receiver together outside of the stock with pillars to check F&F. Then put it all back in the stock and dry fit, dry fit, dry fit.........it's the only way to know.

 

[wnroscoe]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Midwestside</div><div class="ubbcode-body">Sorry to start the differences in opinions here. </div></div>

When people have strong beleives in what they do their opinions run just as strong. FM was in the military and an LEO, he cant be that bad

I've been called a know it all before, he didnt get my cherry with that, sorry FM.

My offer still stands for the phone call, it'll answer a lot of questions in a short amojnt of time.

 

[Edds]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Force_Multiplier</div><div class="ubbcode-body">yes, you are all knowing... you have the awesome ability to tell it's correct through a picture on the internet....


</div></div>
He's got nothing on us, you and I had the awesome ability to tell it wasn't correct through a picture on the internet. Too bad we didn't know about that boss.

 

[Force_Multiplier]

Re: Pillar Bedding Question

I actually knew about the boss... Surgeon just happens to be pretty local to me... I've also worked on a few....


our difference of opinion was that I said it was too close to call w/o having hands on, and told the Op to get help, because I didn't think he was capable...

William has more faith than I... I don't have faith that the pillar is perfect, i don't have faith that the stock is perfect, and i don't have faith that the OP can tell the difference, or that we can one way or the other from a picture...

so I still say he needs a 'smith... he has one that's willing to try to talk him through it over the phone, i also don't have faith that I could do that....

good luck...

BTW, I actually recommend LA Precision and a few others here, to my local customers who want things I don't offer.

 

[Force_Multiplier]

Re: Pillar Bedding Question

and yes, I know I'm an asshole....lol

 

[wnroscoe]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Force_Multiplier</div><div class="ubbcode-body">and yes, I know I'm an asshole....lol </div></div>

Never said or thought that. Were probably closer to the same than you might think

 

[Force_Multiplier]

Re: Pillar Bedding Question

no, other people say it man.. you and I are good.. but I'm getting comments in the SB right now about how I "Blew it" in this thread.

 

[Tripwire]

Re: Pillar Bedding Question

Pillars are easy to make.......just sayin'.

 

[Force_Multiplier]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tripwire</div><div class="ubbcode-body">Pillars are easy to make.......just sayin'.</div></div>

my point, and I personally like them just a hair proud... which usually does affect feeding, so i personally generally choose to start w/ a longer pillar...

other people may choose to take a little out of the action inlet, or even the bottom metal inlet... it all works....

IF you have a basis of knowledge to figure it out

 

[wnroscoe]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Force_Multiplier</div><div class="ubbcode-body">I'm getting comments in the SB right now about how I "Blew it" in this thread. </div></div>

Good things about friends is this, you can always count on them to bust your balls.

 

[jrbet83]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body"><span style="font-weight: bold"><span style="color: #FF0000">The pillar is the correct length</span></span></div></div>

They could have sent the wrong pillars? Or two rears?

 

[dinc]

Re: Pillar Bedding Question

The pillars on a DBM actually serve as spacers to keep the magazine in the correct positions relative to the reciever.

I don't know about Surgeon but Badger pillars are front 0.72" and rear 1.07". A factory Remington is front 0.75" and rear 1.25". Thus a some stock between the action and DBM needs to be removed to fit the DBM.

How long does Surgeon's instructions say the pillars should be? How tall are your's?

I suspect your stock was inletted for something else.

Roscoe know's his stuff.

 

[Midwestside]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dinc</div><div class="ubbcode-body">The pillars on a DBM actually serve as spacers to keep the magazine in the correct positions relative to the reciever. </div></div>

I'd agree, and to prevent compression of the stock material (their "true purpose" as some people refer to it)

Surgeon's instructions say the pillars should be 0.66". They were furnished to me to that spec.
The stock material between bottom inlet and action inlet mic'd close to .73"
However, the boss on the top front of Surgeon's BM adds to the 0.66" dimension to make up the difference, which I should have caught originally, but roscoe pointed out.

Stock inlets are all correct, pillars are all correct, feeding works correct when dry-fitted prior to bedding.
I was doubtful any of those were wrong from the start b/c these components are all from top notch mfg's (IMO)that don't make a lot of mistakes and I had two identical builds with the same "issue".

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dinc</div><div class="ubbcode-body">Roscoe know's his stuff. </div></div>
Very True. I've followed his threads before, and he was very helpful with this one.

 

[Ratbert]

Re: Pillar Bedding Question

I've started making a list of various DBM's pillar length spec, just out of curiosity what is the listed length of the rear pillar on the surgeon?

 

[Midwestside]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Ratbert</div><div class="ubbcode-body">I've started making a list of various DBM's pillar length spec, just out of curiosity what is the listed length of the rear pillar on the surgeon? </div></div>

1.075" for rear. And that's right off of their diagram/instructions for Short Action DBM.

 

[Ratbert]

Re: Pillar Bedding Question

danke.

 

[wnroscoe]

Re: Pillar Bedding Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jrbet83</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body"><span style="font-weight: bold"><span style="color: #FF0000">The pillar is the correct length</span></span></div></div>

They could have sent the wrong pillars? Or two rears? </div></div>

Yes, they could have dropped the ball but, with all the Surgeon products I've used/installed, I've yet to find a mistake.

Besides, I could tell by the picture that the front pillar wasnt too long or two rears were sent. I do have that mad internet skill you know