Gunsmithing DBM Fit Question

[Deadman Pointers]

You'll have to excuse the silly question, but I've never worked on a stock where I didn't install the pillars before. I posted this in the DIY section, but it probably should have gone here first.

I picked up a Grayboe stock with factory installed pillars and their DBM. After a little while messing with the inlet, it turns out the ears of the DBM itself may not be flat. Said in another way, it does not rest flat on the pillars. In fact, the two contact points are at the front tip of the DBM ear where the front action screw goes and the back tip of the ear where the rear action screw goes. I can fit a .025" feeler gauge in between the the DBM and the rear pillar when the DBM is inserted hand tight.

Is this a problem to the point where I should begin flattening out the DBM itself? The inlet was CNC cut, so I assume it is flat. I'm going to be skim bedding the action anyways, but I never came across (or never noticed) this sort situation before.

 

[chevy_man]

I would get out the straight edges and start measuring to see if you can find one part or the other is actually out of spec. Just because something was cnc machined doesn't guarantee accuracy.

In your case I would go with the rule of modifying the cheapest and most readily replaceable part.

If you can get the bottom metal to fit with a few strokes of a file I'd be inclined to try it. If course if it's a $300 dbm, that may be nerve racking.

Straight edges and dial indicators may find either or both parts not truly straight. Could just be tolerance stacking.

 

[Terry Cross]

If the stock and bottom both came from Grayboe, this is 100% something that they should have the chance to address. Potentially one of your pillars or inlet is out of spec. If not that, the DBM could be out of spec. Bottom line is that you should get 100% flat to flat contact between the pillars and the DBM when tightened without any flex at all in the system.

If you try to fudge it and either the front or the back pinch point is off, you could also have feed issues or magazine seating issues. Neither is a good thing. Trying to correct this by adjusting parts that are wrong will put the OP firmly into another thread about "why doesn't my mags fit or rounds don't feed."

Give them a call. If they can't diagnose and correct over the phone, I'm sure they would pay to get the stock/dbm back and fixed.

./