Gunsmithing DBM frustrations

[longbow62]

Hi looking for advise on DBM problems. I bought CDI bottom metal from Midway, along with one 10 round, and one 5 round AI magazine. I sent B&C stock to Chris for inlet. First thing I did was bolt up and cut screws. No big deal doing that, but mags would not seat. Had to shim with two washers before mags would seat and function properly. Of course now screws sent with bottom metal that I cut are to short to engage enough threads with shim. I recut the orignal action screws and they seem to be fine. Everything functions 100% now, although the mag engagement could be tweaked a little I think.

Also on a 700 action there is a putrusion at back of cut out for internal magazine with a threaded hole in it. It sits above and in front of trigger. What is it's purpose and can it be ground down? It ever so slightly putrudes past the upper edge of the top of the bottom metal? This seems to hinder the mags seating as easy as they should.

 

[claudesapp]

Re: DBM frustrations

If I am reading your post correctly, I think I would trim the catch lever instead of shimming the bm

 

[Gene Poole]

Re: DBM frustrations

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: longbow62</div><div class="ubbcode-body">
Also on a 700 action there is a putrusion at back of cut out for internal magazine with a threaded hole in it. It sits above and in front of trigger. What is it's purpose and can it be ground down? It ever so slightly putrudes past the upper edge of the top of the bottom metal? This seems to hinder the mags seating as easy as they should. </div></div>

If the protrusion is in the way, then the whole DBM needs to come forward (toward the muzzle) until it is flush or slightly behind the mag well rear wall. This should be the case if the holes in the DBM are aligned center to center with the pillar holes in the stock (assuming a stock with an aluminum block like the HS Precision). If it won't align properly, then you may need to take a bit more out of the front slot so that it will fit correctly.

I just had to do this on one to get it to fit right:

 

[longbow62]

Re: DBM frustrations

Okay I will look into why it protrudes in front of the mag well instead of it being flush. Thanks!

 

[Red_SC]

Re: DBM frustrations

Did you confirm the depth of the DBM, or test function to get the depth? Mine felt like it needed to be shimmed, but my caliper said I needed to take more off one side of the inlet- the front if i remember right. I used an abrasive bit made for a die grinder chucked in a drill press to deepen it into the aluminum bedding block, it came out perfect and functions smoothly.

 

[dmg308]

Re: DBM frustrations

Pretty sure you just need to trim the mag lever.Jeff cuts the inlet so the metal sits close to flush.Knock out the roll pin trim the top of the lever.

Go slow to test fit don't put the roll pin in just put a punch through the hole to hold the lever and test fit.Be care full not to take off to much or the bolt will skip over the rounds rather then feed.

 

[x ring accuracy]

Re: DBM frustrations

To start, are the rails of the DBM flush with the bottom of the stock? If so the mag catch lever needs to be trimmed down. Go easy as a little bit goes along way. Not a big deal.

 

[stockdoc]

Re: DBM frustrations

FYI, punch out the pin that holds the mag catch in place. you will see the mag catch has another pin hole to allow the catch to sit a tad lower thus enabling it to catch the magazine. no grinding or shimming needed.

 

[longbow62]

Re: DBM frustrations

Okay thanks for the advice. I have not had time to make any adjustments yet. Will start with the mag catch and see what it does.

Before shim the ten round mag rails were binding the bolt. 5 round did not bind the bolt, but was hard to get latch to lock.

 

[wnroscoe]

Re: DBM frustrations

Longbow,

I sent you a PM offering to walk you through the fix........you never responded

 

[pistolpacknpete]

Re: DBM frustrations

i have the same question i want to install a dbm on the b&c fully adjustable. anyone know a good place to send it? i would prefer it be done around the wichita ks area. Not badger theyre pretty pricy