Gunsmithing Tweaking a DBM

[bush873]

New to this forum. Couldn't get an answer anywhere else. I've installed a Wyatt's DBM kit. Unfortunately it's hit and miss in regards to feeding. Its on a 700 action with a HS stock with aluminum block + Devcon. When torqued to 65"lbs the rear of the trigger guard sits 1/8" inside the stock. I know I need to play with washers for shimming. Should I just get it level with the stock or is there a better way to determine alignment for optimal feeding?

thanks for your words of wisdom
Bush

 

[jasonZ]

Re: Tweaking a DBM

It doesn't really matter how it looks from the outside, the inside is where the feeding issues are going to arise. I'd play with the washers and test the feeding of the round until I got it right. If it feeds properly and sits an 1/8th inch inside the stock then it's gonna be as close as you can get I'd say. I'd rather it work properly than it look good.

Also a note that I bought a CDI and the mag release was not right for my setup, which didn't lock the mag in high enough and the bolt would slide over the top of the round. I called Jeff and he sent me a new mag release lever, which was a simple install and a quick fix to the problem. I noticed this as soon as I put it in the rifle and inserted a mag. The mag had play, up and down, and when you inserted a loaded mag, the weight would let the mag slip down to where the bolt did not push the round out of the mag. Just a thought. Goodluck, Jason

 

[Captain Kirk]

Re: Tweaking a DBM

You won't be able to use the stock as a reference to deturmine where the bottom metal needs to be in relation to the action. The easiest way is to pull the action and bottom metal, purchase two pillars or fabricate a few just for meassurment. Once you can get the bottom metal and action spaced properly and feeding, you can deturmine where adjustment is needed, you may need to lift or drop your action and/or bottom metal.

Here are a few pics I took recently when I was inletting a action/bottom metal. First pic, you can see the bottom metal is seated too far out (pillars too long), the bolt was just catching the round but not reliably picking it up

After the bottom metal was seated deeper, you can see that the bolt will pick up the round more reliably

 

[bush873]

Re: Tweaking a DBM

Great advice. The pics were very helpful.


Thanks
Bush

 

[cal50]

Re: Tweaking a DBM

You can also tweak the feed lip on the mags slightly if needed. I had one mag out of several that missed a beat feeding. The lips were different so I adjusted it slightly for 100% feeding.

http://fwd4.me/09HY

 

[bush873]

Re: Tweaking a DBM

Thanks again. Great video.

Bush