Enhanced Rail for Samson Evo (BRO) .308 and Free Float Hand Guard Clearance

AR/M4 Beyond 5.56/.223
1

I am wondering if I am looking at an issue here (with the limited lower gas block clearance) using this 12.5" Evolution Rail. :nono: I like the Samson rail (made for Black Rain Ordnance) very much and look forward to trying this (but don’t really like the accessory rails). The block is a Badger Ordnance MK12 Low Profile Gas Block .875 ID. The barrel is a SAOD LW-50 (4 Groove) 1:10 twist Polygonal Match AR-308 16” DMR Barrel. I suspect the larger diameter barrel is part of my clearance dilemma with using this more narrow designed (for more comfort in handling) OD rail. I would like to put an AFG and bi-pod on the rail forward as this still gives me a nice round comfortable area for my hand twords the rear of the lower rail. The larger OD barrel will possibly flex less, but even with the BRO comp pushing down? My dilemma is drilling the two holes for the enhanced rail if the hand guard does not work out. I had to cut the accessory rail backing plates in half, shorten their screw length and flatten the head base to get this YHM 7" rail to attach correctly. I can’t seem find too much info on needed block clearance but did see a review of a LWRC REPER on YouTube that showed some movement with compensators and gas block rubbing was discussed (link below 2.5 minutes in). Anyway I filed the corners off the bottom of the gas block to get it just off the interior ribs of the hand guard. I do plan to bead blast and clear coat (matt) the barrel for this .308. Anyone think this will rub or stress the HG?

http://www.youtube.com/watch?feature=endscreen&NR=1&v=riM7uKpakJo

2

I know this isn’t gonna help your dilema any, but any chance you could post up some pics of the rest of your BRO build?

3

I am sorry the pics are not so great. It’s a bit of a monster and I had to shave a small amount of material to get the rear pin from the JD lower in the BRO upper, but I think they match up well. Thanks for looking.

I decided to go for it and make the lower hand gaurd rail a permanant attachment. The backing plates get around the gas block and I can adjust the hand guard to give me about a business card thickness or just under 1/32" clearance for the lower gas block. The HG comes on and off easily enough to look for rub marks or problems. Once I get the holes drilled I will post it.

4

Lots of holes - ouch:eek: - Screws and backing plates done and ready for locktite.

Finished install with screws nice and flat.

Attachments fit perfect

View of backing plates, good solid feel, would not bang in nails with it, but looking forward to bench test.

5

Damn good looking rifle and looks like you did a great gob of figuring our your dilemma! Don’t see a lot of Black Rain builds around the net, good to see someone else using their receivers. How does that barrel shoot? Thanks for the pics.