I purchased a metal rib from Midway. Fit perfect and the finish was good. Better then the plastic ones that come on the 600 / 660.
CVMW, Did you make the second batch of bottom metal different ? RJM of the campfire purchased 4 of them. I have one of them that he ordered. I haven't tried it on my rifle yet. RJM stated that the front hole wasn't drilled deep enough and the rear hole is drilled too deep. This means you have to cut the rear screw and then find a longer screw for the front. If you campfire members all like this guard, what did you all use for screws ? I will admit that this guard looks great. Finish is nice and smooth. I'm afraid that if I tighten the rear screw too tight it will go right throu the hole and break the guard.
