ODFWTrainer

I bought three Benelli M2 left hand 20 gauges 6 months ago for program shotguns at the Oregon Dept. of Fish and Wildlife. We wanted to upgrade from some LH Escort 20 gauges that tended to have issues. One of the Benelli M2s that we ordered had the exact same issue that Stew McKinney (OP) had. Forearm was sliding loose. I compared this shotgun to the other two and referred to a parts diagram on the Midwest Gunworks website (great place for spares by the way). Confident that we didn't lose this part, I called Benelli and they promptly sent me the four washer set free of charge. At $6-7 each on Midwest, I agree with Steve Rose and would call Benelli and ask for replacements. There seems to be a batch of these unfinished left hand M2s out there! Hope this is helpful.