Firmly believe you are shooting too light of loads. Try high brass through the Weatherby and no less than 1 oz. through the Rem. I bought a Weatherby semi auto for $50 because "it jams with everything". Was told by a friend that had one that it was designed for high brass. Never missed a lick after that.
After shooting many shotguns for many years I am of the opinion that 7/8 oz. loads are just too light to be reliable in a semi auto. Especially a 3" or 3 1/2" gun. I am also of the opinion that 90% of the semi auto failures is load related.
on the weatherby I was shooting 11/8 oz. And is high brass a type of shell or a brand? I have not heard of "high brass"