Hi, dtn. I read that the russians used birch because it was a common wood and lighter than the walnut, making the stock less heavy.
The sucesor of the well tried Winchester 97 was another legendary shotgun, the reliable Ithaca Model 1937.
A pump action shotgun, with the ejection port in the lower part of the receiver. As its stablemate, it had a heat shield of perforated steel with a bayonet lug. Very reliable under the worst conditions, it was used by the amercian troops until the Vietnam War.
Credits: Inspired by the previous Ithaca 37 by Ace. Thanks to him! Cheers.