If your rifle is still in production, contact Mossberg. If not, contact Vic Havlin at www.havlinsales.com. Mr. Havlin and his wife Cheryl run the Mossberg Collectors Assoc. Be advised that a bolt is not simply a "drop in" but will require fitting to the gun. Improper headspace is a very dangerous condition that can arise when a bolt is too short.
Just like a bolt action rifle.
mossberg
100-500
300 or so
Your Western Field model 37 bolt action rifle was made for Montgomery Wards(Western Field) by Mossberg and sons.The Mossberg model 30 and your rifle are one and the same.The Mossberg model 30 single shot .22cal rifle was made from 1933-1935.
100 or so
50-350 usd
It was made by Mossberg around 1930 plus a few years. It was a low budget bolt action rifle Mossberg model 321 or 320 under the Western Auto name
No sn data
50-200 usd
10-700 USD depending on specifics
Blue Book of Gun Values