Mossberg & Sons introduced the No. 45A takedown bolt action rimfire rifle in 1937, replacing the No. 45, and produced it for only 2 years, until 1938, when they introduced its replacement with the No. 45B.  The No. 45A rifle features a 24" barrel, tubular magazine that holds between 15 cartridges in 22LR caliber, 18 cartridges in 22 Long caliber, and 22 cartridges in 22 Short caliber.  The rifle weighs 6 3/4 pounds and its barrel is equipped with a No. 1A ramp front sight and a No. 2 rear sight.  The receiver supports a No. 3 receiver peep sight and the stock is a plain pistol grip version of birch with a walnut finish and non-detachable swivels with 1 1/4" loops.  This rifle had a retail price of $11.85 when it was introduced.