Actually, if those numbers are a reasonably accurate reflection of reality, Savage appears to have built more Model 40/45 Super Sporters than 1920s and 20/26s, but that was over a longer production run and through the entire length of The Great Depression.
The 1920's production run started with SN #1000 and went through around SN #10,500 for a total run of around 9,500 units. The Improve Model 20's production run started around SN #10,500 and went to just over SN #13,000 for a total run of around 2,500 units, for a total combined run of around 12,000 units.
It would be interesting to know what the actual production splits were in terms of the number produced in 250-3000 and 300 Savage in each of the cataloged styles. After owning around 100 of these rifles, my sample suggests that there were far more 1920s made in 250-3000 than in 300 Savage in a ratio of around 16 to 1. My sample of Improved Model 20s, the 20/26 style, suggests that they were made in almost equal numbers, with just slightly more made in 300 Savage than in 250-3000. Of course, the 1920 was in production for around 6.5 years and the Improved Model 20 was in production for around 1.5 years. Assuming that, for conversation's sake, these numbers are a reasonable reflection of reality, production of the 1920s averaged around 1,615 units per year and the Improved Model 20s averaged around 1,670 units per year. We know that production wasn't flat and that a large portion of the 1920 units were produced in 1920/21 in anticipation of market demand that didn't materialize. The changes made to the 1920 made sense due to the lack of market demand for the original design and the negative comments that gun writers of that day made about the uncomfortable recoil of the 1920s chambered in 300 Savage. The limited success of the 1920, Improved Model 20 (20/26), and 40/45 Super Sporters may be attributed to them being chambered in 250-3000 and 300 Savage, since neither of those cartridges has ever drawn much consumer demand in bolt action rifles. If they had, I think that there would be more Winchester Models 54 and 70 chambered for them, since those rifles were more successful than their pre-WW2 Savage contemporaries.
While the additional weight gained by a heavier barrel contour and more robust stock may have helped to tame the recoil of the 300 Savage some, those changes were of no benefit, at least no benefit that I can see, for the 250-3000. However, based on the rough numbers that I have gathered over the years, the changes made to "improved" the Model 20 had little positive impact on the average annual number of units produced. Consumer demand didn't change enough to save the 1920 from being replaced by the 40/45 Super Sporters and despite being offered in both 30-30 and 30-06, the 14 year production run only averaged around 1,150 units per year. Lots of "what if" scenarios to consider.
PS - 'sorry for the ramble.
