Hello mckinney,

In looking through Speed's book, there are approx 750 random serial numbers listed across all of the approx 127,000 sporting rifles built from 1898 to 1946. Of those 750, 35 were in 10.75x68 caliber. That's about 4.6%. That really seems like a lot given all the different calibers offered over the nearly 45 years of Sporter production.