Larry Wales listed the Newton in 22 Newton as having maybe less than 12 rifles ever made .Hell yes that is rare. I just do not consider that a normally produced caliber .I wonder why they never made more ? The 35 was a normally produced caliber and I consider it the rarest of that classification of the 256 , 30 and 35 . As less then 300 were made ,but yet its known world wide and was used extensively . The 40 as far as odd balls go is more rare than the 22 , maybe one known ? Bit its not , again a normal chambering . Would love to find one though !!!!