I believe that the .22 & .23-28-30 were before the .22-32-40 and were designed as a Schuetzen cartridge using a jacketed Mann-Niedner base-band bullet. They were allowed for a short time in Schuetzen matches until Lewis, Niedner and others started cleaning up then they were barred from the matches. The majority of varmint rifles from Niedner before WWI were .25 caliber using the Krag case and few using the 06 case. After the war and when Niedner moved to Michigan he brought out the .22 Niedner-Magnums a 25-35 necked to .22 and .22 Niedner-Magnum rimless the .25 Remington necked to .22 both very successful cartridges. One of Mr. Niedner’s varmint rifles was a repeater chambered in the 6mm Niedner-Magnum the .25 Remington necked to 6mm.
E.A. Leopold and others were a big fan of the .25-21 until the .25-20SS took over which is another cartridge you might consider.
