Why reinvent the wheel? In GUN DIGEST 2000, page 106, Janne Pohojoispää published an article "Children of the 7.62x54R". Besides the more familiar (in Finland)5.7x53R, 6.3x53R, 7x53R, 8.2x53R and 9.3x53R he lists a 9x53R Urheiluase of Helsinki, a .375x52R by Jyri Jalonen to use .375 Winchester barrels for the Valmet, a .416x53R by Pekka Helenius and finally a 11.6x55R, a .458" cartridge on Sako case blanks. Both the .375 and the .416 versions feature an improved shape with a longer powder space and a shorter neck, the .375 resembling the 9.3x53R Swiss case somehow.