Are you sure the gun is chambered for 3 1/2 inch shells? The longest 10-gauge NPEs I've found offered back in those days was 3 1/4 inch, but most were not offered over 3-inch. In 1901 the UMC EXPERT NPE for bulk smokeless powder was offered up to 3 1/4 inch in 10-gauge --
and the UMC UNION NPE for black powder --
As were their BEST quality brass shells --
By 1910 none of the 10-gauge NPEs for smokeless powders were offered longer than 2 7/8 inch, with only the paper and brass NPEs for black powder offered in the 3 and 3 1/4 inch lengths.