Kolebrander:

Welcome to the wonderful world of shooting in general and 1903s in particular!

Assuming your rifle was assembled properly and that parts are in good shape, it should be able to safely fire any .30-06 ammunition. Do you know why your dealer suggested using reduced loads?

Two questions: is the receiver unaltered? There exist a number of 1903s that were converted by the US Army into "Drill Rifles" by welding the barrel to the receiver and the magazine cut off to the receiver. The weld between the receiver & barrel was done on the bottom; to the cut off when it is in the up position. Any evidence of a weld in these places makes the strength of a receiver suspect.

Second: was your bolt headspaced to the barrel? A bolt must fit properly to be safe. Your gunsmith should have checked the headspace.

The Hornady is a good bullet. Since the 1903 is a bolt action, you can use any powder; there are no limitations as exist for a rifle, like the Garandicon, that has a gas operated action. I am not familiar with N110 but if it is intended for use with rifles cartridges & you have load data for it, it should be fine. The powders I have used include IMR 4895; IMR 4064; IMR 4350; Reloader 15; Winchester 748. I use Alliant 2400 for reduced loads with cast lead bullets.

I hope everything checks out OK and you can put your new rifle to good use.