likely the .30-06 is correct.....further that's an extremely strong action.......most 1917 Enfields were made by eddystone. These normally have case hardened actions and are not considered as good as the guns produced by Winchester or Remington. The Manufacturer is stamped on the front receiver ring. Remingtons are considered the best, but the Winchesters have been used for magnumizing a lot too. I bought mine for $10 in Sacramento at a Sears store in 1966. I did a lot of work to it and today it's a .375 H&H magnum.....

If you have an Eddystone....use it...it's a fine gun and will serve you well. If you have a Winchester or Remington, you could have it rechambered to .300 Win Mag for very little and use the same barrel!!

In case you wanted to know!!