"RA 17 should be Rock Island Arsenal..."
Uhm....
NO.
First off, Rock Island never loaded small arms ammunition. I believe they had a shell filling works, but Rock Island was a materials arsenal during World War I -- leather goods, equipment, firearms, etc.
Second, as others have noted, that's a .30-40 Krag cartridge, but loaded by Remington Arms at their Bridgeport, Conn., plant in 1917.
The R on the primer means Remington, which means that it's a commercial primer, which means that this particular cartridge was likely among the first lots loaded in 1917 after the Government let the contract for .30-40 Krag ammo.
It's likely that all of Remington's military contract primers were going into .30-06 production, so they used primers from the commercial side of the house until they could catch up.