I like both but for different reasons.
More 1917 Enfields where produced during the WW1 time frame than 03's. So more Enfields seen service in US troops hands than 03's. Yes the Enfield was a stop gap measure to supplement demand for WW1 rifles for our troops and Springfield and Rock Island couldn't produce the 03 fast enough. Remington in NY, the Remington Eddystone plant and Winchester all produced 1917 rifles. Originally for England as the Pattern 1914 in 303 Brit.
In the grand scheme of things... neither rifle is more accurate than the other. If you had to get nit picky... a 1903NM purpose built rifle (which would've had a star gauged barrel on it and the stock fitting got more attention to it as well along with a tuned trigger if I recall correctly... than the 1903 but I'm talking standard service issue made rifles... neither is more accurate. I've rebuilt 1917's with the original barrels on them and scoped them or shot them with iron sights and bedded the stocks. It would surprise you if you have one with a bore in good condition how accurate they are. I picked up a sporterized 1917 Remington for my brothers wife who wanted to get him a gun as a Christmas present for hunting as he only had a lever 30-30 and only had $200 to spend. So I bought one off of GB (this was about 10+ years ago). Yep for $200 including shipping. Crown wasn't the greatest so I touched up the crown on the shortened 22" barrel, bedded the stock because it was cracked, the receiver was already d&t for a scope base and I thru a old straight 4x scope I had laying around on the rifle. Think it was a old Bushnell I had laying in my box off extra stuff. That gun with box ammo shot consistent 3/4moa groups. Being as I know how much of a butt head my older brother is.... I honestly didn't feel he deserved the rifle. I should've kept it for myself and went and found another. Anyways I got it to his wife... she surprised him with it for a Christmas gift and he blew a gasket because she spent $200. Never got a thanks for all the work I did to it for her to give it to him...yep should've kept it for myself. LOL! Anyways....
Standard issued service spec rifles both had straight grip stocks. The later type C stock I agree is more comfortable for overall shooting.
The 2 groove barrels seen on 1917's are replacement barrels during a rebuild process. All standard/original 1917's should have a conventional 5 groove rifled barrel with a
left hand twist rifling. If you would shoot both side by side... the guns will torque differently.
All 1903 barrels would be 4 groove
right hand twist. Both guns are 1-10 twist barrels. It wasn't until the 1903A3 rifles did the Springfield's get 2 groove barrels or if a earlier gun went thru a rebuild process it might have had a 2 groove installed. All 2 groove barrels where cut rifled. Broach or button where not allowed on 2 groove barrels. All 1917's and 03's had cut rifled barrels.
Both receivers have a square thread 10tpi. The 1917 receivers have a 1.125" major diameter thread. 03's have a smaller major diameter thread about a .100" smaller. Does it effect anything accuracy wise? Nah.
1917's and early Remington 30 Express rifles are cock on closing when you rack the bolt. Later 30 Express rifles where done at Remington to cock on opening. Is one system better than the other? I'll say no. In terms of speed to manipulate the bolt... I'll say no. It's what your use to.
Here is a pic of my Rem. 30 Express that I've been working on a rebuild with a custom stock. This is a factory cock on opening gun. After putting a new barrel on it in 30-06 (22" finish length) I sent the barreled action out and had it re rust blued which is period correct for the gun. Not hot blued.
Ever seen a guy run the mad minute drill? Look up some videos on it. I think the record set with a Lee Enfield which is cock on closing... was just shy of 40 hits on target at 300 yards in one minute. Doesn't matter if you agree with it or not... that's frickin cruising with Enfield bolt gun. The average rifleman was in order to get his marksman badge... was suppose to get 15 rounds off in one minute and all rounds score on the target at 300 yards. Think it was a man size target. I've seen guys at hi power matches get around 15-20 rounds fired in 70 seconds prone with a Winchester Match rifle and doesn't matter how you cut it... that's running a bolt gun lightning fast.
Later, Frank