Can someone tell me if their is any downside to a 1903 Mark I Springfield. Local has a beat up old sporter with a good bore that He is motivated in selling, (Price is right). I can see the big hole in the side of the action, any other gremlins or, good points.

Buy it. No appreciable difference because of the hole.

The original sear had a disconnector built into it so it dropped off & fired the Pedersen Device in semi mode only.
It doesn't effect the bolt action firing any, but it's there.

Someone rebuilding a MkI may be happy to pay for the sear parts for a military restoration though.

Gary D & Kutter. thanks for the information this gun came home with me this morning. This old Springfield has spent a lot of time on a saddle, and in the rocks. The Lyman Alaskan and the bore look to be good. I will bet it shoots good. Thanks again
David

There is a body of opinion that thinks the Mark I is a bit safer than other 1903s if a case busts or there is a gas leak, the big cut acts as a gas escape hole.