Re: Eddystone 1917
How do you know you have too much headspace?
You will need a special barrel vise to take off your barrel. These are generally on pretty tight. Just setting the barrel back isn't going to solve your problem, if one exists. You will also need to rechamber, and establish correct headspace. You will need a depth mike, reamer, headspace gage, and a lathe.
I'm thinking a trip to your local gunsmith is in order here.
Good luck on this.