This is a interesting rifle that just appeared out of Massachusetts. It is an original 1909 Springfield 1903 with a Winchester A5 installed. I've shown it to a lot of experts and I think the general consensus is, it is probably one of the early Star Guaged Match rifles, and it might have been a Marine Match rifle as well. But as with anything of this time period, it's always hard to prove 100%. The conversion seems to be of the time period and probably was done in WWI or before. The rifle, except for a modified trigger does not have any of the later National Match modifications done to it. But that would be correct for a Star Guaged Match rifle made in 1909.
The serial is 368496 and has a 6/09 SA barrel.