I am also re-creating a Lee Speed on a No1 action which has already been cut down to 25". The barrel is well worn but I am going to try very hard to make it shoot in its original.303. If that doesn't work I'll be looking to re-bore to .35 or .375. I'm not sure, however, that there is enough meat in a No1 barrel to re-bore to .375 (i's .668" at the muzzle). I'm still trying to research this point. Have you any knowledge about this?