OK, sorry, but I'm gonna be the Grinch here. You can't build a rifle if you have little or no money. The days of getting great military actions for $25.00, and take-off barrels for $25.00, are long long gone.
I would predict that it's going to cost at least $100 to get a good action, and even that is going to take alot of looking. I imagine that you could spend lots of time at gunshows and find a beat up 98 mauser action for $50 or so, but then you are going to have to take it to a good gunsmith and spend the money to have him totally check it out, including magnafluxing it. That's going to cost money.
You said your friend is a mechanic, but not a machinist, and it sounds as if he has little or no experience in installing and headspacing barrels. I just don't think he is going to be able to do this by himself (except on a commercial Savage action), so you are talking about spending a fair chunk of money just to get a barrel fitted to the action by a gunsmith. There will be very little that his son can take part in.
My advice would be, that for a great first father/son project, you friend would be better off buying an old military mauser in a popular caliber (7mm Mauser) or a good named brand commercial bolt action, that are cosmetically beat up but mechanically sound, and have fun RESTORING or SPORTERIZING it. Yes, they will have to pay $100 to $200 for the rifle, but after that, they can go slowly and do things that a beginner (and his son) can do well together.
Strip, sand, fill and refinish the stock. Replace the trigger with a Timney. Replace the safety. Clean up the barrel with solvent, paste, and maybe bore lapping, and see how she shoots. Replace the iron sights. Drill/tap if necessary for scope mounts. Jewel the bolt on a drill press. Maybe try a home blue, or a bake on finish.
And, after doing all of this, if the barrel is just too shot out, then buy a surplus military barrel, or an old take off barrel, and have the gunsmith install it. Then glass bed the action.
Your friend's son will have a great time, and will learn how to do alot of things, if he is taken through this process. And each step can be done slowly, with a relatively small amount of money.
This task needs to be approached from the viewpoint of entertaining and educating the son, not building a custom rifle for the father.
Been there and done it.
P.S.- If you can find a beat-up full-size 96 Swede Mauser, that would be a great place to start. The barrel can be shortened. The military stock can be shortened and reshaped by hand. You can buy triggers, and peep sights, replacement safeties, cock-on-close kits, and lots of accessories. I think Midway even sells new barrels in two other calibers that will go on the Swede. Can't remember which. Maybe the .250 Savage and the 7 Mauser?
Best of luck, Mannyrock
