I wouldn't cut up a full military example of anything to make into a 'sporter' as there are just too many already altered examples around to work on. From actions and bbl'd actions to rifles with cut down wood and drilled and tapped for scopes, pads added,,,any number of alterations that have taken them from the Military Collector field to the shooter catagory.
Some not altered too far or that may be salvagable dispite alterations that it's worth the work to 'restore' them to their prior Military status.
I've done that to a couple early MkI and MkI* SMLEs from the 1904/06 era,,sliding charger bridge and the so difficult to find rear handguard. I've still got another two in the works.
But I'm not opposed to building a sporter,,usually a pre-ww2 or even pre ww1 style European sporter on an already altered rifle.
What better way to bring the old rifles back to life than in the sporter form that many of the very factorys that made the Military versions also manufactured.
The custom gunsmiths of the day didn't do too bad either.
Sedgley of Philadelphia made hundreds of sporter 1903 Springfields.
All built on military parts bought as scrap metal from the US Gov't,,paid for by the pound.
Low # '03s recv'rs condemned both by the Gov't and most of the shooting press as a handgrenade in hand.
They were headed to the smelter if Sedgleys hadn't bid for them.
So much for romantic history.
Mine is still in one piece after nearly 90yrs as a sporter and is as fine a shooter (and looker) as any.
Yes there are a lot of poorly done sporter jobs out there. They were cheap, available rifles at one time.
Everyone had a hacksaw and a file in the garage or basement shop.
$5 to $10 would get you a military rifle of some sorts and probably some ammo at most any gun show. $20 would give you the pick of the litter.
My first Mauser was a as-new un-issued in the grease Loewe-Berlin mfg 1983 Model Mauser rifle in 7x57 complete w/matching bayonet and scabbard. Retail price off the rack,,I splurged,, was $14.99.