Some older (often modified) Schuetzen rifles have been rebarrelled with barrels made of mild steel. I seem to recall the name 'Stressproof' or similar, referring to barrels originally intended for muzzleloaders but often used in the past for CF blackpowder cartridges as well. Repeated failures with this type steel have led to its abandonment by knowledgeable shooters but there are still plenty of 'em left out there. Many original early smokeless-powder barrels also fall into this category, that is, a mild steel that's only marginal in strength.

Remember Murphy: if it CAN go wrong, then it WILL go wrong!
Regards, Joe

You can lead a man to logic but you can't make him think. NRA Life since 1976. God bless America!