The meaning of SMLE

[Claven2]

No, polygonal rifling is a modern invention and it's rifled with sharp edges, just not with squared lands. Metford rifling is similar in principle, but there are no defined edges to the rifling - the lands and grooves are completely rounded.

The first time most ppl look down a metford rifled barrel, they get the impression the rifling is well worn and shot out, when in fact it's designed that way.