.303 British Muzzle Wear Gauge
What tool(s) were used by the armorers to determine muzzle wear on the No4 rifles.
For US rifles in .30-06 and .308 as well, the set of Troat erosion and muzzle wear gauges can help rapidly someone to make a first assessment of barrel condition.
What is the common way of doing that evaluation beside looking down the tube and stating: Oh yes, there's nice sharp rifling in that barrel.
I also know about using a loaded round inserted down the muzzle end.
I have looked on the Internet and I have found only about .30 cal. tools.
Thank you in advance,
BB