"tinker": "Using rifle bullets as plug-gauges?" - YES.

The Russian methods are always simple rosary, and based not only on experience of basic wars in Russia 1905 years - 1917 years, 1941 year - 1945 years, I do not take the Spanish company into account, and many other local wars after 1945 . It is large experience of hunters of Russia also .
It only one from books allowing in the way of life to master the weapon of,- it has the applied value
http://arch07.narod.ru/potapov/index.html
http://arch07.narod.ru/potapov/part9.html#9-11
(a language is Russian, but pictures are clear to all).