had an enlightening weekend with my new borescope.

[RDavies]

I just bought a borescope for work, which just happens to also be perfect for rifle barrels. I had a look through about 12 of my barrels, ranging from factory barrels, shot out hummers, barrels which have never shot well, and barrels which are now working well. I also took it to the local range and looked through a few barrels and visited some friends today to check thiers out.
As well as some other recent tutoring, I remembered a few things Garry Hunt showed me last year at Canberra so I would have a bit more of an idea what to look at.
After now looking at about 30 barrels with it, a few things have become apparent. Barrels which have always shot realy well, looked spot on internaly, with all grooves,lands, contact/sealing areas being very uniform all along the bore. barrels which have had fouling problems, showed the causes, apart from one which looked great.
Some suprises were that a few of the realy good shooting barrels (which all happened to be either Maddco or True Flites showed very little or no fire cracking even after 800-1000 rounds, where as the overseas barrels showed varying degrees of firecracking after between 80 to 200 rounds. The worst fire cracking was in my 6mm with only 80-100 shots since its rechamber. The gunsmiths had said they were great to cut, machining like butter, maybe they are softer than the Maddcos? The barrels (both mine and other peoples) which had never been great showed machining marks in the middle section of the barrel mostly and the contact or sealing areas along the lands and grooves showed gaps and misses long the length. It seems that the localy made barrels are at the top of the game from the small sample I have seen.
I will take it along to Canberra Queens if anyone wants to have a look inside their tube.