Just curious: what do y'all use for cutting fluid when final hand chamber reaming/throating? I have used everything from some 55 year old Army surplus lard oil, to ATF, motor oil cut with kerosene, and even once I used Breakfree- all with total success. Like I said, I'm merely curious as to current consensus (if there is such a thing).

I use high sulfur cutting oil.

Ridgid Dark Thread Cutting Oil

All I have used so far is that Viper Venom stuff.......cut about six really nice chambers so far!

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Sulflo cutting fluid. I think they hyjack a truck load of ridged dark sulfur base cutting oil and slap their on label on it. If it looks like a duck - - - - - - - - -

For all my reaming I use Butterfield cut with 30 to 50% Tap Magic

Tapping and boring I use Butterfield straight

Tap magic.