Boolit sized, lubed/coated etc properly- why am I still getting leading? (pics!)
Rifle is a Marlin 336, originally a 30-30 that shot well. Unfortunately 30-30 is not kosher for hunting here so had it re-bored to 38-55 by JES. Barrel now slugs .377, have tried a number of different combinations- .379-.381, different lubes, gas checked and not- and most recently been using .380 Hi-Tek coated boolits @ 1300 fps and still seeing definite leading.
My understanding was that leading is caused by an improperly sized boolit, poor lube or excess speed. Having eliminated all of these issues I am still scrubbing lead out of the barrel after barely 50 rounds.
Thoughts?