Copper and powder fouling are removed completely and quickly with Montana X-Treme. Brushes should be neutralized after use as with any solvent containing ammonia. The folks from Montana X-Treme state that this solvent can be left in rifle barrels with absolute safety, and that soaking barrels with Montana X-Treme is fine. We suggest following any cleaning with a
good non-Teflon bore oil.
Sinclair, Issue:3B, Page:145