So all the cool kids at the Saturday night shindig are shooting Montana Gold Bullets, which to my eyes had the advantage of being the same price of the bulk Raniers that dissappeared off Midway right at the time my last box was running short. $293 for 3000 155gr slugs, including shipping? Yes please. These are FMJs, as opposed to plated totally-encapsulated slugs, with an exposed base. They also have what seems to be Montana Gold's signature brass-colored jackets.
I'm not fingering Montana Gold in particular, but my SIG P226 barrel was mirror-like, with infinitesimal lines forming parallel to the rifling, until I popped 291 of the bastards towards the rack o' despair, took the gun down three days later, and noticed what looked, and my heart skipped a few beats here, like lines of rust forming. What the hell? I don't carry it, I don't store it anywhere near moisture, I haven't shot it in the rain for nine months...surely it's not corrosion that's magically manifested its eldritch visage in my barrel?
I soaked in Tetra for 30 minutes and scrubbed vigorously with a nylon bore brush. Stuff came up, so I repeated that process three times. There's still brass-colored streaks running along the rifling, entirely unchanged. The texturing is limited to strips flanking the rifling lands, and the center of the grooves is still mirror fresh. The problem seems to manifest primarily at the bore; everything's still blinding immediately forward of the chamber.
The only variable that's changed is the bullets, and frankly I'm a bit miffed.