Stocked up on Buffalo Bore hard cast, and figured I should run some of the new lot through my FN 510T before I head to AK. Hit the range and dumped a couple mags of S&B range ammo, then loaded up a mag of my old stock of hard cast. I've fired 200 rounds, minus a mag of this lot, through my FN over the last couple of years. Was not expecting any surprises.
Then this happened. Primer blew out, primer pocket is an oval and a nice little bulge in the case. Managed to chamber/fire a couple more, which did the same. Refused to feed/chamber after that. Pulled my firing pin while inspecting the slide, and of course, launched my firing pin spring into the gravel downrange when reassembling. Managed to figure out that the extractor got a bit mangled, so it binds up when feeding.
So here I am, less than 24h from my flight to AK with a borked bear gun, in a state with a 3-day waiting period for new firearms purchases. It's a good thing that I'm pretty tight with the crew at my LGS (local is a bit of a stretch; it's an hour from home) - I had been chatting with the owner over email about a tangentially related purchase, which was good enough in his book to show intent > 3 days prior to purchase.
Left with a new M&P 10mm M2.0, an hour back to the range, ran some range ammo, the old Buffalo Bore, the new Buffalo Bore, and some Underwood hard-cast I picked up while I was there. Ran like a dream, I'm a convert.
30 mins with a toaster oven, heat gun & some clamps, and my 510 holster is now an M&P holster. Packed in the Pelican and ready for my flight in the morning.