I've got 350 pieces of Remington 221 brass that I have been storing for the past 20 years or so. I bought them originally to go with my brand new 300 whisper upper made from a Shilen Select Match Air gauged 1/8 twist stainless barrel designed to throw Sierra 240 grain SMKs downrange at 1050 fps. Back then, one had to make your own brass. haha. Jokes on me.
Matt