Re: 50 Beowulf
All the big-bore AR's are a bitch to feed. I run a .458 SOCOM and if I didn't have the foresight to stockpile brass and powder I'd probably be in the same boat. However I was planning on reloading this cartridge from the get-go. Loaded ammo is soemthing like $50 per 20. Bushmaster/Hornady are vying to price the Socom and Beowulf out of the market with their .450 Bushmaster. They've been selling uppers for $499 and Hornady stock ammo at like $20 a box. The catch there, is that there are only 2 factory loads avaliable. Reloaders have been cranking out loads for it like crazy though, and are even using .458 bullets sized to .452 in their guns.
AA really put a handicap on the Beowulf and although open to debate, the Grendel as well by trademarking the cases. There are quite a few suppliers of Grendel ammo now, as well as manufacturers offering rifles cut with an equivalent chamber. Kinda like SSK's .300 Whisper cartridge and the 300/221 Fireball deal.
Bottom line its not cheap to feed the beowulf, and from the looks of it won't get any cheaper either. Keep your eyes peeled for brass, and snatch it up. Whenever I find SOCOM brass I snatch it up. I've been reloading the same set of cases for a little over 2 years now, pieces are on 12th sizing and no case stretch has been observed so I'm happy with that.
I feel your pain, but in the shoulder mainly.