Looking at apples to apples (120-130gr bullets) the 277 and 300BLK don't appear to be all that different ballistically.
Where the 277 shines is with 90 grain to 100 grain bullets. The small case capacity really does a good job with velocity. On paper it looks like the 277 rivals the 6.8 with 90 to 100 grain bullets. Available reloading data says the Wolverine is running to within 90% or so of what the SPC will do.
Another plus, and a huge one in my book, is no proprietary magazines for the 277. While there are some good 6.8 mags on the market they're expensive, heavy and only hold 25 rounds. Or they're really long.
I have a barrel and some ammo on order. Fingers crossed the cartridge will live up to the promise.
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