.300BLK is superior. Except...it’s not ubiquitous.
Were I starting out with what I know now, I’d go .300BLK ... but I’m not, I’m pretty deeply vested in 5.56, and the benefits of switching aren’t worth the cost.
Even were I to go all-in with .300BLK, I’d still keep at least one 5.56 rifle on hand precisely because it’s easy to feed from the existing supply chain. With .300BLK, I’d seriously consider buying a pallet ($$$) because I’m not confident in crisis & long-term availability.
Although hard to find in an AR, I prefer the 243 win round. Very plentiful, 100 gr hits hard. Obviously not up to 308 standards but does not weigh as much either.
SHTF:
- 300 BLK cases are commonly made from .223
- get a .300 BLK bullet mold
- can use some pistol powders
It actually is a better close range round. Use the same lower as your .223 AR.
I’m building up a couple on .300BLK for Household Six and I. I will make an upper in 5.56 as well, but I like what I read about the .300BLK.
AR10. 7.62 X 51. This is the best of both worlds. Dang thing is pretty heavy, though.