From Brownells . . .
The newest version of the popular Brownells BRN-180 upper – chambered in the 7.62X39 intermediate cartridge – is in stock and shipping now.
The new upper offers the same adjustable piston gas system and folding-stock compatibility as previous BRN-180 uppers but combines them with the globally available 7.62×39 cartridge made famous by various Kalashnikov designs.
Like all other BRN-180 uppers, the 7.62X39 uppers fit onto most standard AR-15 lowers as well as specially designed BRN-180 lowers available at Brownells.