Tacsol 16inch heavy barrels

16inch x-ring barrel 

 fluted and threaded $399

16inch heavy barrel fluted and threaded $525

X-Ring: lightweight aluminum-sleeved barrel over a steel bore; designed to give you a heavy/bull-barrel profile without much weight.
The Firearm Blog +1
Heavy Duty X-Ring: more substantial/heavier construction, aimed more toward hard use and extended shooting, with more mass to help resist heat-related point-of-impact changes.
Both are 1:16" twist .22 LR barrels.