I don't have a 7mm-08 but i do have an 18" .243 and it's both loud and breaths fire lol. Running 105gr Berger VLDs at 2700fps (max load). Has a bit of a muzzle flash
Most people go .308 for 16-18" rigs because the higher the overbore ratio on the case, the more hit you're going to take for chopping the barrel short.