Casey, just measured my 195 series barrel, which I assume would be the same as your 185. I was expecting one measurement back towards the gas block and a slightly less reading where the barrel steps down slightly halfway to the muzzle. Instead I am getting several different measurements, and the barrel seems to measure as fatter as I get closer to the step down. Right up against the strut clamp near the gas block measures .559. Halfway out to the "step" reads .583. An inch further down the barrel, right up against the forward strut clamp reads .586. After the step down, it measures .562. Weird.