Well OK, I'll bite.
I have not finished the work. It has not even been shot once. Perhaps tomorrow, weather permitting.
The finished unit will have a side wall of carbon fiber (if I decide the weight savings are worth it). At this time it is PVC water pressure pipe. Strength is not the issue, weight is the issue. This thing weighs about five or maybe six ounces, which can be trimmed some by changing the baffle design.
ID is 38mm
OD is 42.5mm
Functional length inside is 120mm
OAL is 150mm
Internal volume
empty is about 12 cu. in.
There are 5 baffles, each 20mm tall inside.
There is an expansion chamber at the barrel end which is about 1.5 cu in.
The baffles are stacked against the muzzle end end cap.
There is a 1/2 x 20 UNF nut embedded in the end cap to attach to a rifle. I can print that cap so that the nut is not exposed. This will do for prototyping.
A touch of flat black paint should improve the appearance of the device but I won't need to do that till I've tested it. Who knows how bad it might be clipping?