Gun has been slightly reworked since I took this picture. 16,5 mm top of helmet posed as it is. Should be like 18 or 18,5 mm if standing straight.
Here's a new montage as well as a pic next to Micropanzer SAS, Critical mass ARC, Peter Pig vietnam US marine and a contractor from Rebel Minis. Thanks again to those cool companies for letting me use their models.