When you order the bottle to shroud clamps from Stuart at smwengineering he will require a few measurements from you in millimeters-
1. Shroud outside diameter
2. Bottle diameter- just because one guy says his impact bottle is 60mm doesn’t mean yours is. It can vary so measure at three different spots around the bottle to be precise
3. The gap between the top of the bottle and the bottom of the shroud- best way to achieve this is measure the overall height from top of shroud to bottom of bottle, then subtract the bottle and shroud diameters from that.
if you have Swiss ARCA rails from saber tactical under your bottle that has to be considered also.
The last piece of important advice on this- when calculating for that gap measurement and you are first pulling the overall measurement as I explained in number three, pull that measurement exactly in the area you plan on putting your clamp. Here’s why-
if your barrel already has a droop on it, that means the gap out of the guns block will be different at the gap closer to the end of the bottle, correct? So if you pull these measurements closer to the block where the gap is at it’s widest and install Stuart’s clamp up front more towards the front of the bottle where the gap is at the least, well, it’ll now force your shroud upwards which may or may not work out.
on rare occasions on guns where the droop is severe, I’ll add shim material between the shroud and the bottle to make the gap equal in appearance from one end of the shroud to the other end, then pull my measurements as outlined in step 3.
ive measured and ordered a lot of these clamps from Stuart, and he's spot on 99.9% of the time in what he sends back to you. If it’s botched up and doesn’t fit it’s more than likely you botched up a dimension so check thoroughly before you finalize the order.