Bruce,A 7 mm hole for .22 is very snug. Especially at the front end. Asses to that, 7 mm in CAD is going to print smaller; perhaps 6.7 mm. You would need very good concentricity, and almost no angularity for that to work. Consider that stock Marauder baffles have an 8 mm measured hole in them. My suggestion is that you start at 7.8 mm (7.5 mm a printed) and then flare out from there towards the front. Make a version that seems excessively large holed, then make another that is tighter, and see if they sound different. Also, zero clipping should have top priority.Nice looking prints. The fracture is across the filaments at the clipped damage, rather than between layers. So, good adhesion between layers.
I went with a clip on sight for the LDC.https://www.gatewaytoairguns.org/GTA/index.php?topic=175527
Bruce, did you make a mold oven from a toaster oven? If so could you use it to powder coat the end cap?