You can find two custom bolters in my new Shapeways store. They are in detail and ultra-detail acrylic. Modelled around the real-life Kel-Tec RFB. The dimensions are to the big size, with the bolter approximately in 24mm x3mm x14mm and the silencer adding another ~7mm to the length. The Mor Deythan snipers should be in the same dimensions if you want any reference.
Thunderbolt Gun
Silenced Thunderbolt Gun
In the following weeks I will update the models with Chapters' iconography and combi variants.