I recently ordered a custom case from mycasebuilder for my modified Glock 41. The Glock 41 is an extended slide .45 ACP with a 13 round double stack magazine. This is my bedside gun, and has been modified with a set of fiber optic sights, a TLR-4 laser/flashlight, a full Pyramid trigger system upgrade (set for a 2 lb pull), and a SilencerCo Osprey 45 Suppressor. The case is from Pelican. Pelican cases are tough, durable, and have an excellent reputation. This one, as is typical for Pelican cases, is overbuilt. It is O-ringed, so it is completely waterproof at depths that even I won't dive to. It's also positively buoyant, so if it's dropped overboard, it'll float, at least theoretically. I have not checked to see how buoyant it is, and obviously this will be affected by the weight of the contents. It includes a pressure equalization valve. This is important, because if you travel with a case like this to a lower altitude, the pressure differential between the inside and outside of the case can make it very difficult (or impossible) to open. It is secured by four double latches, includes a combination lock, and can be additionally secured with one or two padlocks. It is TSA approved. It also includes a shoulder strap to make carrying it easier. Mycasebuilder custom cuts the foam, and they have a 'screw up replacement' option just in case. You can select from available shapes, set dimensions for simple round/square/rectangular shapes, or upload a photo that can be used to create a custom shape. Location of finger holes (if any) is customizable. Their selection of shapes is very good. I used their shape library for the spare magazines and the TLR-4. The spaces for the holster, mag holster, ammo boxes, and suppressor were created by setting dimensions, and the Glock 41 was a custom shape created from an uploaded photo. They do have a G41 shape, but it's standard. I did the photo upload to accommodate the extended threaded barrel. Everything fits perfectly, so I won't be testing their screw up protection plan. The only negative comment I have is that the case, which comes with a default combination of 000, does not include instructions on how to set the combination lock to numbers of your choice. It's nothing that can't be found with a bit of Google-Fu, but it does seem like something you'd include in your packaging. The case is not inexpensive, but no Pelican case is. This one is listed on their site at $272.72 including the custom work.