Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.
I am considering making a 3lug mount for my new mke t94 mp5 clone.
Does anybody know how strong the spring has to be. Is 150N (31 lb) enough?
How can I add pictures?