For the .45 Government, best results will be with a piston assisted (called a Nielson device) suppressor like the AAC Evolution .45, or the HEMS. Both are very good, but they won't be as quiet as a 9mm, as others have mentioned. AAC's are able to be changed out so that they can go on different types of threading, hence use on a 1911 and a SIG or HK. Some other brands don't offer this, such as the Gemtech Blackside, which down not use a a piston, but is very light, and works most of the time on most guns (guns can be fickle. They may need lower pound springs, or be slicked up/broken in well). I have heard the Blackside on an HK USP-T, and it worked and sounded good. I have an older AWC Nexus on a 1911, but the can is too heavy, and AWC charges too much for adapters to other barrels/guns/threading. The HEMS has a good reputation for sound suppression on a .45, but I have no hands on experience. I wouldn't mind a Blackside...smalller and lighter than the piston assisted cans. Check out youtube for some videos on suppressor of various types.