Can a silencer (sound suppressor) be affixed to my gun in GMG?
In general, no, not unless you can prove that it can be done to your firearm. Some weapons cannot be suppressed at all, such as revolvers and shotguns. Others can only be suppressed with special modifications. Others still are fitted with sound suppressors by default, such as the H&K MP5 SD series (statistics for these and other suppressed weapons are listed in the Firearm Data Table). If you are really keen on having your weapon suppressed, bear in mind that the base Impact of your firearm will drop by roughly 25%, rounding down to the nearest whole number (e.g. 9g drops to 6g).