for a holster for the mk23 +suppressor , the chest rig i use {viper spec ops} has a velcro pouch {think its actually for a regular pistol?} and i just had to cut a bigger section out the bottom , the guns big enough that it cannot fall through and because its high up the suppressor wont dig into the floor when kneeling down ,im guessing most chest rig setups have some thing like this that you can secure the mk23 down out the way ..