Direct ThreadA direct thread suppressor is the simplest type of mounting system. In this case, you simply have a weapon with a threaded barrel and screw the suppressor directly 0nto it. Think of the movies where somebody is attaching the suppressor directly to the end of their barrel - this is a direct-thread mount. The primary advantages of direct thread suppressors are simplicity and bang-for-the-buck. Many people also associate increased accuracy and more repeatable Point-Of-Impact shifts with direct thread suppressors; although, that is changing as newer and better mounting systems are coming onto the market. The primary disadvantage of direct thread suppressors is that they can tend to come unscrewed on their own if you're doing a lot of shooting. As a general rule, most people prefer direct thread suppressors on bolt action and other single-feed style weapons; although, that isn't a hard & fast rule. There are several direct-thread suppressors that are made specifically for high-volume weapons - like Griffin Armament's Spartan 3 or Sig Silencer's SRD556.
Locking Quick AttachWhen most people think of a 'Quick Attach' suppressor, they're typically thinking of a locking quick attach. In this case, you'll thread a flash hider or muzzle brake onto your barrel (which still has to be threaded) and the suppressor will lock onto the mount instead of threading directly onto the barrel. One major advantage of a quick attach mount in general is that the mount itself acts as an adapter. As a result, you'll often find that people who are running a 7.62mm suppressor on their 5.56mm weapon are using a quick attach adapter since the threads of the two weapons are different. On top of that, a locking quick attach also prevents the suppressor from coming unscrewed when doing any type of high-volume shooting. As a result of those advantages, you'll find that most people tend to prefer locking quick attach suppressors on semi-automatic weapons - like the AR15. The main disadvantage of the earliest quick attach systems was a loss in accuracy - and it tends to be most noticeable with tooth-mount locking systems. (Tooth mount systems rely on teeth around the mounting device to hold the suppressor in place.) More current suppressors, like the Sig SRD models or SureFire 300 SPS, can actually have better accuracy than their direct-thread cousins.
Non-Locking Quick AttachA non-locking quick attach uses a flash hider or muzzle brake on the weapon; but, there is no locking mechanism at all. Earlier generations of these mounts tended to be the worst of both worlds; but, modern taper mounts have changed that significantly. There are several reasons that taper mounts work so well:
- They provide significant surface contact between the suppressor & mount - which acts like a friction lock. As a result, a taper mount suppressor is far less likely to come unscrewed than a true direct thread suppressor.
- The taper actually aligns the suppressor better and more consistently than a true direct thread. Even though direct thread models are excellent for accuracy & repeatability, the taper mounts are often better.