In a presentation given by my classmate in 5th grade, I learned a very important lesson – WEIGHT KILLS SPEED. While the presentation was pertaining to the use of aluminum and alloys in automotive manufacturing this notion applies to nearly everything, including the amount of things carried at an op.
The simple fact is that the suppressor lives on the very end of your rifle and represents a large and heavy mass, causing imbalance and a hindrance in the ability to not only transition from target to target but overall mobility on foot. The desire to run a suppressor initially was born out of the necessity to run the longest possible inner barrel. At the time (circa 2012/2013), the belief was that 455mm was THE length to run and the aesthetic requirement to fulfill that 455mm length meant having to stuff a 16″ barrel on your carbine and add a suppressor to the end of that.
Reference my main rifle back in the day below.
The use of the suppressor hid the extremely long inner barrel and allowed it to be extremely accurate out to 300feet. However, because of the weight and length, it was 100% unfieldable in anything CQC-related and was a constant snag hazard in thick brush, thus eventually relegated to open-field duties, of which current-day ops are based less and less in.
Not long thereafter, it was determined that you could get comparable performance out of a 285- or 300mm barrel via over-voluming and thus, the cans were dropped basically overnight. You could now have similar range and consistency out of a much smaller package AND be able to wield it for long periods of time in urban environments? SIGN ME UP.
Nowadays the MK18 is run un-suppressed with 2 exceptions:
- Because of cylinder to barrel over-voluming, the additional rapidly-expanding air volume results in a report that is quite a bit louder than a volume-matched setup. The mounted suppressor, with foam, helps to damp* the sound and adds a small element of stealthiness. Polarstar users have reported a stark sound reduction using a suppressor with this theory.
- If I want the gun to have a little more punch. Since the gun is over-volumed (full cylinder), I can run both the 285mm and a complete 407mm barrel group that can be swapped in quickly on the field. This brings my FPS from 380fps up to 420fps with just a simple barrel change and a suppressor to hide/protect the inner. With this setup, the suppressor JUST covers the inner so the sound-suppressing effects are nil.
*damp as in, reduce. Not to be mistaken with dampen, which is to make moist.