The Russian’s have been on a sniper press blitz for a while now. Here’s another press release breathlessly repeated by a gullible western press:
In it the “7.62 subsonic and 12.7 noiseless” options are talked about….
Well, yawn. The Russkies have been pimping 12.7×55 subsonic since at least 2012, without every going to a widespread issue for their military forces, and the rather ancient at this point 9×39 subsonic round is still the bulk of their “silent, subsonic” sniper system out in the force.
Meanwhile, it seems like everybody in the US not jumping on the latest 6.5mm long range cartridge is building a 300 Blackout. Essentially subsonic sniper rifles the worst of all worlds, the energy levels of a pistol but the bulk and weight of a platform that doesn’t have the reach of a standard service rifle. There are a lot of drawbacks to having a dedicated “silent” sniper system.
The biggest drawback is that there really is no range advantage over your victims. If the infantry you attack can pinpoint you, well then your day just went south very fast. With a standard sniper rifle, you can engage beyond the range of 5.56×45 or 5.45×39 quite easily, and really only have to worry about medium machine guns or larger as an immediate response.
Now, there is tactical utility in having the capability. If an approach team can’t take out a sentry, but a sniper can from 200 to 300 meters away, then a suppressed sniper system makes good sense. However a 200 or 300 meter shot can be taken by a normal 308 Win pushing a 175 SMK at 1050 fps from the muzzle gives an impact at 300 meters that a “normal” load would have at 1000 meters (36.7 minutes of drop). Clearly the 308 sniper systems in use today can make 1000 meter shots, so the 300 meter subsonic shot is completely doable with good dope, and you don’t need a dedicated subsonic sniper rifle to do it, just attach a suppressor to the regular rifle and use subsonic ammunition.
The russians like to say that the 9×39 has an effective range of “400 to 530 meters” but I just gave you the drop of a high BC 30 caliber bullet at 300 meters. 400 meters is really pushing it for that stubby 9mm pill.
If you want subsonic bullet to go beyond 300 meters the traditional wisdom is that you are looking for really long, heavy bullets, like the 220 SMK. Unfortunately for you, a 220 SMK launched at 1050 fps has 35.2 minutes of drop out to 300 meters, a scant improvement over the 175 SMK, although it does arrive with much more retained energy than the 175. Still, getting hit with a bullet at 300 meters even with 330 some ft/lbs of energy is really going to mess up someone’s day pretty bad.
Subsonic sniping will remain a niche tactical trick for at least the near future. But eventually someone will figure out how to increase the range of the rounds to a level where the snipers can stay outside of the “service rifle engagement zone” of their targets.