We've talked before about how long, heavy, bullets at low velocity are more likely to yaw on impact. However, I've been led to believe and seen enough actual gel tests to conclude that yawing is not consistent unless high velocity bullets are specifically designed to do so.
I've read that the 220-grain Sierra Match King in .300BLK has been used 'operationally' (whatever that really means I do not know), but my understanding is, that it's use is primarily limited to things like sentry removal or other types of close-range covert work. Shot placement will emphasize immediate incapacitation (i.e., head shots). If you think about the roles that 147-grain subsonics from MP5-SDs were used for, that is now the realm of the .300BLK. I would figure the 220-grain SMK or the 190-grain Hornady Subsonic-X have superior terminal ballistics to a sub-sonic 9mm. However, for all intents and purposes sub-sonic .300BLK is just a big pistol round.
The advantage to a Rattler/other .300BO specific platform is the ease of suppression and the ability to swap to a far more effective loading when silence is no longer needed (i.e., the 110-grain Barnes loads) and gives you ~250-300y (maximum point blank) ability.
That Rattler is kind of a niche tool in many ways, but it is a much wider niche than pistols or SMGs. I'd rather carry a Rattler, MCX, adjustable gas-system equipped .300BO with a 10" barrel and a bunch of 110-grain bullets and a few mags of 190 or 220 subsonics than a rifle and SMG or rifle and suppressed pistol.
First I’m in no way a tier 1 anything. But my understanding is the subs are used when quiet is key. Once it’s a fight and everyone knows you’re there, use the TTSX supers and your weapon is louder but more effective. I presume they want a sub round that’s got the best terminal ballistics a sub can offer for obvious reasons.
I have subs for my 300BLK but use them to show off how quiet the gun is to my friends and for steel matches. If I have to use subs to be extra quiet while shooting people CONUS, the world as we know it is no more. That’s the niche use they have in my opinion - they do things overseas that most of us will never know about. It’s one of those things that doesn’t really translate to most of us. Buy brand X rifle because it’s mil spec and passed the torture tests at SOCOM? Cool! It’s reasonable to say it will be a good choice for us stateside because it should easily hold up to our use. But if SOF personnel need subs to drop monsters... that does not mean any of us here need them. Use supers and drive on.
Give me a day or two to come back to this. I’m up to my ears in NPO stuff right now, and the mind is racing a bit much for a coherent answer this second. If I don’t post a lucid answer by end of the week, call me out by name to remind me that I said I’d address this.
Thanks for your patience.
You can get much more of what you want with a kind word and a gun, than with a kind word alone.
I could give the watermelons a pass, but if he says “hydrostatic shock” one more time I’m out.
Have the NRA Attack Ninjas silenced MAC, yet? I watch his videos. I'm not sure whether I should be drunk or not when watching them, though.
''Politics is for the present, but an equation is for eternity.'' ―Albert Einstein
Full disclosure per the Pistol-Forum CoC: I am the author of Quantitative Ammunition Selection.