Originally Posted by kuduman
.300 blackout subsonic is pointless if not suppressed, and then it has the effectiveness of a .45 ACP pistol round, but I won't belabor that point since it's the flavor of the month.
Well, I don't want to hijack the thread, but a subsonic 175 gr. bullet is more similar to .40 than .45 ACP. May be more similar to 10mm, but the diameter is smaller and the bullets aren't designed to expand at that low speed. So it's likely LESS effective on human/deer size targets than the pistol rounds. Someone needs to design a 175 gr. thin-jacket SP for .300 BLK, but as far as I know, no one has as of yet. And the typical twist rates (that I've seen, but I'm no expert) won't stabilize the 220-240 gr. bullets, which are the ones you'd really want to shoot subsonic, though they may not leave enough room in the case for powder.
And the 110 TSX won't penetrate nearly as deeply as an expanding 75 gr. .223 round; the SD is way too low. It may be good enough, but a 150 gr. would be far better. The ballistics of the 110 also suck, beyond a couple of hundred yards. I'm not saying I know of a better option; it's just not clear what is a definite improvement over .223 for the military in the AR platform. For other purposes, .458 SOCOM (I love it when they reinvent the .45-70 and get all excited about it-- happens every decade) and so forth have their uses.
Can you stabilize 110 TSX supersonic and 175 gr. subsonic from the same barrel?
The subsonic rounds I have are 220 gr and 208 gr AMAX, which is why I compared them to a 230 gr .45 bullet. The 300 Blk subsonic rounds have a higher ballistic coefficient, making them easier to shoot more accurately at distance. Obviously, supersonic rifle rounds are much preferred to subsonic 300 Blk/.45 for deer/bad guys, but shooting 300 Blk subsonic suppressed is a lot of quiet fun.
1:8 barrel twist in my 10.3" barrel will stabilize all bullet weights all the way from 110 gr to 220 gr, no problem.
I'd have to disagree with your assessment of the 110 gr TSX round from the tests I've seen. That sucker moves fast, hits hard and expands reliably with plenty of penetration. 300 Blk can penetrate barriers better than 5.56. Ballistics of the 110 don't suck beyond a few hundred yards, not sure where you got that idea. Watch "300 Blackout Year" on YouTube with Travis Haley - he shoots a 300 Blk SBR at something like 700 yards, accurately on every shot. The 300 just had a slightly higher holdover than 5.56 past a few hundred yards, and no, the 5.56 is not more effective at that range.
Not trying to be rude or argumentative or anything, I just don't think you've accurately sourced some of that info. If you read up on the caliber you might change some of your opinions. The only downside to it right now is that's it's more expensive than 5.56, but the price is coming down. Now I've got to check out this .458 SOCOM that everyone is talking about....
