It's got a longer range of effectiveness. 22 caliber rim fire long rifle round in your 12-year-old plinker). At about 3,000 f/s, this round screams out of the barrel. If you're hog hunting or defending a position against an onslaught of zombies a football field away (or maybe significantly closer), you want this kind of pinpoint accuracy and speed so they don't end up on your doorstep. The 5.56 is, of course, the standard AR-15 round for good reason. Who doesn't want to chamber something called a 300 Blackout? When to Use the 5.56 Less Gas in Your Eyes. And with either 300 blackout round-subsonic or supersonic-the gas blowback is less likely to block your view in those close quarters, when compared with the rear gas expenditure of a 5.56. The supersonic 300 of course is not going to behave as quietly with a suppressor, but the increased velocity added to the heavier 300 round will come in handy when I need that shorter barrel but a bigger boom. If I'm weaving in and out of structures, fighting closer in, this is the round for me, both the subsonic and supersonic versions, because they operate well in shorter barrels.Ī Strong Punch Closer In. Ideal for Shorter Barrels. Speaking of barrel length, ideally I want to have as short a barrel as I can without sacrificing the performance of a round. But its stealth capability and effectiveness in shorter barrels make it ideal for use in close contact situations. So it may not have quite as much take down power as its supersonic sibling. The downside of a 300 subsonic is that it's a heavier round with less powder and thus is traveling slower. With a good suppressor, the subsonic can take down an attacker without necessarily alerting his friends in the next room. The round comes in subsonic (less than 1100f/s) and supersonic varieties.Įasy to Suppress. 30-caliber round originally created for shorter barrel rifles and closer-in shooting, such as in CQB and urban scenarios. The rounds you choose for a given application-target practice vs tactical readiness vs hog hunting-will play a huge role in your success rate. The AR-15 is probably just about the most important rifle you'll ever add to your arsenal, and of course the rounds that go into an AR-15's magazine are of critical importance as well.

5.56 subsonic