BH 77gr - .223 vs 5.56 for HD

[brzusa.1911]

I did try searching, either I didn't search well enough or there were no discussion on application for HD. I did find a thread started by Grant comparing these two on accuracy, I would like to know what you think in terms of ballistics for CQB HD.

[Submariner]

Have you read 5.56 mm Duty Loads?

Only after proper foundational and ongoing repetitive refresher training, cultivating warrior mind-set, and ensuring weapon system reliability do you need to worry about ammunition selection. Most folks would be far better off practicing with what they have, rather than worrying about what is "best". As long as you know your what your weapon and ammo can realistically accomplish, it is all just a matter of training and shot placement. I would much rather go into battle with a guy who practices 15,000 rounds a year using generic 55 gr FMJ out of his old M16A1 than with some guy that has the latest state-of-the-art ammo and rifle, but only shoots 500 rounds a year. ...

Absent gel shots from DocGKR, searching Molon's postings might be helpful. I sought similar information, specifically regarding fragmentation ranges. Unable to find it after an extensive search of his postings, I emailed Molon and got this:

Re: Fragmentation Range for Mk 262 Mod 1

Unfortunately, I'm not a big fan of MK262, so I haven't devoted a lot of time to studying it. While it is certainly far more accurate than M855, it is not nearly as accurate as people on this site claim it is (although 223 pressure loads with the 77 SMK can be.) Also, due to its longer and more variable "ballistic neck," it does not have as good as terminal ballistic properties as other bullets in the same category (Nosler 77 grain BTHP, Hornady grain 75 BTHP.)

Since the 77 SMK has a thicker jacket than the two previously mentioned bullets, one would expect that it has a higher fragmentation threshold and therefore shorter fragmentation range, although I haven't verified this, so it is merely speculation. As I recall, there are those who claim that the fragmentation threshold is 2300 FPS, but again I haven't verified this myself. If that is true (and not taking into account other variables) one could expect MK262 to have a fragmentation range of approximately 40 yards less than 5.56 TAP; again just speculation. Sorry I don't have a specific answer for you.

Cheers,

Molon

Molob's only chart I found which directly compared 5.56mm BH and .223 BH was this:



Do you already have BH and are trying to justify your selection? I was.

Now I buy TAP 2. After sustainment training and practice. When I can find it.

[Alaskapopo]

Well I selected 75 grain Tap as our duty load based in part on Dr. Roberts opinion and it has worked well for us. Have not had to shoot any people but we have had to use them to kill black bear. (one 190 pounder and 160 pounder). While its certainly not the best tool for bear they did the job with proper shot placement.
Pat

[Nemecsek]

For HD, it shouldn't matter. On a side note, I have found that .223 BH 77gr is the most accurate (.75MOA), followed by M262 (1-1.25MOA) and lastly T2 TAP 75, which is barely 1.5 MOA from my Noveske 18".