BH's 77gr (.223) VS BH's MK262 (5.56)

[C4IGrant]

What's the difference between the two? Many have asked so I thought I would shoot some groups using each ammo.

I fired one group of 5rds @ 200yds using the BH blue box 77gr MK's (.223).

I fired two groups of 5rds @ 200yds using BH's MK262 MOD 1 (5.56).

The AR was zero'd at 50yds using the blue box 77gr ammo.


It is clear to me that the MK262 is ever so slightly hotter than the .223 77gr Mk's, but for the most part they are very even and both deliver fantastic accuracy.


http://www.gandrtactical.com/images/archive/JN%20Rifleworks/16N4BH77grvsmk262.jpg



C4

[threefeathers]

At 100 meters mine did the same thing. I'm going to chrono all of them later this Spring.

[Ned Christiansen]

Have had great results with both.

Actually it seems to me that the AR plays well with 75/77 grainers.

What was the twist on that gun? 1-9 is said to be marginal, I have not shot these with anything slower than 1-8. I found that in the Hornady line there was quite a difference in the bullets in their 5.56, FPD, and Match 75's. All shot well mind you but it made me wonder if one or the other would be more sensitive to 1-9 twist.

[jmart]

At 100 meters mine did the same thing. I'm going to chrono all of them later this Spring.

From your AT or something else?

[C4IGrant]

Have had great results with both.

Actually it seems to me that the AR plays well with 75/77 grainers.

What was the twist on that gun? 1-9 is said to be marginal, I have not shot these with anything slower than 1-8. I found that in the Hornady line there was quite a difference in the bullets in their 5.56, FPD, and Match 75's. All shot well mind you but it made me wonder if one or the other would be more sensitive to 1-9 twist.

Twist rate was 1/7 and was a new Noveske N4 middy.



C4

[Robb Jensen]

IIRC KevinB chrono'd MK262 Mod 1 and Black Hills red box 77gr and said that the MK262 was on average 100fps faster than the 77gr .223 Rem pressure load from BH.

[Razorhunter]

Thanks for this info Grant. Just what I've always wanted to know myself.
So, I suppose one could say that the .223 BH's is just about as good a self defense round as the Mk262?
A simple man like myself just wants to know what the most lethal, or best defensive ammo is for the M4 1/7 bbl?
I mean, I know that is a generalized question, but what do I want for a general purpose WAR FIGHTING round? I don't care about overpenetration, and I am not sure if I want a TAP round that is made to prevent overpenetration.
Rather, I would think a general purpose WAR FIGHTING round would strive for MAX PENETRATION, in case of car doors, glass/etc being in between my bullet and my enemy.
Not to mention the enemy possibly wearing body armor.
What round do I want? Do I still want TAP, or do I want 77SMK/Mk262 ammo?

[5pins]

Although it has not been maintained for some time the Ammo-Oracle will help.

http://www.ammo-oracle.com/body.htm

[jmart]

Rather, I would think a general purpose WAR FIGHTING round would strive for MAX PENETRATION, in case of car doors, glass/etc being in between my bullet and my enemy.
Not to mention the enemy possibly wearing body armor.
What round do I want? Do I still want TAP, or do I want 77SMK/Mk262 ammo?

For this, you want a 6.8 or a .308. No 5.56 OTM performs well against glass a sheetmetal, it doesn't matter if it's NATO pressure or regular TAP.

If tough intermediate barriers are your real concern, and you are committed to using a 5.56, then look at TBBC or Corbon DPX. They will penetrate barriers and hold together, but they won't frag in soft tissue like an OTM.

I don't think any of the 5.56 rounds will penetrate body armor.

[C4IGrant]

IIRC KevinB chrono'd MK262 Mod 1 and Black Hills red box 77gr and said that the MK262 was on average 100fps faster than the 77gr .223 Rem pressure load from BH.


That was my guestimate as well.


C4

[C4IGrant]

Thanks for this info Grant. Just what I've always wanted to know myself.
So, I suppose one could say that the .223 BH's is just about as good a self defense round as the Mk262?
A simple man like myself just wants to know what the most lethal, or best defensive ammo is for the M4 1/7 bbl?
I mean, I know that is a generalized question, but what do I want for a general purpose WAR FIGHTING round? I don't care about overpenetration, and I am not sure if I want a TAP round that is made to prevent overpenetration.
Rather, I would think a general purpose WAR FIGHTING round would strive for MAX PENETRATION, in case of car doors, glass/etc being in between my bullet and my enemy.
Not to mention the enemy possibly wearing body armor.
What round do I want? Do I still want TAP, or do I want 77SMK/Mk262 ammo?


TAP and 77gr BH's are both high quality, defensive rounds. Both will serve you well in some capacities. For going thru "things" I would look more to a .308.


C4

[John Fettes]

Is the same bullet used in both the Red Box ammo and the MK262?

John

[RAM Engineer]

IIRC, Red Box .223 uses SMKs without the cannelure, whereas the MK262 (Mod 1) uses SMKs WITH a cannelure.

[BushmasterFanBoy]

TAP and 77gr BH's are both high quality, defensive rounds. Both will serve you well in some capacities. For going thru "things" I would look more to a .308.


C4


C4

In the AR platform, you can always look to the bonded JSP loads. Decent expansion, but with incredibly high penetration/mass retention. If my goal was to use the 5.56 to go through things, I'd look at the Federal Tactical Bonded JSP ammo. It showed a pretty good ability to penetrate glass and retain mass.

[John Fettes]

Sierra sells the 77 w/cannelure now as a component.

http://www.sierrabullets.com/index.cfm?section=new_products&page=2008

John

[sinister]

At the US Army Marksmanship Unit we constantly seek to buy the best and biggest lots of accurate ammunition to flawlessly feed through approximately 200 competition (iron-sighted) rifles and uppers for the Army, Army Reserve, and Army National Guard Teams to (1) Win, and (2) Beat the Marines. ;)

The Unit first used Federal 69-grain Gold Medal Match, and it was unbeatable at 200 and 300 yards -- however the National Trophy Infantry Team Match, the "Rattle Battle," is a rapid-fire match shot at 600, 500, and 300 yards so we went to heavier bullets for the ability to buck wind and still shoot tight groups. Magazine-length 5.56mm ammo has to feed flawlessly while grouping in the middle of E-type silhouettes (since all shooters dial in to the squad leader's wind call -- for instance, "ALL SHOOTERS, 2 (clicks) RIGHT!" All shooters respond "2 CLICKS RIGHT" and put on the same correction, and everyone is "Dialled in"). 6-man teams are trying to kill 8 E-type slihouette targets exposed for 50 seconds at each yard line. Targets hit at the farther yard lines (600 and 500 yards) are worth more points. A "Swing" shooter (one of the guys on the end) can fire 40 rounds between two magazines at the two end silhouettes in 50 seconds at 600 and 500 yards.

We shot 73s, 75s, and 77s. 73s shot the best, but at the time Walt Berger was retiring and selling his Berger bullet company so there was no guarantee we would have future supply. 77s outshot 75s so that was the default choice.

69s outshot 77s at 200 and 300 yards.

9-11 happened and we loaded pallets of competition ammo on trucks for the United States Army Special Operations Command, bound for war.

Trying to plan for the worst possible scenario some users specified their 77s had to have waterproof necks and cannelured bullets. Sierra doesn't actually put in a deep cannelure, but shallow "Crenellation" marks (Like the edge of a dime or quarter). This may detract from accuracy.

AMU 77s rely on neck tension vice crimping to properly align and hold the bullet coaxially within the bore.

The AMU accuracy standard is to fire at least five 10-shot groups from a machine-rested M16. All groups must go into smaller than 3.25 inches at 300 Meters. If we're testing the rifle and it can't do that it goes back to the shop. If ammo won't do that from a bolt-action test gun we won't buy or accept that lot. "Flyers" mean "I lose" one the range or "I missed and didn't kill him" on the battlefield.

The Army Rifle Team's "Secret Loads" (as of about three years ago, and I ain't telling what they are) are called "Option A" and "Option B."

You heard it here first.

[John Fettes]

Thanks to sinister for the education.

I have only seen pictures of the 77 SMK on the Web, and the cannelure is faint compared to that seen on the 55's.

Grant's comment in re the .308: I remember many years ago Ken Hackathorn wrote that if you wanted to shoot at people in cars, you needed something with a 30 in it, as in .308 or 30-06. The .223/5.56 options for both guns & ammunition then were very limited by today's standards.

John

[5pins]

The Army Rifle Team's "Secret Loads" (as of about three years ago, and I ain't telling what they are) are called "Option A" and "Option B."




You can tell us. We won’t tell anyone. You know keeping secrets is bad for your health. Consider it therapy.

[Face_N_The_Crowd]

Is it possible for a handloader to replicate MK262 loads? I have a fuzzy understanding that we can not b/c of our powder options.

My current load is 24.2 of RE15 and 77 SMKs with a regular (non mag) small primer.

[John Fettes]

In addition to the powder problem, I don't know if the exact same bullet used in the MK262 is available commercially. Maybe someone here can tell us.

That being said, I suspect that if you do load development, you can come close. You might do some searching on the AR15 forum & here got more info.

John

[sinister]

Mark 262 powder is canister grade and not commercially available.

Your best results from home-brews would be to use a tight neck-size bushing (instead of crimping) and use a high-energy double-base powder like VihtaVuori 540.

[platinumdude]

Thanks for this info Grant. Just what I've always wanted to know myself.
So, I suppose one could say that the .223 BH's is just about as good a self defense round as the Mk262?
A simple man like myself just wants to know what the most lethal, or best defensive ammo is for the M4 1/7 bbl?
I mean, I know that is a generalized question, but what do I want for a general purpose WAR FIGHTING round? I don't care about overpenetration, and I am not sure if I want a TAP round that is made to prevent overpenetration.
Rather, I would think a general purpose WAR FIGHTING round would strive for MAX PENETRATION, in case of car doors, glass/etc being in between my bullet and my enemy.
Not to mention the enemy possibly wearing body armor.
What round do I want? Do I still want TAP, or do I want 77SMK/Mk262 ammo?


With regards to car doors and windshields, have you seen this site?

http://www.theboxotruth.com/docs/thebuickotruth.htm

Edit, this one on level IIIA body armor:

http://www.theboxotruth.com/docs/bot16.htm

[threefeathers]

I'll use my A T, a Colt HBAR, and an M-4 carbine with SOCOM Barrel.
This will be an all day thing so I have to plan for it.
I'm just a reloading nut who happened to make it to the All Army matches as a competator in either rifle or light machinegun 9 times. (As I type I look to my left of a pic of me running the 2 mile course and am passing the water tower, was I ever in that shape)
If someone challenges me to make a bullet that is the same as something I'm going to figure out how to do it. (I was also raised in the Black Hills cause my father was a patient at the Battle Mountain VA) Must be something in the blood there that makes folks load bullets. (I learned to spell in the red schoolhouse in Hot Springs)
I called Nosler and got 5K of their cannelured 77 grain pills. Then a bunch of never fired Lake City brass and finally a whole bunch of Lapua brass from Bruno.
I used 6 powders and agree that the best is V540, although RE15, Varget, and TAC come close.

A Cavaet, the 77 grain is good, but I also got a bunch of Berger 73 grain bullets I crimped them with the Lee Fac Crimp and they are the most accurate load I have from any rifle. But ya gotta be willing to pay bucks and the difference might not be worth it.

Right now personally I'm more interested in 30 Cal for my Springfields.