I recently learned that the current 5.56 NATO ammunition performs at its best at or near 200 yards.  This goes for wound cavity and penetration.  Anything closer and the bullet comes apart quicker and anything further away and the kinetic energy dissipates quickly.  Don't ask me where I read that I can't for the life of me remember.  Armed with that information I'm now trying to find the same information for the 7.62 NATO (and also out of curiosity the 7.62x39 Soviet and 7.62x54R Russian).

Anyone know in particular at what range the 7.62 NATO is "most effective" in terms of penetration and wound cavity production?  Me thinks it has to be a bit further out than 200 yards simply due to bullet size and construction.  

Makes no sense to me.

You don't speak English? Shall I try pig latin?    

Ok... let me try again: At X distance the 7.62 NATO will penetrate best because of the ratio of velocity and bullet construction is at nirvana and the projectile will penetrate best through a medium thicker than air.  What distance is X ?  

I don't believe that's correct re: 5.56.

Penetrate what? A deer? Armor plate? Masonry? It seems to penetrate haji's just fine out to 1,000 yds.

What your saying about 5.56 depend on the barrel length and bullet type. 193 vs 855. 200-250 yards might be about right for a M4 length weapon.
7.62 nato is about 800 meters max on a human target. This also depends on barrel length. 1000 yards is obtainable with a 24-26 in weapon.

There is a ton of info out there with regards to ballistics of both .223/.556 and .308

Blackhills (Mk262 mod11) has put some baddies down at more than 200yds.

For .308 flavor, TAP 110 for closer in and their 155 has great ballistics. As a general rule 168gr with run you out to roughly 600yds with 175gr pushing a bit futher.

At 600yds a 168gr Fed match in running aprx. 1600fps with around a 1000 ft lbs of energy.  

But there is so much more to the picture that's not here. Are you anticipating shooting through glass, doors or other mediums? What are you using it for hunting? What is the barrel length, etc.

I'm not asking about anything other than the standard 7.62 NATO fired from a 18-20in barrel (M14, FAL, G3, or MG, etc).  Somewhere out in cyber space there is a write up or a chart of the testing that was done on the standard 7.62 NATO and at what range the projectile penetrated best.

The 5.56 NATO (both 62gr and 55gr), fired from the 20in barrel out of an M16A2 performed their best at or near 200 yards.  At that range the combination of kinetic energy and the ability of the bullet to hold together upon impact deliver optimum bullet performance.  At closer ranges the bullet fragments much easier and anything further out the kinetic energy is quickly being lost.  The optimum range It is going to be closer if the rifle is an M4, the 250 fps less velocity it produces is going to bring that range in a bit closer, but I do not remember reading anything about the 14.5in barrel, only the 20in.

I sort of figured this was common knowledge amongst these forums, I guess not.  But now it is known by at least some.    I was thinking that someone may have the same bit of info for the 7.62 NATO.  I'll keep diggin'.

You realize you want the bullet to break up don't you?  M193 and m855 tend to ice pick if they don't break up.  That yaw and temp cavity don't really do a whole lot of damage.   Pure kinetic energy does nothing to a target unless the energy is turned into damage.  Using that energy to create a big temp cavity doesn't do much if muscle and organs Arn't lacerated and bones broke.  As in, m995 having lots of kenetic energy but at close range they zip through with little major wounding.

Besides, you should be using mk262, tap T2, TSX, or bonded barrier rounds.  Your numbers don't apply using those bullets.

You gonna make sure any engagements only happen at 200 yards?  

I really wish DrGKR posted more so he could come in here and set you straight.

Your wrong. You really don't want m193 or m855 to hold up.

Your also using penetration wrong.  Penetration up to a point is good. Past 18 inches it's a liability.  

It's also gonna irk a lot of guys that you're using penetration in this manner. Penetration of what? Horses or cinder blocks? Trees or Hajis?

Again I say, knowing what's optimal is a silly question, in the real world your not going to be able to dictate the range.

Typical muzzle velocity for 147gr FMJ is 2750fps. It should hold up fairly well at 50yds and still has 1000 ft/lbs of energy at 500yds, so pick any range in between.

Yep, don't over-think this stuff.

But for some certain things, 7.62x54R is an excellent choice.

Most effective for humans=fragmentation to destroy as much CNS as possible. The m193 does it better than m855 and you can read all about that in the ammo oracle.



The only 7.62 nato that frags it metal jacket stuff, more common from imports/europe. Just like the 5.56 its velocity dependent, around 2008'/sec, so yuo wont get it to frag form shorter barrels. Saying that get 155 amax if you want max frag.

As long as bullet penetrates 12 plus inches it's good to go. You want that little rice grain to blow up inside a target or it won’t reliably stop a threat. Look up the tnoutdoors9 on youtube he does some great ballistic test with 5.56.
You are stuck on just one aspect of wounding ballistics; there is more to it than just penetration.
As far as 7.62 goes that sucker won't blowup like 5.56 will. 7.62 will start to tumble inside a soft target and penetrate deeper than 5.56 because it's a heavier projectile.

I asked a simple question about optimum penetration values of the 7.62 NATO and I'm getting lectured on wound cavities, 5.56 NATO's reliance of fragmenting, velocities at X range, and hypothetical "can do" capabilities of the round in question. I appreciate the attempts, but in the spirit of Stifler's closet encounter in American Pie III, "Focus, focus, focus!"  

What I saw with the 5.56 NATO was showing ranges of 50 to 400 yards at intervals of 50 yards.  The mediums were masonry block, steel plate (3/8th?), wood planks, and ballistic gelatin.  The findings on the "penetration" abilities were consistently showing at or near 200 yards to be the optimum range for the 5.56 NATO to penetrate.  Anything closer and the bullet fragmented too easily and anything further away and the kinetic energy was on the down hill swing.  There is a correlation between bullet construction and velocity that allows 200 yards to be "it" for the two different 5.56 NATO rounds.  The author referenced his findings and that of the US Army's findings to be very similar.  I have not searched any of the official US Army's research archive *yet*.  But I will.    

I'll keep searching on in the interwebs and post the info when I find it. Somewhere out there is the info for the 7.62 NATO's optimum penetration range in data form.  Like I said, I figured someone here would have some insight on similar info for the 7.62 NATO.

EDIT: This is NOT the exact source I had seen early, but it does reference the 200m range as being the "best" range for penetration purposes. Scroll down to "ammunition effects". 200m is optimum range

EDIT #2: Not surprisingly I found similar info on the 7.62 NATO on the same sight as linked above.  I was a bit surprised at 600m being the "optimum" range of penetration though, I'd figured it would be between 300-400m. 600m is optimum?

That's alot of words to simply ignore what everyone has been saying this whole thread: optimum is where the target is...

1. link is bad
2. So I need to back out to 600m to best penetration?? I think i will pass
The reason you got the replies you did is because you are not being very specific.
"penetration" has a lot of variables depending on medium, which you left open ended. Which is more important, wounding or penetration, that will affect the range estimate even more. This all assumes you take good shot placemen to start with



 

Optimum is where the best results are obtained due to X and Y factors.  At ranges of 100 yards the projectile performs differently than at ranges of 400 yards due to those X and Y factors I've mentioned.  Optimum is where the X and Y are symbiotic, meaning the bullet composition is strong enough to maximize the amount of kinetic energy.  Too close and the bullet cant stay together, too far and there is a lack of velocity.  Is it really that difficult of a concept to grasp?  

Your "optimum is where the target is" is a bit simplistic and completely not what I was interested in.  But thanks for trying.  I found what I was looking for.  

Carry on.

1. link is good.  I just clicked on your quote and it went fine for me.
2. The 600m doesn't mean it is not effective at other ranges, it simply means at that range the velocity and bullet composition are paired well enough for maximum penetration.  I'm not exactly sure vs what medium though, I'm betting something other than armor plate.  More research needed on my part.

Longest 7.62 nato kill in Iraq is 1312 yards, So I would have to say it is effective up to 1312 yards.

what in the world are you going on about? Optimum in what?
Please answer this question.
You got every one confused as hell.


Why dont you want the bullet to break up?

Here is a quote from the nonsesnce that he's talking about

5.56 mm Maximum Penetration. For the 5.56mm round, maximum penetration occurs at 200 meters. At ranges less then 25 meters, penetration is greatly reduced. At 10 meters, penetration by the 5.56mm round is poor due to the tremendous stress placed on this high-speed round, which causes it to yaw upon striking a target. Stress causes the projectile to break up, and the resulting fragments are often too small to penetrate.

and this is nonsense because why?

Here is why, xm193 going through 18 inches of gel at 50 yards and it did tumble mind you. Are you looking for more?
Watch the video http://www.youtube.com/watch?v=SPzxBJSIaGA
The paragraph that I quoted is vague and has very little substance, just like the entire web page. You need to be more specific, maximum penetration is a loose term in that context.
Edit: here is from 20 feet
http://www.youtube.com/watch?v=RZPGSiDs5_k

Use a barrier blind round and then shoot at what ever distance you want if cover penetration is what you are worried about.

There is no hard and fast rule for this beacuse NATO 7.62x51 ended up being a general rule, while 5.56x45 ended up being a true standard. NATO 7.62 ball ammo was available with bullets ranging from 145 to 150 grains, depending on what nation produced it. The construction of the bullet wasn't standardized and some rounds fragmented very well, and some had almost no fragmentation.