Advantages of the 5.56x45 over 5.45x39

[Snowdog]

No, this isn't a statement, but a question only.

A couple days ago, a friend and I were discussing the fine points of these two cartridges and how they stack up to eachother.

I made the comment that the new M855/SS109 seriously closes the gap in bullet weight between the two.

Any contributions? I think fresh ammo on the subject might stimulate debate the next time we meet.

 

[Art Eatman]

Ain't it an eternal verity that a longer case holds more powder and thus gives more velocity? I grant that there can be an efficiency issue, but if one defines "better" as more velocity for a given bullet weight, or as equal velocity for a heavier bullet...

, Art

 

[Dave Markowitz]

If looking at these for their intended use -- military rounds -- I give the edge to the 5.56x45. It has greater case capacity and better external ballistics. Also, when loaded with M193 Ball, the terminal effects are much more impressive. From what I've seen the M855 gives better penetration but it's wounding potential, especially from short barrels, isn't as good as the older round.

Note that I don't prefer the 5.56mm because of the fact that it's American -- I think the 7.62x39 makes a better military rifle cartridge.

 

[Erich]

I agree with my man, frodo. Of course, there's also the clear logistics advantage of the NATO round . . .

 

[boing]

If you want to hurt bad guys, my understanding is that the Commie bullet is constructed in such a way as to be much less velocity dependant than the Yankee round. Something about hollow a cavity with a lead slug inside it that shifts on impact and initiates tumbling more readily.

Speaking from a tissue damage stand point, only. What's good against people isn't always the same as what's good against material. Seems the newer, heavier 5.56 rounds are more about poking holes than big wound channels.

 

[MiniZ]

I don't want to get shot with either one....

I have both in my collection, and really like them both.

I guess if I wanted to delve into ballistic coeficients, etc., I could formulate an opinion of which is "better", but for my purposes, both suit me just fine.

 

[Zorro]

5.45x39.

It is designed to fire a heavier bullet.

Just finished firing some, 71 Grains each.

Better BC too.

 

[Dave R]

I can think of one advantage the 5.45X39 has. Its cheaper most places. Not enough of an advantage for me. I got my AK in 5.56X45./ .223

 

[Drue]

The .223 and the 5.45x39 are very similar in that they are designed to bring lightweight ammo and controllability in FA fire to military rifles. Both are effective in the military role. I agree with boing that the 5.45 is less velocity dependent for wounding ability. Once the .223 drops below the fragmentation threshold it tends to make ice pick like wounds. The long 5.45 will tumble at much lower velocities.

The original M193 ball ammo for the .223 shoots a 55gr bullet at 3250fps and the current M885 shoots a 62gr bullet at about 3000. The Russian 5.45mm ball shoots a 59gr bullet at 2950. The .223 is more powerful but the 5.45 is close and it works for the Russians. I have read that the Russians consider the 5.45 effective to 400M vs 300 for the 7.62x39.

I have an AK-74 clone built from a K-Var kit on a Saiga receiver. It's fun to shoot. The '74 muzzle brake seems to reduce the already light recoil but increases the noise. I don't notice much difference between the 74's recoil and an AR-15.

For us here in the US, the quality, availability, reloadability and variety of ammo are heavily in favor of the .223. The Russian 5.45 ammo available here is cheap and it works but that is about all that can be said about it. .223 is available in military configuration, commercial ammo is available anywhere that ammo is sold, and match ammo is available. Reloading components, including cheap, once fired, USGI brass are widely available. Reloading the steel 5.45 cases is not really practical. Cases can be made from .222 brass but it is an involved process and bullets in the 5.45 diameter are not available. .224 dia bullets can be swaged down but this is another involved process. I like wacky reloading projects as much as anyone else but with Russian ammo at 0.12/round it hardly seems worth it.

From the point of view of the recreational shooter, the .223 is much more flexible and easier to manage. From the survival point of view, the AK-74 is a formidable weapon but don't look for much variety in ammo and don't count on any resupply.


My 0.02

Drue

 

[BigG]

What diameter bullets are used to reload the Commie round?

 

[Drue]

Ijust miked a Barnaul 59gr FMJ. It read .220.

Drue