AKM: 5.45x39, 556x45 or 7.62x39?

[Beiruty]

Intent of use:
1) 3 Guns matches
2) Lowest cost for the ammo.
3) Availability of the ammo.
4) the more accuracy the better.

I can discount the 7.62x39 and I am not sure if I go with the Russian 5.45 or NATO 5.56?

[The Annoyed Man]

Intent of use:
1) 3 Guns matches
2) Lowest cost for the ammo.
3) Availability of the ammo.
4) the more accuracy the better.

I can discount the 7.62x39 and I am not sure if I go with the Russian 5.45 or NATO 5.56?

That's a tough one....

The problem is the inherent accuracy of the AK platform in pretty much all of its variants is not as high as the AR and other small caliber battle rifle platforms, regardless of whether you're talking about the 7.62, or the 5.45 or 5.56 variants. It is probably a more reliable weapon than the others, but the things that contribute to its reliability are the same things that subtract from its accuracy.

So, what is the longest range we're talking about? If you're shooting at 8" plates at 100 yards, under the pressures of competition, from a 4 MOA rifle, you're chances of missing shots are fairly high - at least too high for competition purposes. If that is the case, then I don't know if the 5.56 cartridge is inherently any more accurate than the 5.45 cartridge; but I have yet to see a truly accurate rifle chambered in 7.62x39. So I would stick with the smaller calibers for that. If the rangers are mostly shorter than that, then I would guess that caliber is a non-issue, so make your selection based on other factors.

Accuracy aside, the terminal ballistics in 5.56 out of an M4 barrel are roughly the same as the 5.45 out of the AK barrel, so that is a non-factor. The 5.56 used to be better, but it was being fired from longer barreled M16s back then. Shorter barrel = less velocity, bringing it into the same area as the 5.45. If the ballistics are important to the sanctioning body, I don't think there's any advantage for either of the smaller cartridges over the other.

If this is for competition use primarily, I'd go with the 5.45 for three reasons: A) it is probably cheaper than both the 7.62x39 and the 5.56x45; B) it is probably more available than the 5.56x45; and C) it probably has a lower recoil impulse than the 7.62x39, making it less fatiguing to shoot over the long haul. On the other hand, if it were a rifle meant primarily for TEOTWAWKI, I'd go with the 7.62x39 round which I believe to be more plentiful overall than either of the other two calibers, and which I believe is also a more versatile round for battle/hunting/plinking. To my mind, .30 caliber bullets usually beat .22 caliber bullets, for much the same reason that my carry pistols are .45s instead 9mms. And by the way, Mikail Kalashnikov is on video record as scorning the 5.45 cartridge, insisting that the only reason the Soviets developed the cartridge was that NATO had a .22, and they thought the USSR should "keep up with the Joneses." He was of the opinion that the 7.62x39 cartridge was the superior cartridge.

OTH, for your competition uses, I'd have gone with an AR15 in the first place. But that's just me.

[Beiruty]

Thank you TAM,
If I go with with AR derivative, I would prefer a piston driven and my choices
1) FN SCAR 16S,cool side folding stock. Too expensive
2) HK 416: TOO expensive too.
3) SIG 556 SWAT Patrol, around $1200

[bnc]

I'm not sure about the accuracy of most of these guns, but have you considered at pistol caliber carbine? There is a 9mm Beretta CX4 in the forsale subforum, looks like a neat gun (but I don't know much about them).

[RECIT]

So your mind is made up on the AKM platform? If so I would go with the 5.45 round over the 7.62x39. The 5.45 will be more accurate with less bullet drop at distance and recoil less making follow up shots quicker in competition. The ammo in either 7.62x39 or 5.45 is dirt cheap. The 7.62 is available in many brands and many flavors of bullet type and weight. The 5.45 round is available in Russian surplus which is corrosive and needs an extra cleaning step after every range session or you can buy Silver Bear and Wolf. Neither are known for their accuracy. There is no match or HIGH quality name brand ammo available as of now.

I think the 5.56 mags for an AK if you were able to find would be a deal breaker as far as cost were concerned. I like the AKM and the 5.45 cartridge, but I don't know if its best suited for 3-gun. It just seems like the AR platform lends itself to competition more naturally.

[The Annoyed Man]

Thank you TAM,
If I go with with AR derivative, I would prefer a piston driven...

Beiruty, I think I understand why you prefer that, but I'm not convinced that it is worth the additional expense. I've never had difficulty keeping my ARs clean, and I've never had a malfunction attributable to accumulated grime. My guess is that you'll require the same amount of lube, whether gas-piston or gas-impingement cycled. And I own a gas-piston rifle: my M1A. It gets just as dirty as any other semi-automatic battle rifle when you run a lot of rounds through it. And a gas piston is just one more part that needs to be cleaned/lubed periodically.

Or maybe I'm just being a luddite....

[RECIT]

Piston AR's run quite a bit cooler too.

[Beiruty]

One thing, that I find not solved on the AK platform, even on the latest Russian RIfles, is the lack of lack of bolt catcher/release.

[RECIT]

One thing, that I find not solved on the AK platform, even on the latest Russian RIfles, is the lack of lack of bolt catcher/release.

It is not designed to have one...why do you NEED one anyway. I always do a visual check whenever I pick any weapon.

[RECIT]

After very short research session I found that Yugo AK safety selectors have a bolt hold open notch machined into the safety lever. Its not a last round open bolt design but will HOLD the bolt open if you engage the safety lever. Also found that certain Yugo mags have a different follower that will hold the bolt open on the last round, but if you pull the mag then the bolt will close.

[jeeperbryan]

One thing, that I find not solved on the AK platform, even on the latest Russian RIfles, is the lack of lack of bolt catcher/release.

It is not designed to have one...why do you NEED one anyway. I always do a visual check whenever I pick any weapon.

Agreed, not really needed.

[The Annoyed Man]

Piston AR's run quite a bit cooler too.

So how come AKs can set the furniture on fire?

[RECIT]

Piston AR's run quite a bit cooler too.

So how come AKs can set the furniture on fire?

Piston AR's run cooler than a direct impingement AR's. I guess I should have been more clear.

[PeteCamp]

Piston AR's run quite a bit cooler too.

So how come AKs can set the furniture on fire?

Piston AR's run cooler than a direct impingement AR's. I guess I should have been more clear.

Think carefully about what you just said though. You are firing the exact same cartridge out of two weapons. The combustion of the round generates the only significant heat - right? No matter if it is a bolt action, piston or gas-impingement, the exact SAME AMOUNT of heat must be dealt with by the rifle. In truth, all the piston does is change the LOCATION of the heat.

TAM is correct. Go shoot a PISTON system - an AK-47 - and see if it doesn't get hot. Then go do the same thing with a piston AR and see if it doesn't also get hot. Then shoot a gas AR and see if it gets hot. Secret clue: They will all be hot. The only difference is WHAT gets hot.

Don't believe all the media-hype garbage people put out about pistons. They are mainly a way to get some more of your money that you don't really have to spend. There are some advantages (and some significant disadvantages) to piston systems in full auto fire. If you'll be doing a lot of that, well then, I might consider the extra expense. Otherwise, IMHO, save your money.

[RECIT]

Piston AR's run quite a bit cooler too.

So how come AKs can set the furniture on fire?

Piston AR's run cooler than a direct impingement AR's. I guess I should have been more clear.

Think carefully about what you just said though. You are firing the exact same cartridge out of two weapons. The combustion of the round generates the only significant heat - right? No matter if it is a bolt action, piston or gas-impingement, the exact SAME AMOUNT of heat must be dealt with by the rifle. In truth, all the piston does is change the LOCATION of the heat.

TAM is correct. Go shoot a PISTON system - an AK-47 - and see if it doesn't get hot. Then go do the same thing with a piston AR and see if it doesn't also get hot. Then shoot a gas AR and see if it gets hot. Secret clue: They will all be hot. The only difference is WHAT gets hot.

Don't believe all the media-hype garbage people put out about pistons. They are mainly a way to get some more of your money that you don't really have to spend. There are some advantages (and some significant disadvantages) to piston systems in full auto fire. If you'll be doing a lot of that, well then, I might consider the extra expense. Otherwise, IMHO, save your money.

I have an AK, several AR's and have shot a few piston AR's...yes the AK gets HOT. Yes the Piston AR's got hot, but not nearly as hot as the direct impingement AR with about the same amount of rounds down range in the about the same amount of time. I think the impingement system circulates more of the hot gas through more of the gun, intern making the gun run hotter to the touch than a piston AR in my opinion. YMMV. To revert back to the OP question I doubt it would matter which style he wants b/c in a 3 gun match it won't get hot enough to matter.