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Posted: 12/28/2005 2:06:43 AM EDT
For those of you who have experience with both the AR and Ak-74 type rifles, how do 5.45 and 5.56 compare? I know this may be an old topic, so if any of you have a link to a previous thread that would be great (did a search but got zero returns). Thx
Link Posted: 12/28/2005 4:02:13 AM EDT
[Last Edit: 12/28/2005 4:19:13 AM EDT by ABNAK]
Alexander Arms makes (or used to make?) a 16" AR upper in 5.45x39. It is/was called the ".221 Genghis". While this may not answer your question about comparison, it shows that it's possible to have both on the same platform.

You must consider, though, that the amount of fouling from firing 5.45 Wolf in a direct impingement weapon is probably excessive.

5.45 was the Soviet's attempt at duplicating our "small caliber high velocity" 5.56mm concept. It originally launched a 52gr bullet at @ 2900fps. Remember that this round was DESIGNED to be fired from the 16" barrel of the AK-74, not for a 20" barrel and later used extensively out of shorter ones (like the 5.56 has been). It has an air pocket in the nose that is filled with a "plug" from the rear when it hits a target, causing it to become unstable and tumble (yaw) more quickly than other rounds. The 5.45 does not rely on fragmentation to cause damage like the 5.56 does. Instead it relies on the tumbling effect for damage. One thing about tumbling is that it is not as velocity dependant for success like fragmentation is; hence it will perform as designed at lower velocities, more so than a 5.56 will fragment at lower velocities. There is a debate about whether tumbling is as effective as fragmentation for "stopping power", so opinions abound.

5.45 is a relatively flat shooting round like the 5.56, but I do believe the latter has the edge in accuracy.

It also has a very slight taper to the cartridge (like the 7.62x39) that aids in extraction under adverse conditions.

Link Posted: 12/28/2005 8:40:45 AM EDT
Why not manufacture 5.56 bullets with a hollow internal cavity to perform the same as the 5.45 in terms of balistics? Considering the 5.56 relies mostly on velocity which limits it's capabilities to under 300 meters then using the Russian technology of a hollow cavity with lead plug to slam foward causing the yaw effect upon impact then the technology could extend the killing range of the 5.56 with the accuracy of the 5.56. However overall I believe these two rounds to be within a 100FPS of one another with similiar accuracy.
Link Posted: 12/28/2005 8:59:42 AM EDT

Originally Posted By Creeper:
Why not manufacture 5.56 bullets with a hollow internal cavity to perform the same as the 5.45 in terms of balistics?



Because the 5.56 has better terminal ballistics? I'd much rather have a 75gr OTM than ANY 5.45 round. Because even outside of the fragmentation envelope it still yaws (like the 5.45) only it's yawing with a larger bullet...
Link Posted: 12/28/2005 9:43:13 AM EDT
Well then make the 75 grainer with a hollow internal cavity. The reason you need a 75 grainer is for distances outside the 300 meter effective 5.56zone, the extra weight does the killing, so with all things being the same then designing the bullet around yaw wounding capability which is not velocity specific as standard production 5.56.

Basically the 5.56 relies heavily on a velocity threashold that once lost the round quickly becomes insufficient for longer distance target engagement. Simply by designing the same round with a hollow internal cavity then it would matter if the velocity dropped below the threshold because the terminal wounding capabilities would be independent of velocity. Thus making a more effective round with existing design. Just my .02,

Creeper
Link Posted: 12/28/2005 9:48:56 AM EDT
[Last Edit: 12/28/2005 9:49:25 AM EDT by Forest]

Originally Posted By Creeper:
Well then make the 75 grainer with a hollow internal cavity.


Son are you "stuck on stupid"?


The reason you need a 75 grainer is for distances outside the 300 meter effective 5.56zone, the extra weight does the killing,

I suggest going back and doing some 'learing'

Weight doesn't kill nor does 'energy'.

It does it's job because it fragments like an SOB tearing nice 5" cavities into the goblins.


Basically the 5.56 relies heavily on a velocity threashold that once lost the round quickly becomes insufficient for longer distance target engagement. Simply by designing the same round with a hollow internal cavity then it would matter if the velocity dropped below the threshold because the terminal wounding capabilities would be independent of velocity.

Like I said I suggest you go and do some learning - start with the The Ammo Oracle then procede to the papers by Dr Martin Fackler that have been thoughtfully tacked at the top of the Ammo forum.

Then we can have a nice meaningful and informed discussion on your 'idea' .
Link Posted: 12/28/2005 10:18:40 AM EDT
[Last Edit: 12/28/2005 10:20:57 AM EDT by Creeper]
Mass x Velocity = energy transferred. Lower energy transfer for lighter weighted bullets with drop in veloctity thus a 75gr? For distance since most applications would be on an SPR type platform and the heavier weighted bullets carry retained energy over a longer distance to make up for the loss in the velocity threshold outside of 300 meters on the same platform with standard 62gr. My point is simple, if the russians designed a round that is independent of velocity and can produce similiar wounding capability to greater distances because it is independent of velocity then perhaps it is something worth taking a look at to incorporate into 5.56 rounds which overall lose capability under certain velocity.

Stuck on stupid? Well you tell me, since clearly 5.56 effective killing ranges are limited on velocity when the Russians designed similiar weighted rounds that are independent of velocity and have longer killing distance ranges. Basically our designed rounds are nothing much more than .22's under that magic velocity needed for explosive expansion, something that the Russian's figured out long ago with a simple hollow internal cavity with a lead plug in the rear that upon impact the lead slams foward, causing the jacket to expand, and the round to tumble. Simple, effective, and independent of magical velocity or weight thresholds.

Thinking outside the box even for a moment is sometimes OK.

Creeper
Link Posted: 12/28/2005 10:40:29 AM EDT

Originally Posted By Creeper:
Mass x Velocity = energy transferred.

Creeperhug.gif



Um, seriously no.
Mass x (change in)Velocity = momentum transfered
1/2 Mass x Velocity Squared = energy transfered.
Link Posted: 12/28/2005 10:49:24 AM EDT
I bet everyone in the military really cares what the "ammo-oracle" states.
Link Posted: 12/28/2005 11:36:27 AM EDT
if (distance > 300) * too many enemy contacts =
Anything else break out the
Link Posted: 12/28/2005 11:42:39 AM EDT
my ak's shoot 7.62x39
Link Posted: 12/28/2005 12:17:03 PM EDT

Originally Posted By No1Here:
I bet everyone in the military really cares what the "ammo-oracle" states.



They must because they paid for the research that is often quoted in the oracle...

The oracle was built because too many are just too lazy to go and look up the facts, not for the military's use.
Link Posted: 12/28/2005 12:29:37 PM EDT
[Last Edit: 12/28/2005 12:33:13 PM EDT by Hoppy8420]

Originally Posted By Creeper:
Mass x Velocity = energy transferred. Lower energy transfer for lighter weighted bullets with drop in veloctity thus a 75gr? For distance since most applications would be on an SPR type platform and the heavier weighted bullets carry retained energy over a longer distance to make up for the loss in the velocity threshold outside of 300 meters on the same platform with standard 62gr. It doesn't have to do with "Energy transfer", the heavier 5.56 projectiles fragment at lower velocities, and more reliably.My point is simple, if the russians designed a round that is independent of velocity and can produce similiar wounding capability No it doesn't. The 5.45 soviet round tumbles opening up two cavities roughly the size of the bullet itself. When a 5.56 round fragments, the cavity is much larger.]to greater distances because it is independent of velocity then perhaps it is something worth taking a look at to incorporate into 5.56 rounds which overall lose capability under certain velocity.

Stuck on stupid? Well you tell me, since clearly 5.56 effective killing ranges are limited on velocity when the Russians designed similiar weighted rounds that are independent of velocity and have longer killing distance ranges. After a 5.56 round drops below the fragmentation velocity it preforms much like the soviet round anyways. Basically our designed rounds are nothing much more than .22's under that magic velocity needed for explosive expansion, something that the Russian's figured out long ago with a simple hollow internal cavity with a lead plug in the rear that upon impact the lead slams foward, causing the jacket to expand, and the round to tumble. That is not what the projectile does. The lead doesn't slam forward. The air pocket and lead/steel core doesn't make the jacket expand. It moves the center of gravity rearward making the bullet more unstable in flesh. Simple, effective, and independent of magical velocity or weight thresholds.

Thinking outside the box even for a moment is sometimes OK.
Creeper

Link Posted: 12/28/2005 12:38:53 PM EDT
Originally Posted By FL-AR15:
if (distance > 300) * too many enemy contacts =
Anything else break out the

=======================================

+1

best. answer. ever.
Link Posted: 12/28/2005 12:39:43 PM EDT
so do mine and if you look at them they are bigger than the 5.56 or .223.
Link Posted: 12/28/2005 12:41:19 PM EDT

Originally Posted By mco119:
For those of you who have experience with both the AR and Ak-74 type rifles, how do 5.45 and 5.56 compare? I know this may be an old topic, so if any of you have a link to a previous thread that would be great (did a search but got zero returns). Thx



My thoughts - the 5.45 is a very fun blaster where you can buy a rifle, mags, and ammo fairly cheap. You can blast a whole case, probably not have any problems, throw it in the corner without cleaning, and not feel guilty. The next time you buy ammo - be it a week or a year later - it will work with no problems.

The 5.56 is a fun gun that you can really put a lot of money into. You can get the bottom basement guns for $600 or so and then expand the rifle's capabilities until you've got several thousand dollars tied up in it. The platform is very versatile and can do almost anything you ask of it (within reason).

Other thoughts - if you want a 5.56 buy an AR - don't try to play with 5.56 AKs until someone standardizes them! And the same goes for the 5.45 - stick with the AK platform.

In a straight comparison of the two - I like both - honestly! Both are fun, the 5.45 is extremely light recoiling and just a lot of fun to shoot. I like the AR because I can put all the crap on it and look like a real poser...

Spooky
Link Posted: 12/28/2005 12:46:10 PM EDT
[Last Edit: 12/28/2005 12:46:34 PM EDT by Forest]

Originally Posted By Creeper:
Mass x Velocity = energy transferred.


Not only is that incorrect, the idea of 'energy transfer' is a concept that was dreamed up by people too lazy to do any research on the hows/whys of terminal ballistics.


My point is simple, if the russians designed a round that is independent of velocity and can produce similiar wounding capability to greater distances because it is independent of velocity then perhaps it is something worth taking a look at to incorporate into 5.56 rounds which overall lose capability under certain velocity.


Your point is "We should build a round that produces a smaller wound channel because somebody else uses it". Let's look at the facts for a moment. The 5.45 produces a smaller wound channel than M193, Mk262, and 75gr OTM.

Fact 1: Most rifle combat takes place at 100y or less.
Fact 2: At typical combat distancess all the previous mentioned rounds will create significanly larger permanent wound channels thanks to their ability to fragment. Range will vary depending on barrel used and the particular round.
Fact 3: Beyond the rounds fragmentation range the previously mentioned rounds will still yaw producing wound channels similar to the 5.45 only with a single 'lobe'. The fact the 70gr loads are also longer (and wider) cutting a larger swath.


Well you tell me, since clearly 5.56 effective killing ranges are limited on velocity when the Russians designed similiar weighted rounds that are independent of velocity and have longer killing distance ranges.

You gotta tell me where do you get ideas like this? We got guys with SPRs and M4s killing Taliban at 500-600M in Afghanistan with 5.56 what could possibly make you think it's not deadly at extended ranges.


Basically our designed rounds are nothing much more than .22's

Still 'stuck' I see.


with a lead plug in the rear that upon impact the lead slams foward, causing the jacket to expand, and the round to tumble. Simple, effective, and independent of magical velocity or weight thresholds.

Except you got it all wrong.
1) the plug is soft steel not lead.
2) The jacket doesn't expand
3) ALL bullets will yaw (they don't tumble), especially the ones I've already mentioned.


Thinking outside the box even for a moment is sometimes OK.

Please let us know when you start 'thinking'. Cause till now you've been spewing a bunch of garbage.
Link Posted: 12/28/2005 4:28:07 PM EDT
Get a 5.45 AK. They are very cool.

You can get one for less than a quality AR. It's a neat round, with the russian style muzzle brake there is nearly zero recoil. It's a hoot!

Dig the cold war vibe it emits, don't compare the two. Shoot it and enjoy.

Link Posted: 12/28/2005 5:12:40 PM EDT
eodinert
]"Dig the cold war vibe it emits, don't compare the two. Shoot it and enjoy"

Thanks for this statement. I totally agree!

You can argue until the cows come home. Both of these rounds are effective against personnel.
The lethality of both rounds is beyond question, both having proven themselves over decades on many battlefields that produced a tremendous amount of KIAs and wounded.
Just ask the Mujhadeen or the North Vietnamese Army.

Arguing which is incrementaly better is beyond being picky, it's inane.

Time to go.
Link Posted: 12/28/2005 5:34:06 PM EDT
Calling people stupid is a little over the line. Can you not just disagree?
Link Posted: 12/28/2005 5:42:57 PM EDT

Originally Posted By Clint50:
Calling people stupid is a little over the line. Can you not just disagree?



Forest has spent 5 years trying to explain these things, I understand his frustration.
Link Posted: 12/28/2005 5:47:55 PM EDT

Originally Posted By Combat_Jack:
Originally Posted By Clint50:
Calling people stupid is a little over the line. Can you not just disagree?



+1
Link Posted: 12/28/2005 5:59:13 PM EDT
Energy Transferred? Energy transfer does not mean jack. If the bullet strikes a ceramic plate vest carrier whatnot it transfers all of its energy to the wearer. It did not do jack. If an arrow strikes a, unarmored body it flies straight through not losing much of its whole 50 pounds of energy or so.

Transfer does not mean near as much as damage done. Russian ammo, like ALL spitzer ammo yaws. The only advantage of the Russian ammo is that it will effectively yaw with a nice short neck more reliably than our ammo will fragment, and yawing is not dependent on speed as much as fragmentation. Our ammo yaws, and if it is past a certain velocity threshold it fragments. I do not know if our ammo begins to yaw as quickly as russian ammo.

I am still learning all this stuff, but I am coming to the conclusion that it is kind of a moot point. If you are going to use a gun for Home defense, the obvious choice is .223/5.56 due to the plethora of HP/SP/BT ammo available for it. You are not limited to FMJ that may or may not frag/yaw/perform magical death dances in the bodies of targets.

When it comes to the military value of each cartridge, our respective countries chose the caliber which worked best for their own platforms and style of fighting. I believe that we have made some mistakes in using ammunition meant for Ruskies with body armor on Skinnies in t-shirts, but that is a different issue.

Listen to Forest, and goto the website in his sig line.
Link Posted: 12/28/2005 6:20:29 PM EDT
[Last Edit: 12/28/2005 6:26:08 PM EDT by HeavyMetal]
Link Posted: 12/28/2005 6:33:16 PM EDT
Link Posted: 12/28/2005 7:05:18 PM EDT
[Last Edit: 12/28/2005 7:12:37 PM EDT by omar]

My thoughts - the 5.45 is a very fun blaster where you can buy a rifle, mags, and ammo fairly cheap. You can blast a whole case, probably not have any problems, throw it in the corner without cleaning, and not feel guilty. The next time you buy ammo - be it a week or a year later - it will work with no problems.


Yep. It's a low/no maintenance rifle. I only run a boresnake through my 74's and that's mainly to verify I have a clear bore prior to firing.

I have thought about switching to 5.56 in my AKs to simplify my ammo holdings.

Here's the 16" crew:

Link Posted: 12/28/2005 7:30:40 PM EDT
I beleive Peter J Kokalis from soldier of fortune magazine was the first to debunk the myth of 5.45 being better and having better terminal balistics.He was the first through his contacts for a westerner to see the AK74 as well as its ammo.The article he wrote appeared in soldier of fortune in 1983.You can see a copy of the article in Weapon tests and evaluations by Peter J Kokalis..ISBN#1581601220.The first large quanities of this ammo was obtained by SOF publiusher Robert K Brown and turned over to the Army and NRA for testing...20 years ago.5.45 old news with nothing spectacular about the ammo.
Link Posted: 12/28/2005 7:41:33 PM EDT

Originally Posted By Combat_Jack:

Originally Posted By Clint50:
Calling people stupid is a little over the line. Can you not just disagree?



Forest has spent 5 years trying to explain these things, I understand his frustration.



Sorry,Jack. I haven't been on here very long.
Link Posted: 12/28/2005 8:21:25 PM EDT
[Last Edit: 12/28/2005 8:22:33 PM EDT by Combat_Jack]

Originally Posted By Clint50:

Originally Posted By Combat_Jack:

Originally Posted By Clint50:
Calling people stupid is a little over the line. Can you not just disagree?



Forest has spent 5 years trying to explain these things, I understand his frustration.



Sorry,Jack. I haven't been on here very long.



Not trying to criticize anyone, but there is a LOT of information available. When I started out I looked around a lot. My high post count comes from later.

It just get's old dealing with the same questions when we have already made available all the information that we have- and then pople won't listen.

So I think you have the right attitude. Just read until your eyes hurt before you ask- that way you'll get the questions right.
Link Posted: 12/29/2005 8:14:19 AM EDT

Originally Posted By Clint50:
Calling people stupid is a little over the line. Can you not just disagree?



I think Jack covered this (Thanks Jack!), and it's the reason why people like Brouhaha don't come around much anymore.

The data is available, and still people won't learn. Then things like the Ammo Oracle, then Brouhaha's and Tatjana's website went up (they are the ones hosting all of those great papers from Dr Fackler) to make it easier for people to find hard data. And still we have the "gunshow commandos" come by and post their unsupportable drivel. It makes it even worse when the person doing it has been posting here since 2001 and should not only have seen this data posted 100s of times, but the idea he was trying to push has been pushed here (both on the AR & AK sides of the house) numerous times and shot down numerous times....

Link Posted: 12/29/2005 9:54:25 AM EDT
[Last Edit: 12/29/2005 9:55:43 AM EDT by DevL]
Since noone mentioned it the 75 grain OTM already has a air pocket at the tip and yaws as fast as 5.45 past the fragmenting range due to bulet shape and ceneter of gravity is more towrd the rear because of that air pocket that is created because of the way OTM bullets are made. Its more accurate than the Russian civilian or military versions of 5.45 so its better all arounds at all ranges. Just thought it was funny someone was trying to say there should be an air pocket at the tip when there was already one.

I think people should at least have a working knowledge of the projectiles before they strt stating what "should" be done to a projectile to improve it.
Link Posted: 12/29/2005 10:22:10 AM EDT
so only fragmentation and yaw matters in delivering damage- energy transfer means nothing? only hole size? why doesn't 9mm deliver more damage than 308 then, if both are fmj?
Link Posted: 12/29/2005 10:56:13 AM EDT
[Last Edit: 12/29/2005 11:01:53 AM EDT by DevL]

Originally Posted By mrmoshzilla:
so only fragmentation and yaw matters in delivering damage- energy transfer means nothing? only hole size? why doesn't 9mm deliver more damage than 308 then, if both are fmj?



Yes that is true but you should say only tissue damage matters. 308 in any form other than FMJ fragments or expands to a greater degree than 9mm. It s higher velocity also has a MUCH greater temporary cavity which can cause tissue damage in inelastic structures liek your liver. Pistol rouds have a relativly weak and small temporary cavity in comparison and it should not be reiled upon to cause significant tissue damage. Ther are times when a non fragmenting 308 FMJ will have less tissue destruction than a 9mm... a shot through your hand where no bone is hit for example where the temporary cavity of the 308 cant do any real damage.

THe key thing to remember is ENERGY TRANSFER MEANS NOTHING. Anyone trying to use that term can be looked upon as a fraud. A bow firing a broadhead arrow imparts massive tissue damage to vital structures... it transfers very little energy. An energy dump is waht you do int the morning after a strong cup of coffee.
Link Posted: 12/29/2005 11:00:51 AM EDT

Originally Posted By mrmoshzilla:
so only fragmentation and yaw matters in delivering damage- energy transfer means nothing? only hole size? why doesn't 9mm deliver more damage than 308 then, if both are fmj?



Because it has better penetration and it can yaw, but M80 ball still is not better then 5.56mm inside of it's fragmentation threshold.
Link Posted: 12/29/2005 11:12:41 AM EDT

Originally Posted By DevL:

Originally Posted By mrmoshzilla:
so only fragmentation and yaw matters in delivering damage- energy transfer means nothing? only hole size? why doesn't 9mm deliver more damage than 308 then, if both are fmj?



Yes that is true but you should say only tissue damage matters. 308 in any form other than FMJ fragments or expands to a greater degree than 9mm. It s higher velocity also has a MUCH greater temporary cavity which can cause tissue damage in inelastic structures liek your liver. Pistol rouds have a relativly weak and small temporary cavity in comparison and it should not be reiled upon to cause significant tissue damage. Ther are times when a non fragmenting 308 FMJ will have less tissue destruction than a 9mm... a shot through your hand where no bone is hit for example where the temporary cavity of the 308 cant do any real damage.

THe key thing to remember is ENERGY TRANSFER MEANS NOTHING. Anyone trying to use that term can be looked upon as a fraud. A bow firing a broadhead arrow imparts massive tissue damage to vital structures... it transfers very little energy. An energy dump is waht you do int the morning after a strong cup of coffee.



this is really counter-intuitive. I thought fackler said that temporary cavity is meaningless..? but this would make sense in why the commies came up with 7.62x39, it would be equal to 7.62x54 in fmj that held together where you're just trying to poke the largest hole possible.
Link Posted: 12/29/2005 11:17:13 AM EDT
[Last Edit: 12/29/2005 11:34:14 AM EDT by Forest]
Originally Posted By mrmoshzilla:
I thought fackler said that temporary cavity is meaningless..?

No what he said is (and I'm paraphrasing here) "Temporary cavity is meaningless UNLESS you hit an in-elastic organ (liver or brain) or an organ filled with liquid (like the bladder)".
Link Posted: 12/29/2005 11:27:56 AM EDT
In elastic structures temp cavities cause trauma similar to severe contusions. In inelastic structers they tear them apart.
Link Posted: 12/29/2005 11:35:18 AM EDT
And if you want lots of temporary cavity and lots of fragmentation destruction then you should get some TAP .308 155gr A-MAX.
Link Posted: 12/29/2005 11:38:32 AM EDT

Originally Posted By 556Cliff:
And if you want lots of temporary cavity and lots of fragmentation destruction then you should get some TAP .308 155gr A-MAX.



To be sure, unfortunelty the last time I tried feeding .308 into my ARs it wouldn't fit into my magazines..
Link Posted: 12/29/2005 11:53:26 AM EDT
[Last Edit: 12/29/2005 11:56:42 AM EDT by 556Cliff]

Originally Posted By Forest:

Originally Posted By 556Cliff:
And if you want lots of temporary cavity and lots of fragmentation destruction then you should get some TAP .308 155gr A-MAX.



To be sure, unfortunelty the last time I tried feeding .308 into my ARs it wouldn't fit into my magazines..



Son are you "stuck on stupid"? Get an AR10.
Link Posted: 12/29/2005 11:56:33 AM EDT

Originally Posted By 556Cliff:

Son are you "stuck on stupid"? Get an AR10



LOL - I did better! I got a 6.8! - most of the .308 ballistics with the size, weight, and reliability of the AR-15 platform.
Link Posted: 12/29/2005 12:03:56 PM EDT

Originally Posted By Forest:

Originally Posted By 556Cliff:

Son are you "stuck on stupid"? Get an AR10



LOL - I did better! I got a 6.8! - most of the .308 ballistics with the size, weight, and reliability of the AR-15 platform.



Best of both worlds. Some day I'll have one of those, but it will be with a gas piston upper.
Link Posted: 12/29/2005 12:44:52 PM EDT
Son are you "stuck on stupid"? Get an AR10.

My favorite!
Link Posted: 12/29/2005 3:37:57 PM EDT

Originally Posted By DevL:
I think people should at least have a working knowledge of the projectiles before they strt stating what "should" be done to a projectile to improve it.


While that statement is incredibly profound and applicable, I am afraid that you are just asking way too much.
The info has been offered- hand delivered even- and he doesn't see it.
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