Looking for my first rifle!

[Brasky]

AR:
https://youtu.be/YAneTFiz5WU
AK:
https://youtu.be/DX73uXs3xGU
Vz58:
https://youtu.be/f3kComQz40o

The first two basically match up with the results from my informal AR and AK mud testing I did for my own amusement.

I can't imagine any situation where I would be forced to wade a swamp with my gun under the mud. I can see a situation for a sand tornado test where folks live in a desert climate. Realistically in my area more realistic tests would be dunked in snow, soaked in rain, and fired without cleaning

[mdi_weapon]

AR:
https://youtu.be/YAneTFiz5WU
AK:
https://youtu.be/DX73uXs3xGU
Vz58:
https://youtu.be/f3kComQz40o

The first two basically match up with the results from my informal AR and AK mud testing I did for my own amusement.

I can't imagine any situation where I would be forced to wade a swamp with my gun under the mud. I can see a situation for a sand tornado test where folks live in a desert climate. Realistically in my area more realistic tests would be dunked in snow, soaked in rain, and fired without cleaning

That has always been my general opinion of many of the radical torture tests you see for firearms. The original ones for the Glock always cracked me up...it can be frozen in a block of ice and then hammered out and it will work....it can be dropped out of a helicopter from 200 feet, bounce off the concrete and work! Umm. So what? If I am with the gun, I am dead in either case.

That being said, it is bleep shocking to see the AR15 actually work after that. It is contrary to its Internet reputation.

[MeatAxe]

AR:
https://youtu.be/YAneTFiz5WU
AK:
https://youtu.be/DX73uXs3xGU
Vz58:
https://youtu.be/f3kComQz40o

The first two basically match up with the results from my informal AR and AK mud testing I did for my own amusement.

I can't imagine any situation where I would be forced to wade a swamp with my gun under the mud. I can see a situation for a sand tornado test where folks live in a desert climate. Realistically in my area more realistic tests would be dunked in snow, soaked in rain, and fired without cleaning

That has always been my general opinion of many of the radical torture tests you see for firearms. The original ones for the Glock always cracked me up...it can be frozen in a block of ice and then hammered out and it will work....it can be dropped out of a helicopter from 200 feet, bounce off the concrete and work! Umm. So what? If I am with the gun, I am dead in either case.

That being said, it is bleep shocking to see the AR15 actually work after that. It is contrary to its Internet reputation.

Well, whatever you do, NEVER, EVER let your DI AR15 get wet and try to use it (I mean water only covers 3/4 of the world's surface, so what could happen?). It will blow up, literally:

https://www.youtube.com/watch?v=AGwkHktkTxU


AK? No problem:

https://www.youtube.com/watch?v=mzwdCCNwn4M


Of course, even the most inexperienced shooter could probably guess that it's not standard procedure to pour dirt / sand / mud directly into the internals of your firearm before you try to shoot it.

The main problem with the AR15 DI system (aside from water) it that it !@##s where it eats: powder fouling and extreme heat is blown directly into the action every time it is fired, requiring constant maintenance to keep it running, even in the best of conditions.

A civilian in a SHTF scenario may not have time to constantly clean his weapon and doesn't have a 10,000 mile supply chain, fortified bases to go to to clean his weapon or the ability to call in air strikes when he gets into trouble, so a good AK or Vz are a better choice as a semi-auto self-defense / survival gun, especially with the hard-hitting 7.62x39 round as opposed to .223 / 5.56 which has trouble penetrating common urban barriers,

[RSR]

I think we're getting entirely off topic now...  This is first time rifle buyer who by now is surely entirely confused...  Apologies OP for feeding this fire.

The mud test has already been covered here: http://www.czfirearms.us/index.php?topic=76441.0
Bottom line, that's a level of neglect and abuse rarely seen...

MeatAxe, all .223 weapons have an issue w/ water remaining in barrels unless seal is broken due to surface tension, etc...  30 caliber weapons don't have that issue; though the DI buffer tube even on 308s can hold water if seal isn't broken by pulling charging handle, etc...  Secondly, DI ARs because they cycle gas that compresses, when water is in the system it causes much more force to be applied to the bolt carrier since water compresses less than gas...
Lastly, worth noting that standard AR receiver extensions don't have enough drainage holes (well just one on rear of buffer tube) to allow proper function of buffer either when rapidly firing from submerged, so with a tremendous amount of pressure to front and rear of bcg, the bcg goes sideways which kills the upper like  in the vidoe. 
On my AR builds, I use the POF buffer extension (last couple I ordered have an ugly white POF logo on the side by receiver however...) that is $10 or so more expensive than standard milspec extensions (POF is milspec aluminum and anodizing while many AR buffer tubes are not...  Main reasons are the tube 1) locks with the buffer retainer pin to prevent rotation, 2) eliminates much of the possibility for carrier tilt since buffer tube fully supports the carrier rear, 3) the extra drainage holes aren't a bad thing either, and 4) quality of manufacture is top notch which means better stock fit too...

Bottom line, DI guns are dangerous to fire when submerged, but just like the InRange mud test, that's not the end all be all of a firearm.

[MeatAxe]

I think we're getting entirely off topic now...  This is first time rifle buyer who by now is surely entirely confused...  Apologies OP for feeding this fire.

The mud test has already been covered here: http://www.czfirearms.us/index.php?topic=76441.0
Bottom line, that's a level of neglect and abuse rarely seen...

MeatAxe, all .223 weapons have an issue w/ water remaining in barrels unless seal is broken due to surface tension, etc...  30 caliber weapons don't have that issue; though the DI buffer tube even on 308s can hold water if seal isn't broken by pulling charging handle, etc...  Secondly, DI ARs because they cycle gas that compresses, when water is in the system it causes much more force to be applied to the bolt carrier since water compresses less than gas...
Lastly, worth noting that standard AR receiver extensions don't have enough drainage holes (well just one on rear of buffer tube) to allow proper function of buffer either when rapidly firing from submerged, so with a tremendous amount of pressure to front and rear of bcg, the bcg goes sideways which kills the upper like  in the vidoe. 
On my AR builds, I use the POF buffer extension (last couple I ordered have an ugly white POF logo on the side by receiver however...) that is $10 or so more expensive than standard milspec extensions (POF is milspec aluminum and anodizing while many AR buffer tubes are not...  Main reasons are the tube 1) locks with the buffer retainer pin to prevent rotation, 2) eliminates much of the possibility for carrier tilt since buffer tube fully supports the carrier rear, 3) the extra drainage holes aren't a bad thing either, and 4) quality of manufacture is top notch which means better stock fit too...

Bottom line, DI guns are dangerous to fire when submerged, but just like the InRange mud test, that's not the end all be all of a firearm.

Well, the HK .223 didn't blow up in / underwater, so it's not the caliber. The issue is that the AR15 direct impingement is fraught with a lot of problems (excessive heat, powder / carbon fouling, demands constant maintenance, etc. etc. to name a few -- and blows up if you happen to drop in the water and then have to fire it to save your life -- e.g. in the rice paddies of Viet Nam).

If you want a drop dead reliable semi-auto rifle, piston guns are better than DI, preferably in a serious caliber. The AR15 and 5.56 caliber were picked by the bean counters at DOD (Whiz Kid Robt. McNamara  of Viet Nam War strategy fame) because Gen. Curtis LaMay was impressed with the space-aged look of the AR15 and at how it blew up watermelons when demonstrated at a picnic. LeMay may have been a genius at strategic aerial bombing, but he had no business having any influence in picking an infantry rifle.

And GIs have been stuck with that poodle-shooter turkey going on 60 years. Arguably the worst combat rifle & cartridge (for its time) in US military history has been deployed for the longest time. Incredible.

[MeatAxe]

As a replacement to the M1 carbine for non-infantry troops, the 5.56 m4/16 is a solid improvement -- in most instances a more effective round especially if just exclusively fmj, and the AR is pretty well sealed from elements and dirt with mag in, muzzle condom on, and dust cover closed so with limited use and infrequent cleanings, whether stored on rack or carried for security/perimeter patrols, it should work when needed.  That's probably a lot about why the US Air Force was the first to adopt... 

As a general purpose military front line infantry carbine/rifle I find 5.56 lacking...  Logistically, however I don't see the need for a full-sized .308 rifle in most types of combat...  Double weight of .308 rounds vs 5.56 just doesn't make sense when one looks at how bullets are expended in combat zones.
Militarily, most small arms fire is intended for suppression and fixing the enemy, so odds of a given bullet actually hitting an enemy soldier is low.
This marine document on the depuy fighting positions, has a stat of 12 kills per 100 rounds fired for defenders shooting from positions of cover, pretty much a best-case combat scenario: http://www.2ndbn5thmar.com/fight/whythedepuyfightinghole.pdf

In Afghanistan, the GAO estimates US troops fire 250,000 rounds for every enemy insurgent killed -- that's about $75 grand in ammo costs (by commercial bulk retail pricing) BEFORE you account for the abhorrent costs of shipping anything to and within that country: http://www.belfasttelegraph.co.uk/news/world-news/us-forced-to-import-bullets-from-israel-as-troops-use-250000-for-every-rebel-killed-28580666.html

Back to the original point, while yes the .308 is more powerful, within 250-300 yards the 7.62x39 can do pretty much everything .308 can do and often better, with perhaps a small exception of .308's greater penetration against steels solely due to higher velocity.  .308's energy inside of 250-300 yards generally is too much power and results in much longer penetration necks in gelatin with similar issues to the m855 ammo with through and through pencil holes with little energy deposited in the enemy -- yes .308 is a 30 caliber hole in this instance vs a 22 caliber pencil holes for 5.56, but insofar as pencil holes'/permanent cavity there shouldn't be much difference between a 9mm round and a .308 going through and through, the temporary stretch cavity is where differences come in. 
While in the weeds, the main point here is that if anticipating a substantial amount of engagements beyond 300m, .308 shines.  If anticipating most to all engagements within 300m, then 7.62x39 shines.  Most folks who deem the .308 caliber/rifles to be paramount for combat have an argument that essentially distills down to that they'll pick off their foes at 500 yards (or other extreme range) -- which doesn't really account for the fact that no human will willing be a sitting duck so will seek cover/concealment, the likely limited marksmanship of most of these types including the challenges related to ranging and limited exposure of enemy once they know they are in the crosshairs that won't allow multiple shots at same target at same place (it won't be a static range), etc...

Back to the military, m4s are primarily used for combat at distances where supporting/combined arms cannot be used -- whether unit rifle grenades and mortars, supporting artillery, or air, troops typically can and are taught to engage enemy at range with these assets and small arms merely use to suppress and pin down the enemy to be killed by methods other than small arms... 
And even in the small arms realm, individually portable squad automatic weapons are considered the primary tool for enemy engagement...  But with most US infantry now being vehicle-borne troops, .30 and .50 cal vehicle mounted machine guns and grenade launchers typically are used in place of or preferable to M4s for engagements at all distances...
When you're talking about danger-close grenade range combat, the M4 and 5.56 round does perform sufficiently in most cases...

Also worth noting that modern small caliber high velocity rounds with shorter effective ranges have been outgunned by old bolt action rifles in service calibers in Afghanistan, primarily a matter of range, but worth noting...
http://cominganarchy.com/2010/05/21/it-took-us-nine-years-to-figure-this-out/
http://archive.boston.com/news/world/asia/articles/2010/05/21/us_rifles_not_suited_to_warfare_in_afghan_hills/

Ultimate point here is to have at least a high-level understanding as to all the ways and reasons compromises are being considered.  For the military it's seldom about the "best" but rather about logistics, procurement, and pacifying the bureaucratic officer corps and all the varying stakeholders that have different priorities than optimal terminal performance, weapon reliability, etc...

All considered is why that while 7.62x39 weighs ~45% more than 5.56, it's potential to be more effective, require only one shot to put an enemy out of action vs a couple shots with 5.56, better in short barrels, cases chamber/extract more reliably, etc, just aren't a primary concern...
*stealing ammo weights from here: http://forum.saiga-12.com/index.php?/topic/65272-how-does-weight-compare-between-steel-case-762x39-and-brass-223/

200 rounds of steel-cased 7.62x39 122 grain weighs 7.22 lbs. (1000 rounds = 36.15 lbs)
200 rounds of brass-cased .223 55 grain weighs 5.02 lbs. (1000 rounds = 25.13 lbs)
200 rounds of 2 3/4 12 ga 00 bk weighs 19.18 lbs. (1000 rounds = 95.90 lbs)
200 rounds of 7.62x51 146 grain weighs 10.86 lbs. (1000 rounds = 54.30 lbs)

The figures for the 7.62x51 was supplied to me by someone else so I can't guarantee it's accuracy but it seems right to me. The other calibers I personally weighed so they are accurate. The difference between the 7.62x39 and .223 is about 2 lbs. The figures kind of screw up the idea of carrying around thousands of rounds on foot.

From a civilian, for self defense within 100 yards (unless your part of the country has frequent gunfights, should cover all legally justifiable self-defense scenarios -- at least before the zombies come), 5.56 is an adequate performer especially with premium non-fmj ammo.  It also generally produces less recoil, is lighter, is a more compact round, and in the VZ58 uses AR mags, which are almost as awesome as glock mags.   
But again, 7.62x39 is better for hunting, barrier penetration, and as a combat small arm at carbine (~300 yard or less range), especially if you don't have mgs, supporting arms, etc, like the military does...

Define your needs and make a choice -- any gun is better than no gun.  There's no wrong answer, just differing opinions -- but those whose opinions' differ may decide your opinion/decision is wrong...  haha

US Ordnance was actually on the right track in the early 1920s (almost a hundred years ago now) when they came close to adopting the .276 Pedersen round, a flat-shooting, intermediate powered cartridge, which was the first chambering of the M1 Garand. Funny thing, the .276 Pedersen had almost identical ballistics to the 6.5 Grendel and the 6.8 SPC, which are recognized as the long-overdue replacement for the anemic 5.56. Of course, the 6.5 Grendel is basically a necked-down 7.62x39 round but tapered to fit an AR platform (regrettably).

Unfortunately, the bean counters won and the US stuck with the .30'06 (along with the anemic .30 Carbine for support troops) through the Korean War.

Then when NATO came about, the US forced everyone to adopt the 7.62x51 (near identical to the .30'06 ballistically) even though the .280 British cartridge was proposed (ballistically near identical to the .276 Pedersen, the 6.5 Grendel and the 6.8 SPC -- you get the picture).

It seems the US Ordnance never misses an opportunity to miss an opportunity as far as picking out an infantry rifle / cartridge.

[MeatAxe]

Hi everyone,

I am pretty obsessed with Commie guns, and Czech guns in particular. Always was fascinated with them for some reason. So I am looking to get my first rifle and I am leaning toward a VZ-58, even though I know almost nothing about them. That or something like the Arsenal SGL-31 AK-74.

Visually I really like the look of this VZ58:



My only use will be range fun.

Would the VZ be a good choice for a first rifle? It would be kind of cool to have such a unique gun. I've never seen anyone with one at the range. They almost all have AR's and a few AK's.... but no VZ58's in sight.

I think you would be well-served with either a good drop dead reliable imported AK or a CSA Vz58 chambered in the hard-hitting and relatively inexpensive 7.62x39. Arsenals are great, especially the milled SAM7 rifles. I would steer clear of 5.45 because 99% of it comes from Russia, which could be subject to an ammo ban (as Saigas are now).

The AK has the advantage over the Vz in parts, accessories and magazine availability (50,000,000 vs. @ 1 million produced world wide), but a Vz is a nice shooting weapon.

Also, for range fun, you'll spend more time (and less money) shooting an AK or a Vz and less time having to constantly maintain your rifle as you would with an AR. Not fun. I'd rather shoot than clean any day. Plus, 5.56 is more expensive than 7.62x39.

Then again, if you have to use it for a self-defense SHTF rifle (notwithstanding if you feel compelled to drop dirt/sand/mud inside the action), you can be sure that a good AK will go bang when you pull the trigger and need to knock something down (ARs, not so much without a lot of attention to maintenance).

[mdi_weapon]

AR:
https://youtu.be/YAneTFiz5WU
AK:
https://youtu.be/DX73uXs3xGU
Vz58:
https://youtu.be/f3kComQz40o

The first two basically match up with the results from my informal AR and AK mud testing I did for my own amusement.

I can't imagine any situation where I would be forced to wade a swamp with my gun under the mud. I can see a situation for a sand tornado test where folks live in a desert climate. Realistically in my area more realistic tests would be dunked in snow, soaked in rain, and fired without cleaning

That has always been my general opinion of many of the radical torture tests you see for firearms. The original ones for the Glock always cracked me up...it can be frozen in a block of ice and then hammered out and it will work....it can be dropped out of a helicopter from 200 feet, bounce off the concrete and work! Umm. So what? If I am with the gun, I am dead in either case.

That being said, it is bleep shocking to see the AR15 actually work after that. It is contrary to its Internet reputation.

Well, whatever you do, NEVER, EVER let your DI AR15 get wet and try to use it (I mean water only covers 3/4 of the world's surface, so what could happen?). It will blow up, literally:

https://www.youtube.com/watch?v=AGwkHktkTxU


AK? No problem:

https://www.youtube.com/watch?v=mzwdCCNwn4M


Of course, even the most inexperienced shooter could probably guess that it's not standard procedure to pour dirt / sand / mud directly into the internals of your firearm before you try to shoot it.

The main problem with the AR15 DI system (aside from water) it that it !@##s where it eats: powder fouling and extreme heat is blown directly into the action every time it is fired, requiring constant maintenance to keep it running, even in the best of conditions.

A civilian in a SHTF scenario may not have time to constantly clean his weapon and doesn't have a 10,000 mile supply chain, fortified bases to go to to clean his weapon or the ability to call in air strikes when he gets into trouble, so a good AK or Vz are a better choice as a semi-auto self-defense / survival gun, especially with the hard-hitting 7.62x39 round as opposed to .223 / 5.56 which has trouble penetrating common urban barriers,

Lol. Have you not paid attention to the design on the SR762? Or the SR556?

AR's blow up or will lot run in water? That is complete nonsense. Mine has been soaking wet on a number of occasions and it shoots without any problems. Do you think the SEALs use Mk12s and Mk18s because they don't work in wet environments? No. I am fairly sure they dunk them in the ocean just like all of their other guns and those are both AR designs.

Speaking of the Mk18 mod 2....It is also used by the U.S. Coast Guard's Tactical Law Enforcement Teams, Maritime Safety and Security Teams, and Maritime Security Response Team and the United States Navy's Explosive Ordnance Disposal (EOD) Operators. It is also used by Marine Force Recon's CQB operators, and is in most cases the standard weapons of choice for said operators. Do you think those guys do not get them wet?? Surely the US Navy and US Coast Guard are never around water.

ARs don't penetrate urban barriers? Have you shot an AR loaded with M855 SS109 in this lifetime??

ARs won't run dirty? More nonsense. See the mud test above. Without crazy conditions like those I have gone months without cleaning my AR and it runs without any hangups whatsoever. If finished in Black T or RF85, they even run without lube (as in completely dry).

[gwvt]

Holy cow, you guys! The OP asked a simple question. My simple answer is 'yes!' In my experience, new shooters do well with the VZ-58/2008. I also second RSR's suggestion to get a 10/22, regardless. They're cheap, reliable, easy to customize and they shoot a round that costs 1/4-1/2 the price of steel 7.62x39. .22lr is a great caliber for new shooters to learn on and experienced shooters to practice with or just plain have fun with.

[Franz Maurer]

Lol. Have you not paid attention to the design on the SR762? Or the SR556?

AR's blow up or will lot run in water? That is complete nonsense.Mine has been soaking wet on a number of occasions and it shoots without any problems. Do you think the SEALs use Mk12s and Mk18s because they don't work in wet environments? No. I am fairly sure they dunk them in the ocean just like all of their other guns and those are both AR designs.

Speaking of the Mk18 mod 2....It is also used by the U.S. Coast Guard's Tactical Law Enforcement Teams, Maritime Safety and Security Teams, and Maritime Security Response Team and the United States Navy's Explosive Ordnance Disposal (EOD) Operators. It is also used by Marine Force Recon's CQB operators, and is in most cases the standard weapons of choice for said operators. Do you think those guys do not get them wet?? Surely the US Navy and US Coast Guard are never around water.

ARs don't penetrate urban barriers? Have you shot an AR loaded with M855 SS109 in this lifetime??

ARs won't run dirty? More nonsense. See the mud test above. Without crazy conditions like those I have gone months without cleaning my AR and it runs without any hangups whatsoever. If finished in Black T or RF85, they even run without lube (as in completely dry.)

[mdi_weapon]

Not sure that scrub brush attachment is milspec...

I agree with the 10/22 suggestion. If you want a really inexpensive option, Savage also has a semi-auto .22LR that is truly dirt cheap - it can often be found for around $110 but it doesn't have the aftermarket support of the 10/22. The Savage bolt action Mark II FV-SR .22 is another great starter rifle - especially if you want to jump on a precision bolt action rifle in the future. However, the bolt action option opens the door for another type of firearms addiction. You will end up taking up at least one side of a gun safe with them sooner or later.

[gwvt]

At least we know he's not 'running it dirty'!

[RSR]

Well, the HK .223 didn't blow up in / underwater, so it's not the caliber. The issue is that the AR15 direct impingement is fraught with a lot of problems (excessive heat, powder / carbon fouling, demands constant maintenance, etc. etc. to name a few -- and blows up if you happen to drop in the water and then have to fire it to save your life -- e.g. in the rice paddies of Viet Nam).

If you want a drop dead reliable semi-auto rifle, piston guns are better than DI, preferably in a serious caliber. The AR15 and 5.56 caliber were picked by the bean counters at DOD (Whiz Kid Robt. McNamara  of Viet Nam War strategy fame) because Gen. Curtis LaMay was impressed with the space-aged look of the AR15 and at how it blew up watermelons when demonstrated at a picnic. LeMay may have been a genius at strategic aerial bombing, but he had no business having any influence in picking an infantry rifle.

And GIs have been stuck with that poodle-shooter turkey going on 60 years. Arguably the worst combat rifle & cartridge (for its time) in US military history has been deployed for the longest time. Incredible.

HKs have a very heavy barrel profile which is what was required to achieve similar accuracy to DI guns due to the piston system's effect on barrel harmonics -- that 10" barrel HK weighs about the same a 16" A2 profile DI gun. 
Again, the reasons for the fracturing of the upper receiver were noted -- drainage holes in buffer tube and how the DI system works (liquids don't be have like gasses, so when liquid in the gas system, there's issues). 
The point about .223 rifles is that the barrel can burst when any obstruction, including water is in the bore.  With round loaded in chamber and surface tension of water in .22 cal barrel, the water effectively holds itself in barrel unless seal is broken on chamber end -- much like holding finger over one end of a straw.

You're also incorrect on LeMay forcing it onto infantry. He wanted it for Air Force base security -- to replace the M1/M2 carbine whose ammo was relatively ineffective in FMJ/ball verison vs 5.56 AND had serious reliability issues in full auto mode (including magazines), leading most to be used in semi auto only. 
Congress and the Pentagon shut down the Air Force buy, and ultimately Pentagon and the President forced the weapon onto the resistant Army and Marines.  You can read more here: http://www.gundigest.com/article/the-ar-16m16-the-rifle-that-was-never-supposed-to-be

The last is entirely your opinion and you're welcome to it, but let's at least keep the facts straight. 

[RSR]

US Ordnance was actually on the right track in the early 1920s (almost a hundred years ago now) when they came close to adopting the .276 Pedersen round, a flat-shooting, intermediate powered cartridge, which was the first chambering of the M1 Garand. Funny thing, the .276 Pedersen had almost identical ballistics to the 6.5 Grendel and the 6.8 SPC, which are recognized as the long-overdue replacement for the anemic 5.56. Of course, the 6.5 Grendel is basically a necked-down 7.62x39 round but tapered to fit an AR platform (regrettably).

Unfortunately, the bean counters won and the US stuck with the .30'06 (along with the anemic .30 Carbine for support troops) through the Korean War.

Then when NATO came about, the US forced everyone to adopt the 7.62x51 (near identical to the .30'06 ballistically) even though the .280 British cartridge was proposed (ballistically near identical to the .276 Pedersen, the 6.5 Grendel and the 6.8 SPC -- you get the picture).

It seems the US Ordnance never misses an opportunity to miss an opportunity as far as picking out an infantry rifle / cartridge.

I agree that .276 P would have been a superior choice to .30-06 for the M1 Garand.  However, .276 P is effectively a flatter shooting, higher velocity .308 -- and it actually has a longer overall cartridge length as well.  So it's still a full caliber high velocity battle rifle cartridge...  Primary benefits of .276 P or .280 B vs .308 are higher velocity, flatter shooting, and reduced recoil...  Primary drawbacks of these higher velocity, necked down rounds is reduced barrel life due to increase throat erosion, which is of concern in a MG role...
http://wintersoldier2008.typepad.com/summer_patriot_winter_sol/2011/12/for-those-who-think-that-the-280-british-and-the-276-pedersen-were-pipsqueak-cartridges-in-compariso.html

Personally, I find the 5.56 FN Minimi/M249 SAW to be a greater aberration than the M4 in modern military use...  A true intermediate SAW capable of barrier penetration but lighter than .308 would be a great asset to troops, the M240 .308 MGs are considered medium machine guns...  And to my knowledge the Mk48 in .308 that weighs 2 lbs more than M249 (both FN Mini variants) is only available to socom -- ammo weigh-wise even with the lighter weapon, the problem still exists.

So, I'm more a fan of true intermediate calibers for the modern battlefield if you want one weapon capable of engaging both near and far -- the 7.62x45 Czech that the VZ58's predecessor, the Vz52 was designed for, is one of several options including 6x48 UIAC, .270/.280 british (which you mention as main competitor to .308 for NATO adoption), etc.  The VZ58, early prototypes, was also originally designed for the 7.62x45 Czech cartridge.

In regard to US Ordinance, weapon development has always been a problem.  The expiration of the Clinton AWB and adoption of ARs and accessories in large quantities by US civilians has played a tremendous role in allowing private companies to develop off the rack solutions to issues plaguing our military's primary small arm.  No doubt a tremendous soldier's number of lives have been saved by the US consumer demanding the best...

[RSR]

Not sure that scrub brush attachment is milspec...

Throughout the 80s, 90s, and even into the early 2000s/GWOT, it wasn't uncommon for America's finest, including Special Operations soldiers, to attach accessories to their M16s/4s with duct tape, unfortunately.  First sopmod kit came about mid-90s I believe.  Note my preceding comment on the expiration of the Clinton AWB.
Regardless of milspec, high speed tape is always authentic...

Lol. Have you not paid attention to the design on the SR762? Or the SR556?

AR's blow up or will lot run in water? That is complete nonsense. Mine has been soaking wet on a number of occasions and it shoots without any problems. Do you think the SEALs use Mk12s and Mk18s because they don't work in wet environments? No. I am fairly sure they dunk them in the ocean just like all of their other guns and those are both AR designs.

Speaking of the Mk18 mod 2....It is also used by the U.S. Coast Guard's Tactical Law Enforcement Teams, Maritime Safety and Security Teams, and Maritime Security Response Team and the United States Navy's Explosive Ordnance Disposal (EOD) Operators. It is also used by Marine Force Recon's CQB operators, and is in most cases the standard weapons of choice for said operators. Do you think those guys do not get them wet?? Surely the US Navy and US Coast Guard are never around water.

ARs don't penetrate urban barriers? Have you shot an AR loaded with M855 SS109 in this lifetime??

ARs won't run dirty? More nonsense. See the mud test above. Without crazy conditions like those I have gone months without cleaning my AR and it runs without any hangups whatsoever. If finished in Black T or RF85, they even run without lube (as in completely dry).

DI ARs can explode the upper receiver if water is in the gas system. 
Any AR with standard buffer tube extension w/ one hole on rear face cannot properly if under water.
Any .22 cal gun w/ bullet in chamber can have a water seal in the barrel which can result in barrel bursting.
You are correct that piston ARs have less problems with water in action, but that system comes with weight and accuracy penalties vs DI. 
Note my earlier comments re: water in the system to MeatAxe's comments as well. 

One round of 5.56 will not penetrate as well as one round of 7.62x39 against most intermediate barriers, that's a fact. 

No weapon should be intentionally abused like not cleaning or running without lube.  It's like running your car engine with no oil or the cheapest oil.  Just b/c you can doesn't mean you should.  And no dry films and special coatings do not provide same level of protection to metal on metal wear as they would with the addition of lube.

As with most things, there's tradeoffs.  Understand them and decide accordingly.  Don't reject them b/c you don't like the facts.