Originally Posted by climate17
I'm going to go the other way with this. In order for you to get a weapon as good as the scar in an AR 15 you need one of these guns LWRCI M6 series (1800-2400) a POF (2200-2600) or a hk mr556 (3295) so any one talking about how there stock AR stacks up doesn't have one of these, and they probably aren't even gas piston AR's like the ones I mentioned are. So they aren't comparing apples with apples. The answer is yes scars are worth every penny, no matter if it's the 16 or 17. They ARE worth it.
With respect to stock AR platforms being as good as stock M6 or MR556A1, it would be helpful to quantify what you mean by "as good as". Are we talking reliability, weight, balance, ergonomics, access to plentiful replacement parts and accessories, or something else? Who leaves any fighting rifle stock?
How reliable is reliable enough?
John Moses Browning created a M1917 machine gun that fired for something like 45 minutes without cessation of firing or failure of any kind, but the gun weighed more than a M2HB machine gun.
I'm not willing to sacrifice 2 pounds of weight, the equivalent of a 30 round stick and all the accessories on my rifle, for more reliability than I already have.
I'm a civilian and I don't jump out of airplanes, assault any beaches, or wade through any mud pits. If you are SOF, infantry, or law enforcement, I understand the need for a heavy duty carbine that is more tolerant of filth. In the worst realistic scenario I can think of, I might have to patrol the neighborhood after a hurricane or flood. In all honesty, it's improbable that the carbine will see use much further than my front doorstep. For those realistic use scenarios, the weight, balance, and pointability features are more important to me than ultimate reliability.
From experience, my personal AR's have had very few problems not related to crappy or damaged USGI magazines and no problems that couldn't be immediately corrected. I do have to replace parts and use quality magazines and ammo, but the gun functions as designed. If that were not the case, I would not use it.
All piston guns based on the AR platform are heavier than DI guns with one exception that I know of. All piston guns designed from the ground up as piston guns are heavier than DI guns period because they are designed to be machine guns. Part of what made the M1917 machine gun reliable was the weight of the bolt, its design, and method of operation. All current piston combat rifles and carbines that an operator will carry in his or her hands for an extended length of time have been built for full auto. The requirements for full auto are different than for semi-auto. Lighter weight parts could be made, but it would adversely affect cost, service life, and/or reliability.
M6 is slightly lighter than the SCAR 16S, the MR556A1 weighs almost as much as a loaded SCAR 17S, and the POF is slightly lighter than an unloaded SCAR 17S. All weapons listed are equivalent to or heavier than a loaded 6721 with accessories. The MR556A1 is so heavy it's more near a DMR or battle rifle than it is a carbine. HK should have put their rail system on a diet. You can easily get yourself into an 11 pound gun with that platform. The M1 rifle weighs between 10 and 11 pounds, given different stock materials. Not my cup of tea for something I actually have to carry.
All piston guns apart from bullpups have the weight of the piston mechanism in front of or near the front of the operator's support hand. Humans, to include Navy SEAL's and Delta Force, experience muscle fatigue. Physical fitness helps, but all humans fatigue and dexterity suffers.
The DI platform places more weight nearer to the operator's fire control hand. Any static weight in front of or behind your hands you'll constantly fight against as long as the weapon is in your hands. After about three hours of actually holding an 8 to 9 pound gun in my hands and ready to use, I determined that heavy and/or muzzle heavy guns were not for me. Slings and weight distribution help, but all other factors being equal a lighter weapon with better dynamic weight distribution will serve you better in situations where movement is involved and/or mother earth isn't helping you hold your weapon.
Shoulder your fully equipped M6, MR556A1, or SCAR 16S with one hand and see how long you can keep it there. Then repeat the test with a 6720 or other pencil barrel AR. Keep the weapon shouldered in a firing position and pointed at a target like a screw on a wall-mounted light switch from say 15-25 feet. Let me know how that goes.
There isn't much difference between the M6, MR556A1, SCAR 16S, and a Colt. The SCAR requires an aftermarket charging handle to clear optics and so do the AR designs. I guess the manufacturers of the "improved" weapons didn't take charging the weapon into account. Of all the rifles listed, only the LWRC has true ambi controls from the factory. If mirrored controls are important, then LWRC has the best controls. The POF's only have a bolt release on the ejection port side, if memory serves. The SCAR has ambi mag release and selector lever, but no ambi bolt release. If you leave your charging handle on the left hand side, that isn't a problem. I like not having to leave fire control for bolt manipulations. MagPul provides that functionality on a stock Colt for less than 20 dollars.
I've never had a problem with reciprocating charging handles but some people don't like them. I think it's a useful feature for malfunction clearing, but to each his own.
All the other designs except the Colt have fold down front sights. I don't like crap in the way of my red dot. Perhaps it is simpler, but it isn't ideal. If Colt wanted to improve the 6720, they'd make the carbine more optics friendly with a dovetail gas block with sling mounts and a pic rail below for a light in lieu of the stupid bayonet lug so no rail system would be necessary.
Parts and Accessories:
While all the lights, lasers, and optics work with all aforementioned platforms, the continuous optics rails of the piston platforms are better than the Colt. The SCAR 16S has the best side rail layout, in my opinion, and it still has too much rail. I just think it's dumb to have pic rail where your hand goes. I've never seen anybody with half a clue mount a light or other accessory, apart from a sling mount, on a side rail where they have to place their support hand. It looks really cool, but it serves no purpose. The POF, LWRC, and MR556A1 all have this cool and useless feature that adds needless weight and bulk.
All of the aforementioned platforms have proprietary parts that are not present in the DI guns. Most are more expensive than parts for the DI guns and availability may be an issue.
For users who require full auto and go over the beach, the "better" guns may be "better". To me, they're all just heavier, have poorer balance, are more complicated, and much more expensive.
If Colt wanted to make the 6720 "better", they could do the following:
1. Dovetail gas block with side sling mounts and bottom picatinny rail for a folding front sight and weapon light
2. Rugged plastic lower receiver with steel or aluminum reinforcement where necessary to reduce weight
3. Better trigger
4. Full ambi controls
5. MagPul CTR stock and MOE or MIAD grip
6. CHF barrel with vortex style flash suppressor EDM'ed into the barrel versus threading the muzzle
7. Nickel-Boron plating for the bolt, carrier, and barrel extension
If Colt did all that to their 6720 and charged no more than perhaps 1500 for it, I think you'd be hard pressed to justify the weight and expense of a piston gun if you were not a government user.