The AR thead

[Nick M]

I can't think of why not. If you are young and coin is tight, save up. There is no better short range (300 meters and in) to get. If you think the direct impingement can foul the chamber, you are right. It can if you never clean it. If you want, a great many AR makers now offer a piston system option on their upper. I don't recomend it. I recomend a high quality upper. It doesn't have to cost as much as Wilson Combat, but they are worth it. You also don't have to put up with the 5.56 down range energy, or lack thereof. There are quite a few larger calibers. The number 2 seller right now after the 5.56 is my 6.8 SPC I have mentioned. .270 and .280 were original combat cartrideges that didn't get adopted because of the two great wars and existing platforms that got reused for logistical ease. Well the '06 was used for the long range trench warfare, and it does it well. The M1 was in '06 was the logistic carrover.

Its sort of rival, the 6.5 Grendel isn't really a rival. They are apples to oranges. The 6.5 isn't very good in a 16 inch barrel, yet it accels in a 24 inch barrel. Better than a long range 7.62 x 51 even when out past 600 meters.

The .458 socom cartridge is rare in terms of available ammo. That cartridge is a lot like the old 45-70. A huge whallop in the AR platform. When the Greek style riots start, if Obama is reelected, will happen when we go broke (sooner than later). This will make them wish they didn't try to torch your home. Share your story and experience.

 

[Nick M]

[video=youtube;MqGxwpOBNrc]http://www.youtube.com/watch?v=MqGxwpOBNrc[/video]

Part two shows penetration or knockdown power. That is where the 5.56 fails. It just isn't very big.That is why the 6.8 is what you should be looking at. 110 gr round at 2650-2700 fps, yet can still be controlled due to the design of the rifle.

 

[TheNewRed]

Pictured below is My AR, and my cousins standard AK. I built both of them, my AR is pretty plain jane besides the typical funiture bolt ons. It has changed a bit since the picture, i have added a 2X magnified Barsaka red dot, and did a pretty decent trigger job on it( Installed the JP enterprises yellow spring kit, and polished up the assembly really good). The Ak has hand rivited, its was assembled from a romanian kit i had lying around, and an Ohio Ordinance Receiver. xBoth guns are deadly accurate within 50Yds, and just recently i switched to the PMC "X-Tac" ammo with exceptional results. I dont have any future plans for my gun, i love it the way it is. Ill post some more recent pics of both when i get some taken.

 

[CTsupra]

Part two shows penetration or knockdown power. That is where the 5.56 fails. It just isn't very big.That is why the 6.8 is what you should be looking at. 110 gr round at 2650-2700 fps, yet can still be controlled due to the design of the rifle.

For military fmj rounds such as m193 or m855, sure. Modern personal defense rounds are a different story, and then there is the m855A1 which fixes the problem. 6.8 will never catch on completely, or replace 5.56 on the battlefield. May catch on for LE depts.


http://wstiac.alionscience.com/pdf/WQV8N1_ART01.pdf <------- The problem with m193 and m855

 

[Poodles]

Quality AR's are self cleaning (no, really, they are). The issue with failures were with the original M16's not being chromed and said to be mantainence free. While they are self cleaning, they do need lubrication.

Caliber choice should be based on availability IMHO. While some of the modern new calibers are better at certain jobs, cost of the ammo makes them a poor choice. The issue with the 5.56 in military use is because the rules on ammo design. One can easily buy hollowpoints that the military can't officially use...

While I like the AK better (it's cheaper and more durable), the AR is far more comfortable in every way.

The biggest draw with the AR platform is that it can be built for nearly any use, and you can have different uppers to do different jobs or use different calibers.

I will say that a cheap AK is usually perfectly fine, but a cheap AR is generally shit. There's a lot of companies and people making some pretty terrible AR's out there, while you can buy import AK's that where designed for military use. This is not to say that good bargains don't exist.

Oh, also, if you buy the upper and lower seperately, you don't have to pay the taxes (and yes it's perfectly legal to do).

 

[Nick M]

For military fmj rounds such as m193 or m855, sure. Modern personal defense rounds are a different story, and then there is the m855A1 which fixes the problem. 6.8 will never catch on completely, or replace 5.56 on the battlefield. May catch on for LE depts.


http://wstiac.alionscience.com/pdf/WQV8N1_ART01.pdf <------- The problem with m193 and m855

It is better as a combat round than home defense because the bigger the bullet, the deeper the penetration. Small and high speed penetrates less. Anyway, the 6.8 was looked at, but the logistics of a running change during war are hard to deal with. Just like the last time it was done with the M16. I like idea of the M855A1. I have all copper myself, the TSX from Barnes. I also have a bunch of OTM because of the low cost. But the all copper holds its mass better yet still expands. So it penetrates and has a large wound from expansion. Great idea on the A1.

More reading.

http://www.marinecorpstimes.com/news/2010/03/marine_ammo_031010w/

Before Marines in Afghanistan received enhanced 5.56mm rounds last month, an influential four-star general advocated behind the scenes for an option that packs even more punch: 6.8mm ammunition.

Three sources with knowledge of the Marine Corps&#8217; acquisitions process confirmed Gen. James Mattis&#8217; interest in the 6.8mm round, saying the head of Joint Forces Command in Norfolk, Va., lobbied for it as recently as December while pushing broadly for better service-rifle ammo.
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http://demigodllc.com/articles/6.8-mm-spc-cartridge-history-development-hornady-stag-arms-carbine/

Troubling reports about 5.56's performance were coming back from the field. Several soldiers had been killed or wounded by Taliban fighters who had already been shot multiple times by the Americans' 5.56 M4 carbines. These failures to incapacitate spurred the 5th Special Forces Group (SFG) to design an "Enhanced Rifle Cartridge" (ERC) to outperform 5.45x39mm, 5.56, 5.8x42mm and 7.62x39mm. MSG Steve Holland (5th SFG (A)) and Cris Murray of the U.S. Army Marksmanship Unit (USAMU) led the ERC project to provide optimum terminal performance from an M4 with minimal changes to the weapon. Troy Lawton (Chief Ballistics Technician) and Cris Murray (Service Rifle and R&D Gunsmith) of the USAMU assisted in developing loads, and built the rifles for the ERC project.

Cartridge assessment began with the 6mm PPC case, necked up to 6.5mm. The 5th SFG soon discarded the fat PPC case due to poor magazine capacity and insufficient reliability in the M4. Their attention then turned to the .30 Remington case, which is essentially a rimless .30-30 Winchester. Its head and body diameters are larger than 5.56 (0.378 inch), but smaller than 7.62x39mm (0.445 inch). This thoroughly obsolete cartridge was chosen as the parent case because its smaller head diameter (0.422 inch) required less metal to be cut from the bolt head compared to the PPC or 7.62x39mm cases, which improves bolt service life. Several rebated-rim prototypes were created with an SPC body but 5.56's rim (0.378 inch) to utilize unmodified M4 bolts. After trials, it was clear the full-diameter rim helped extraction as compared to the rebated rim design.

Once the case dimensions were tweaked to fit and work in M4-compatible magazines, the project team quickly turned their attention to bore size. Derivative wildcats from 5.56mm to up 7.62mm diameter shooting bullets from 90 to 140 grains were subjected to a battery of tests, and a sweet spot emerged. The 6.5mm bullets showed the best accuracy and the 7mm bullets were the most destructive, but the 0.277-inch bullets showed almost the same accuracy and trajectory as the 6.5mm and almost the terminal performance of the 7mm. When necked down to 0.277-inch and shooting 115-grain bullets, it provided the best combination of combat accuracy, reliability and terminal performance for up to 500 meter engagements. This cartridge was deemed 6.8 Remington Special Purpose Cartridge (SPC), because 0.277 inch is 6.8mm in metric and .30 Remington provided the parent case.....

Based on their experience with 7.62x39mm, the project team set a velocity goal of 200fps faster than the AK-47 ammunition from the same barrel length, with a projectile that provided a better ballistic coefficient (BC) and terminal performance. This was achieved very soon into the project using Sierra 115-grain and Hornady 110-grain Open-Tip Match (OTM) bullets. Using Ramshot 1660 powder for initial development, the team easily exceeded the 200fps goal. Shooting from an 18-inch SPR barrel, these loads shot 2635 to 2650fps, 300fps faster than the AK-47.

Unlike military-industrial-complex programs such as the XM-8, the ERC project was driven directly by Special Forces shooters at the spear's tip-- men who had been on the giving and receiving ends of fire. The 6.8 SPC was developed with less than $5,000 initial investment of government funds; later development costs were paid for by industry. This is in stark contrast to top-down "next generation" programs costing the tax-payers millions and rarely producing usable weapons systems.

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The second link is about 15 non full pages with lots of good information.

edit: not to make this a 6.8 SPC thread, I just think it is a really good all around cartridge.

edit 2: http://68forums.com/forums/showthread.php?18774-Remington-6.8-SPC-Guide.&p=187685#post187685

Info on the 6.8