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6.5 Grendel replacement round for the 5.56?

detroitmachinery

Aluminum
Joined
May 27, 2007
Location
Detroit, MI
I think this would be a perfect replacement round for the 5.56. It will fit the standard M-16 magazine, and has far greater muzzle energy. This round also has excellent long range accuracy. This is particularly well suited to Asscrackastan, and Iraq. Check out these ballistics http://en.wikipedia.org/wiki/6.5_Grendel The 7.62 is too long to fit in a M-16 mag, and it would also create allot of heat issues with a light weight assault rifle barrel. With 1950 fpe it has plenty of stopping power to drop drugged up BG's.
 
The grendel has issues of its own. The problem with rounds like the grendel is that compromise calibers rarely excel at anything. The Grendel does have a good accuracy reputation past 300 yards, but below 300 it is beat in almost every aspect by the 6.8 SPC. The 6.8 is a compromise caliber as well, and has its own issues. I feel the answer will be in the form of a new duty rifle, but not for a few years.
 
Did you read the web link? " Production rifles have consistently achieved sub–minute of arc (MOA) groups at test ranges out past 600 meters.[3]On March 6, 2006, Arne Brennan achieved a witnessed 1.198" group at 660 yards.[4] Similar accuracy was demonstrated at recent Blackwater Shootouts." This is what impressed me 1.2" at nearly 700 yards. This is 300 magnum accuracy out of a light recoil round. Where are the shortcomings?
 
That is more chance accuracy. How many groups were fired to get that. In other words, would you bet your life on it. At 1000 yards 7fps difference in vel is an inch of drop.
 
This is not designed to be a 1000 yard round. It is a far better round than the 5.56. Any assault rifle is mainly designed for shots under 300 yards. I think 4 less rounds per mag is a good trade off for the extra fpe, and stopping power. For 1000 yard shots, you reach for the Barrett M107 .50 cal. Would you bet your life on a 5.56?
 
The 1000 yd number was to match the 7 fps/1 inch drop. What the point was, how many groups of that size could you make in a row? How much would you bet on 2? Five 5-shot groups in a row going into .250 I would trust a lot more, and that is an unusual rifle. What will the standard issue rifle do? That is what you are defending your butt with.
A hevier caliber would help I understand, I'm building a .257 X 50mm(223 is 45mm) and I trust it much mort than a 223.
 
There is MUCH more to be read on the pro's & con's of this caliber compared to the 6.8 SPC.
Visit AR15.com to read all about them.
I own several AR-15's in all calibers. My favorite by far is the AR-10 (T) Carbine in the 7.62 X51mm (.308) The 16" match grade SS barrel will shoot a 168 grn. bullet as good as a 24" moly barrel out to 400 yards before it shows signs of loss of velocity due to the short barrel. My 24" .308 version in SS will shoot to 900 yards all day and still have the effective killing power when it reaches a body at that distance. I also have an AR Armalite version '(TU)' in the .300 Remington Short Action Ultra Mag (.300 RSAUM)which shares the same OAL as the .308 but is pushing a 180 grain bullet at 3000 fps to make it a 1200 yard sniper weapon system.
I think the bugs are worked out of the modern M4's but the anemic 55, 62, & 75 grain 5.56 X 45mm cartridge has met it's potential for stopping power based on velocities out of the different barrel length's, and bullet weights while attempting to penetrate layered clothing and structures / cover etc.
I personally see the .308 as a damn good cartridge and will be making it's comeback in the near military future. All of the hype the military went through to develop a "New Battle Rifle" in the plastic H&K cloned 'XM8' was typical of the Government dumping millions of dollars into a new rifle that shot the same limited 5.56 mm cartridge.
The ballistics of the .308 are barely short of the venerable .30-06 but in a short action, which is perfect for gas operated battle guns.
Not only that but the 7.62 X 51mm is an approved NATO cartridge as is the 9 mm. The US can't just go changing M-16's or M4's to the 6.8 SPC without remaining interchangeable with other 27 NATO countries. Sharing the same cartridges as our allies in the event of a war is how we lost the great stopping .45 cal except for special Ops.
SO while the 6.8 SPC sounds good, it is not the fix we need. Look to the special OPS community. They are still carrying the modernized M-14's because they trust they will stop what that 168 grain 7.62 will hit. They don't believe there should be a trade off on amount of rounds carried with stopping power.
 
As Yankee said, changing a NATO round is not as easy as it sounds.

The 5.56 x 45 may not be the ideal light rifle cartridge but you have to understand how it came to be, and put it into it's proper time perspective.

The militaries of several countries were looking toward a small caliber high velocity (SCHV) cartridge and weapon before WW II ended. At that time it was also felt by many that multiple projectile and flechette (darts) cartridges and a maximum effective distance of 300 to 500 yards were the answer to the relatively poor marksmanship of the average GI. In other words, put enough projectiles in the air and your target just might walk into one.

The adoption of the 7.62x51 in 1954 put many of the small caliber projects on the back burner but the outstanding Armalite rifles which were designed around a 222 Remington type cartridge prompted several high ranking military types to continue with the concept and the 5.56 was eventually adopted by the US and became a NATO standard.

As far back as the 1920s there were many civilian and military types who were pushing for 26, 27, and 28 caliber military weapons but the higher brass was determined to keep the US Service cartridge at 30 caliber and all of these projects were killed in one way or another. In the 1950s the UK developed a very good 28 caliber cartridge and proposed it as the new NATO standard but the US was such a dominant member that that idea was vetoed in favor of the 7.62.

We'll no doubt see a new military cartridge some day but things like this take years. And unfortunately, politics will probably again play a big role and the new standard will likely be some sort of compromise.

Ray
 
In my opinion, the 6 x 45 (6 mm/.223) would be the ideal "replacement" for the 5.56 NATO.

Same magazine, same bolt, same brass and puts out about 30% more energy than the 5.56.

If you follow what has happened to the M-16 and the 5.56 over the decades, it makes sense that they "think" they need a replacement. When the AR-15/M-16 was designed, it was designed with a 20" barrel to fire 55 grain bullets. Around 1984 the DOD decided that they were much more likely to be fighting in a desert than a jungle any more. That prompted a bunch of changes. They went to a 62 grain bullet, and by doing so, needed a quicker twist. After that, the sights no longer followed the trajectory of the old 55 grain bullets..........so....they came out with new sights. The heavier bullets made controlling the M-16 in full-auto impossible, so they went to a tri-burst selector. Then the big change! Now you already have a heavier bullet than the gun was designed to shoot, now let's shorten the barrel to 14.5". That make sense to all you guys, doesn't it?

That's where the 6 x 45 makes sense to me: Same powder capacity, but much more bore capacity to burn that powder in. The 6 x 45 would do a much better job with a 14.5" barrel than a 5.56.

I'm biased though, I have three 6 x 45's myself. I took a nice white-tail with one last fall, and have won more matches with the 6 x 45 than all my other guns put together.
 
Yankee;
As to Special Ops ,they still have grease guns and the Shoulder Recoiless last I knew. JABEZKIN
I was referring to the H&K USP45 and the Sig Sauer P220 when I mentioned the .45 cal.
I am a fan of the M-14 as that is what I used for a short time in the M21 SWS in Haiti & Panama in the '80's.
While I enjoy the Armalite in the AR-10 platform more than the M-14, It weighs more than the M-16 / M4. But the bullet can penetrate a block wall and still take out the Haji cowering on the other side. Additionally the 175 grain bullets for the 7.62 are getting the same accuracy as the old stand by load of 168 grains, and puts an ass kicking to the target.
It's been a while since I shot 3-gun comps as a SWAT sniper for Law Enforcement, but my spotter and I's backup rifle was the beautifully tuned AR-10 (T) because it shot the same cartridge as my Remington 700 BDL (Yes, back in the day that is what I was using).
One thing I dislike is in shooting comps, cowboy or tactical, is that the competitors downloaded their ammo for short range accuracy and faster follow up shots. Then they would claim that their great scores were consistant with the caliber of weapon they were using. When in reality the gas gun cartridges were loaded just hot enough to cycle the bolt with the adjustable gas system maxed out, and it was really obvious when the H&K MP-5 shooters were required to attach their suppressors and they had to change load marked mags to get the bolt to cycle.
I always used fully loaded tactical rounds because you practice with what you use on the street.
Ever shoot a .45 LC , 12 ga coach gun, or .45-70 Sharps that has been loaded for cowboy comps? There is almost NO recoil. I am not saying you are doing this with the 6.8, but I witnessed this happening at a comp a few years ago that I was not competing in. Sadly enough it was a Law Enforcement shooter more interested in winning the comp than training for a real life scenario.
I spoke with the SWAT commander about it but it fell on deaf, ignorant ears. He was more concerned with 'high scores' than preparing for the real battle that could come anyday.
Good topic Detroit.
 
I made a 6-shot .475 on a ruger, 3 inch barrel.
He was shooting 1oz slugs at the below the 1000fps limit, but they gave him #$^^%%^^^!!!
You can't fire full power loads was the reason he was asked to leave.
Cowboy action shooting, he didn't understand.
 
Cowboy action shooting, he didn't understand.

Yeah, some of those people know about as much about ballistics as the barracks ballisticians who said you could shoot a VC in the hand with an M16 and break all the bones up to his shoulder because the 5.56mm was so high velocity.
 
Quote Dtech -In my opinion, the 6 x 45 (6 mm/.223) would be the ideal "replacement" for the 5.56 NATO.

In the early 1970s the US tested several small 6mm cartridges, one of which was virtually identical to the 6 x 45. Needless to say it was not adopted and will probably not see the light of day again.

Center cartridge below. All shown are 6mm SAW (Squad Automatic Weapon) cartridge experimentals.

Ray

6SAW.jpg
 
Quote cheechako
"In the early 1970s the US tested several small 6mm cartridges, one of which was virtually identical to the 6 x 45. Needless to say it was not adopted and will probably not see the light of day again."

You're probably correct. Logic has little to nothing to do with these types of decisions with the DOD. I only said that if they were looking for a replacement for the 5.56 with a little more knock-down power, the 6 x 45 would be a good choice. Most likely will never be adopted.
 
I'm no expert, never claimed to be but 6mm seems a good choice.
Here in CT it's illegal to own a AK-47 in 7.62 x 39 but it's perfectly fine to own a AK-"74" in 5.45 x 39. Of course you can own a SKS in 7.62 here because it's not so evil looking.... but I digress.
I loved my CETME, but it's large, like the FAL they too suffer the weight issue, although I'd dig ripping it like the Pakistani's get to do.
 
Check out this ballistics chart. http://www.65grendel.com/graphics/grendelballistics.pdf At 1,000m the 144 grain 6.5 Grendel has 103 fpe more than a 7.62 with 147 grain slug. The huge BC advantage for the 6.5 tells the story, .587 BC for the 6.5 with 144 grain slug, .418 for the 7.62 NATO with 147 grain slug, and the 6.8 faired far worse with a BC of .340 with a 115 grain slug.

Another advantage of the 6.5 is the light recoil, about half that of a .308 NATO. A fully automatic M-16 with .308 would be a handful.
 








 
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