Archive for the 'AR-15s' Category

Housekeeping Note: Herschel is offline this week. We’re certain that the quality of the posts will suffer, but the quality of the discussion in the comments doesn’t have to!

Source:

…After the American experience in Korea, where servicemen faced massed assault from Chinese forces, it was decided that the World War II workhorse M1 Garand rifle was no longer adequate; its low capacity and lack of full automatic fire hamstrung U.S. troops.

The Pentagon wanted a new rifle. Around the same time, there was a push among NATO members to standardize a rifle caliber to simplify wartime logistics. American design philosophies dominated both, and the Army’s parochial Ordnance Corps dominated the discussion on design. Ordnance Corps officers clung to the popular myth of the heroic American rifleman, who wins the day with a few well-aimed, long-ranged shots from a full-power rifle.

Thus, the M14 was born, as well as the new NATO bullet, 7.62x51mm. But everyone soon discovered the difficulty of controlling full-caliber rifles on full-auto; 7.62 NATO weapons quickly turned into anti-aircraft guns in longer automatic bursts, rendering the feature ineffective. These experiences were supported by the results of Project SALVO, a Pentagon research project to develop next-generation infantry weapons. SALVO concluded that a smaller bullet traveling at high velocity would be as lethal, if not more so, than big calibers like 7.62 NATO; the SALVO report recommended that the Pentagon should adopt a little-known gun called the AR-15, designed by ArmaLite engineer Eugene Stoner, and based off his earlier file design for the AR-10.

The AR-15 was unlike anything seen before: It was constructed of forged aluminum and plastics, used a direct impingement gas operating system, and was chambered in the new 5.56X45mm cartridge. It was the antithesis of the M14. Naturally, the Ordnance Corps hated it, and moved to kill the project by resorting to testing practices and emulation that were ultimately unfair to the AR-15. The weapon languished in design committee as Army traditionalists butted heads with Robert McNamara and his RAND Corporation  “whiz kids.”

The article goes on to discuss the interesting history of the AR-15 type platform.

This all may be a bit overdone in my opinion.  Drop a BCG in and run the gun.  If you have problems, note that and get another BCG.  Well made guns will work right.

I like Battle Arms Development BCGs and Radian Raptor charging handles.  The two taken together make the parts feel like glass.

But not all BCGs are created equal.

Source.

The rate of the rifling twist inside a rifle barrel would seem to be mostly a gun thing as opposed to an ammunition thing. However, for ammunition to shoot accurately, the bullet must be stabilized, and for a bullet to be stabilized, the rifling rate-of-twist must be compatible with the bullet’s length and velocity. This means that twist rate is very important to ammunition, and it is why the Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) establishes standards for twist rates as they relate to arms and ammunition.

This is a good thing. It’s why when you purchase ammunition for your firearm, you can expect that ammunition to shoot at least reasonably well. Most ammunition manufacturers make ammunition to SAAMI specifications, which means the bullets—at their launch velocity—will mesh well with the rifling-twist rate of the gun for which you bought them. It can, however, be a bad thing, as history has shown.

In 1955, Remington introduced the .244 Rem. cartridge. It fired a .244-caliber bullet and had a stipulated rifling-twist rate of one turn in 12 inches (1:12). The cartridge worked great with bullets in the 55- to 90-grain weight range. However, that same year Winchester introduced the .243 Win. (I’m betting Winchester had a spy inside Remington.) The .243 Win. also fired a .244-caliber bullet, but Winchester very wisely specified a 1:10-inch twist rate for the rifling. This meant Winchester’s 6 mm cartridge could handle heavier—longer—bullets of 100 grains. Both cartridges became popular, but the .243 Win. won the battle even though it was not quite as fast as the .244. Why? Twist rate. Eight years later Remington tried to save its .244 by reintroducing it as the 6 mm Rem. and tightening the twist rate from 1:12- to 1:9-inch. This allowed the cartridge to better compete with the .243 Win. But, it was too late.

Remington has always seemed a bit late to the game.

Almost the exact same thing happened to Remington again in 2008. That’s the year Hornady introduced the 6.5 Creedmoor, which fired a .264-caliber bullet out of a cartridge case similar in size to the .260 Rem. Remington had introduced the .260 in 1997 and it had become a very popular cartridge for long-range target shooting and hunting. However, Remington stipulated a 1:9-inch twist rate for the .260, while Hornady stipulated a 1:8-inch twist for the Creedmoor. Because of the Creedmoor’s ability to handle longer, more aerodynamic bullets, Remington got twisted out of the conversation again.

I’m not really sure that’s completely why – I think free bore had something to do with it too, maybe a lot more things.  The folks at Hornady don’t appear to like free bore at all and want the bullet as close to the leade as possible, just at the rifling, in order to avoid bullet deformation.  That’s one reason they don’t like the 300 Win Mag (stock ammo, not reloaders) and do like their own 300 PRC.

While all this was going on, developments with what is now the most popular rifle cartridge in America were struggling through another twisted situation. In 1964, the .223 Rem.—yep, here we go with Remington yet again—was introduced. It was initially famous as the cartridge of the AR-15 and, in 5.56×45 mm form (which isn’t identical) as the cartridge of the military’s M16. The .223 Rem. had a specified twist rate of 1:12 inches, which was about perfect for a 55-grain bullet at 3,200 fps.

But, in the early 1980s, the 5.56 NATO cartridge was standardized. Externally, the cartridge-case dimensions of the .223 Rem. and the 5.56 NATO are identical, but the chambers are different, and the 5.56 NATO is loaded to higher pressures. Also, it is a military cartridge for which there are no SAAMI specifications. Initially standardized with a 62-grain bullet, 5.56 NATO rifles have a much faster 1:7-inch twist rate. This allowed the 5.56 NATO to stabilize longer bullets that were heavier and shot flatter. Aficionados of the .223 Rem. caught on and started re-barreling .223 Rem. rifles with faster-twist barrels and loading their own ammo to take advantage of newer and longer bullets.

However, most ammunition for the .223 Rem. is still built to work with the original 1:12-inch twist rate. Why? Well, there are many, many thousands of .223 Rem. rifles out there with a 1:12-inch twist. If you have one of those and purchased ammo loaded with a bullet that needs a 1:8-inch twist, you’ll struggle to hit a snuff can at 100 yards. But, some ammo makers are now offering .223 Rem. ammo that needs the faster twist.

Rifle manufacturers are doing the same. For example, Savage initially used the slower twist rate for the .223 Rem., but by 1995 all Savage 110 rifles in .223 Rem. had a 1:9-inch twist. In 2007, Savage added a 1:7-inch-twist-rate barrel to several models, but when it entered the AR-15 market in 2017, the company settled on the 1:8-inch twist for its MSRs in .223 Rem. or 5.56 NATO.

Of course, factory .223 ammo designed for a 1:12-inch twist will shoot just fine in the faster 1:8- or 1:7-inch twist barrels and in 5.56 NATO rifles. (Do not shoot 5.56 NATO ammo in rifles chambered for the .223 Rem.) This is one of the reasons many modern AR-15-style rifles are chambered for the 5.56 NATO instead of the .223 Rem., and it’s also why many manufacturers now load 5.56 NATO ammo and sell it commercially. Some manufacturers also cut .223-caliber chambers to the .223 Wylde chamber to allow for the firing of both .223 Rem. and 5.56 NATO ammunition—more accurately in the case of .223 Rem. and safely in the case of 5.56 NATO.

Cartridge designers have now finally learned and are specifying fast twist rates when new cartridges are introduced. Just look at the 22 Nosler, 224 Valkyrie, 6 mm ARC, .277 SIG Fury; the list goes on. Today, longer, more aerodynamic bullets pushed through fast-twist barrels shoot flatter and hit harder at distance.

Tim Harmsen at Military Arms Channel did a video of an M-16 shooting in a 1:12 twist gun into ballistics gel, and other media, and it seemed to outperform the shorter barrels with tighter twist.

Anyway, it’s ironic that this discussion occurred the next day after we touched on these issues.  Also, in my AR-15 category there is a lot of discussion on ballistics and twist rate.  I won’t recapitulate it here.

Take all of this for what it’s worth.  He speaks it as gospel, and I suspect not much of it is.

I will remark that I very much like the performance of the 6mm ARC.  It’s a pure pleasure to shoot, without recoil noticeably stronger than the 5.56 and yet with vastly superior results.

Our friend Andy at Practical Accuracy has given us an awesome video on the use of 55 gr. bullets in a 7:1 twist barrel.

"Do you realize the bullet out of an AR-15 travels 5 times as rapidly as a bullet shot out of any other gun."

🐂💩 pic.twitter.com/cTS1B84wtS

— Rob Doar (@robdoar) August 30, 2022

Hey, I want one of them things!!!!!!

Demented old fool, or perhaps just reading from the script put in front of him by his handlers who want to perpetuate fear among idiots who don’t know how to Google muzzle velocity of 5.56mm (3250 FPS with a 20″ barrel and 55 gr.) versus say, 300 Win Mag (3290 FPS with 150 gr.).

H/T: The Gun Feed.

This is an extremely well-done video presentation.

News from Atlanta.

It looks to me like he was in retreat to cover and didn’t aim well or land any shots.  Too bad.  But at least the presence of the rifle made the assailants flee.

No one needs an AR-15 for self defense.  Tell that to the man who was just on the receiving end of 20+ rounds.

Or tell that to Stephen Bayezes.

Or tell that to the pregnant woman who used an AR-15 to defend her family.

No one actually needs an AR-15.

— Hillary Clinton (@HillaryClinton) June 3, 2022

Says the woman who strung out good men to die in Benghazi because it was inconvenient to admit to America why there were there in the first place.

By the way, I guess these men didn’t get Hillary’s message about AR-15s.

Speaking of AR-15s, I also guess this woman was glad to have hers around when she needed it.

Our buddy Andy at Practical Accuracy has some thoughts on the M4 replacement (Next Gen Squad Weapon) we’ve recently discussed.

Make sure to watch it all, and some of the comments are interesting too.

I have a rifle in which I installed a Radian Raptor charging handle and a Battle Arms Development BCG.  The two used together makes the action like glass.  I have no comment on which charging handle you choose – but I do recommend one of the models as you see fit.