March 12, 2019
Photos by Mark Fingar
When I first learned Hornady was coming out with a long-action, .30-caliber magnum cartridge, the question that first came to mind was, Why?
It was a good question since the .300 Winchester Magnum (WM) is America’s top-selling, long-action cartridge. Then there’s the .30 Nosler, another great design for a very-low-drag (VLD) bullet. And we can’t forget the .300 Norma Magnum (NM) and .300 Remington Ultra Magnum (RUM) for those who want as much powder behind a .30-caliber bullet as possible. Surely, those cover all the demands from a .30- caliber.
The one glaring weakness in the .30-caliber magnum lineup is best highlighted by examining the requirement around which Hornady designed its new .300 Precision Rifle Cartridge (PRC). The requirement came from the U.S. Special Operations Command (SOCOM) which asked the industry for a cartridge that would give its snipers a 50-percent hit probability on a man-size target at 2,000 yards. The .300 PRC was developed by Hornady to be the answer.
We’ve been at war for 17 years and the handful of times that kind of range was necessary, snipers would typically walk rounds in on target until they got lucky. As a former sniper, I would argue that the expectation is unrealistic and any fractional performance gains achieved in its pursuit are not going to be worth the effort or expense.
That was my opinion before listening to a member of SOCOM involved in the requirement and hearing about the testing done for it. His response was not what I expected.
After taking a brief stroll down memory lane and reminiscing how fighting the war used to be, he went on to explain what war looks like now. It used to be unlikely that U.S. forces would encounter an enemy that could shoot accurately past 600 yards, crew-served and indirect-fire weapons notwithstanding. Now, it is quite common to face near-peer elements in some parts of the world.
The gentleman from SOCOM said that, on today’s battlefield, passing the forward line of troops meant you would most certainly get shot at. The only questions are: “What is going to get shot at you? And, how long it’ll take before it happens? The enemy has a lot of the same equipment we do, including night vision, thermal sights and even anti-tank missiles.
Under these conditions, SOCOM feels the best thing we can offer to protect our servicemen is to take a step back and put some distance between our enemy and us. No nation on earth produces rifleman like America. We teach our children to shoot and many, like myself, learn from our fathers at a young age. There is no shortage of rifle competitions where neophytes and seasoned veterans alike can hone their skills. To add, we have a firearms industry that’s home to a handful of brilliant minds that know how to design and manufacture the tools necessary for extreme performance. Taking advantage of that knowledge base is a marvelous strategic idea, and it makes me want to stand at attention just thinking about it.
Like any great idea, the application is always more difficult than coming up with the concept. The first cartridges to be evaluated were the big boys including .50 BMG, .416 Barrett, as well as the .375 and .408 CheyTac. The issues with those cartridges were that the host guns are simply huge and the ammunition is large and heavy. No sniper moves very far or very fast on the battlefield with an oversized rifle and enough ammo to feed it.
“P” is for Precision About this time, Hornady stepped forward with a project they had been working on for a while. The solution they presented, given the parameters outlined by SOCOM, was the .300 PRC, which is similar to other .30-caliber wildcats like Dave Tooley’s .30 Boo Boo, the .300 Accuracy International (AI) and the .30-375 Ruger.
There’s a reason the .300 PRC is very similar to those cartridges. Everyone was looking for a solution to the same problem and smart guys from different companies arrived at nearly the same conclusion.
For background, Tooley is a champion benchrest shooter who frequently competes out to 1,000 yards. Accuracy International developed their .300 AI cartridge in 2009 when SOCOM had some aggressive accuracy requirements of 1,500 meters for a long-range, sniper-rifle solicitation. AI didn’t think any of the cartridges then fielded could do what SOCOM wanted, so they pursued their own.
While the dimensions of these cartridges are all pretty similar, the throat length and throat diameter of the .300 PRC are tighter than any of the wildcats. This means you can safely chamber and fire .300 PRC ammunition in most .30-375 wildcats. It’s worth noting that the .300 PRC is a necked-down .375 Ruger, its parent case.
What makes the .300 PRC special is the combination of a standard magnum action with a heavy-for-caliber, VLD bullet. Hornady wanted to use a case head size of .532-inch to allow most long-action rifles to easily chamber this cartridge. When a shooter jumps to the larger .588-inch bolt face — as used in the .300 Norma — actions and other components become more expensive. By choosing the .532-inch bolt face, Hornady made it possible to rebarrel any .300 WM to .300 PRC.
With case head size selected, Hornady set about designing the rest of the cartridge for precision. In fact, many of the same principles used to create the 6.5 Creedmoor were used on the .300 PRC.
The freebore diameter is held to a snug .3088-inch. This means a .308 bullet, when chambered, is going to sit inside a hole that is only .0008-inch larger than the bullet. This is a key component for long-range accuracy in any cartridge because this shooting discipline relies on long and heavy bullets.
Bullets get pushed from the rear when a cartridge fires, so it’s easy for them to twist or yaw in the chamber prior to engaging the rifling. Should a bullet get crooked in the chamber before it hits the rifling, the bullet’s center of gravity gets forcibly moved when the bullet finally engages the rifling. In short, it gets slightly smashed into a new shape. Since there’s no way to predict what the new shape will be, accuracy is erratic when this happens.
The .300 WM suffers from this phenomenon the most. The freebore diameter on a .300 WM is a minimum .315-inch, as per SAAMI specs. Where the .300 PRC has only .0008-inch of slop, the .300 WM has .007-inch of slop. That’s an increase of 875 percent in freebore clearance, which illustrates the stark contrast between a precise cartridge and one that throws the proverbial hot dog down a hallway. If you have a .300 WM that struggles with VLD bullets, this is probably why.
The length of the .300 PRC is held to 3.7 inches maximum overall length, but it has a neck/shoulder junction closer to the case head than the .300 WM, even though the .300 PRC is about one-third of an inch longer overall. This neck and shoulder geometry design was no accident.
The .300 PRC is designed around a 225-grain bullet that enabled Hornady to keep as much projectile as possible out of the case. This is essential for consistent long-range performance. The .300 PRC is the only .30-caliber magnum to be designed around this principle.
A perfectly designed case would have the top of the bullet’s boattail sitting right at the case’s neck and shoulder junction. This keeps the bullet’s bearing surface above the joint, which simplifies reloading procedures, but also keeps the bullet out of the powder column.
When a bullet sits inside the powder column, it can be bent or pushed off-axis, making it unstable in flight or forcing the bullet to yaw prior to engaging the rifling. Just about every .30-caliber magnum puts a lot of bullet in the case. The .300 PRC was designed to specifically avoid this problem. While a tight freebore diameter can mitigate the yawing effect of putting a bullet in the powder column, there is no remedy for bending a bullet. This is why the .300 PRC combines both a tight freebore while still refusing to put the bullet inside the powder column. The results are spectacular.
Given the longer 3.7-inch length, which still fits easily in AICS-pattern detachable-box magazines and most internal magazines, the .300 PRC puts as much powder behind a VLD bullet as possible while still keeping the bullet out of the case. This means velocity should be high, accuracy exceptional, and all with a barrel life similar to a .300 WM since the .300 PRC uses a pinch more powder.
Going Long with the .300 PRC
I had to see first-hand just how the .300 PRC performed at really long distances, so I had Mile High Shooting Accessories (milehighshooting.com) chamber a barrel in it for my Accuracy International AXMC. I took that rifle to the FTW Ranch (ftwsaam.com) in Texas for evaluation and then again to a friend’s training facility in Idaho for a few more days of study.
During the Idaho visit, I had the opportunity to shoot the cartridge out to 2,349 yards. The hit percentage at that distance using factory ammunition on an 18-inch wide by 30-inch tall steel plate was about 20 percent. That distance is asking a lot of any .30-caliber offering, and I thought it would be impossible with factory ammunition. However, hits were still manageable — even with a slow and changing wind.
The time at FTW allowed me and two friends to shoot at a 32-inch circular steel target at 1,600 yards. The hit rate jumped to 60 to 70 percent with the same rifle and the same factory ammunition. In fact, the first five-shot group out of that barrel with factory ammo measured a scant .53 inches at 100 yards.
The .300 PRC offers a level of performance unparalleled by any other .30-caliber cartridge. Readily available factory ammunition pushes Hornady’s 225-grain ELD-M at 2,880 feet per second, keeping it supersonic to almost 2,000 yards at the 3,000-foot elevation I tested. Folks, you won’t find a more shooter- and rifle-friendly, .30-caliber magnum than this one.
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