This 300 PRC is Hornady’s Spartan response to going longer and hitting harder, so check out these handloads for the new .300 Precision Rifle Cartridge. I’ve been working with the new .300 PRC since Hornady introduced it in 2018, and after feeding a couple of rifles a steady diet of factory loads I was ready to try my hand at improving an already stellar cartridge with a few handloads.
What’s the point for the 300 PRC? Specifically, it addresses some issues with already-existing cartridges and the guns that shoot them. The .300 PRC, a new offering from Hornady, was designed to improve ballistic performance over the .300 Winchester Magnum, which has been a long-time favorite for military snipers. According to Bryan James, Barrett’s VP of Sales, the .300 PRC MRAD was built “specifically at the request of the U.S. Department of Defense, in a cooperative effort with Hornady.”
“The .300 PRC is supersonic at 1,600 yards, well past the .300 WM’s 1,300 yards with a heavier bullet,” James said. (225-grain versus-190 grain). “It also has less drop at 1,000 yards (7.46 mils) versus the .300 WM (8.15 mils), and more energy (1,314 ft. lbs. versus 837 ft. lbs.) Currently, DoD military customers have taken delivery of multiple shipments of the .300 PRC MRAD with a 100 percent acceptance rate, James added.
Readers may wonder why the .300 PRC exists at all, with the multitude of .30 caliber magnums already in existence. The .300 PRC fixes the problems associated with the .300 Win Mag’s long SAAMI spec throat of 0.315, and the cartridge’s short neck. When compared to the .300 PRC, shooting the .300 Win Mag is “like throwing a hotdog down a hallway,” Ruger’s Mark Gurney said, which is a pretty loose fit for a cartridge that’s used in a precision role. The 300 PRC also solves the problematic bullet seating position out of the case body where it intrudes into the powder column.
Early Rounds w/ .300 PRC MRAD
I got my first introduction to the MRAD in .300 PRC was during Athlon Outdoors’ writer Rendezvous in late 2018. Pounding steel targets out to 1,000 yards in the crisp Montana air was a cinch. Back home in Tennessee a few months later, I made the 45-minute drive to Barrett’s headquarters and picked up a new MRAD that had just rolled off the production line. That afternoon I mounted an Eotech Vudu 3.5-18x scope in an Eotech claw mount and headed to the range.
Shooting from a solid bench, I put 10 rounds each of the two available Hornady commercial loads across the Skyscreens of an Oehler 35P chronograph. The 212-grain ELD-X hunting load averaged 2,834 fps, with a standard deviation of 19 fps. The heavier 225-grain ELD Match load averaged 2,807 fps, with an SD of 18 fps.
Letting the gun cool for a few minutes, I loaded up 10 rounds of the ELD-X load and braced the rifle on solid front and rear bags. At 100 yards, I fired several 5-shot groups over the next hour, with the smallest measuring 1.383-inch. This load tended to group three or four bullets into tight clusters that shared the same ragged hole… with a frustrating outlier or two.
Switching to the 225-Grain ELD Match load, I followed the same routine. The smallest group measured 0.920-inch.
A few days later, I got my hands on one box of Hornady’s new .300 PRC TAP ammo that’s loaded for military and law enforcement. This TAP round uses the 225-grain ELD Match bullet, but it’s loaded hotter. With the limited amount of ammo, I fired three 5-shot groups at 100 yards, a single 3-shot group at 300, and sent the remaining two across the chronograph. Those two shots clocked an average of 2,893 fps, with only 3 fps separating the two shots. Not a very good data set, but it verified what I had been told about the load being about 80 fps faster than the commercial 225-grain load. The smallest 100-yard group measured 1.015-inch, just under 1 MOA.
A few months later I spent the better part of a week at FTW Ranch in Texas with a Ruger Precision Rifle chambered in .300 PRC in my hands. I got to put a lot of factory rounds down range, and topped it all off by ringing steel at 2,100 yards.
Home Brew Handloads
When I got back home to Tennessee, I wanted to sort this rifle out and find handloads that would equal or better what I had found with factory loads. I had an ample supply of once-fired Hornady brass from two different rifles, so I set up my Hornady dies to bump the case should back 0.001 using a fired case from the Ruger Precision Rifle I was shooting. I used a set of calipers to measure from the case head to a datum point on the shoulder. Measuring a fired case from the rifle’s chamber, I compared it to a resized case from a set of Hornady Match Grade dies set to cam over on the shell holder. That setting produced a shoulder set-back of 0.010 of an inch, which was more than desired. I backed off the resizing die until I got the desired 0.001-inch shoulder set-back.
After resizing all of the cases on hand, I used an RCBS 3-Way case trimmer head on a RCBS Trim Master to uniform cases back to 2.565 inches.
Next, I used a Hornady bullet OAL Gauge to find bullet-to-camber contact for several bullets. Maximum magazine length is 3.740 inches, so I quickly learned that I would be forced to jump heavier bullets a significant distance to contact with the lands for several of the bullets used. Typically, the heavier the bullet the longer the jump when limiting overall length to maximum magazine length. To get an idea of overall loaded cartridge lengths with various bullets seated to just touch the chamber throat, check out the accompanying chart.
The logical progression for testing bullets for this rifle is to divide them into two categories; those that can be seated to out to the chamber throat, and those that can’t while fitting within the magazine. For the purposes of this article, we’ll focus on bullets that can fit within the magazine and contact the throat. In addition, bullets were seated to allow 0.010 jump-to-contact with the chamber throat. Owing to time constraints, two powders were selected for testing. All bullets that made the preliminary cut were loaded with starting loads of Retumbo and H1000, and ignited with Federal Magnum Large Rifle primers. Five rounds for each load were fired at 100 yards while velocity was recorded 10 feet from the muzzle.
.300 PRC Starting Loads
| Bullet | Powder | Velocity | Accuracy |
| Sierra Match King 220-gr. | 70.9 gr. H1000 | 2,684 | 0.507 |
| Sierra Match King 220-gr. | 70.8 gr. Retumbo | 2,604 | 0.642 |
| Federal Terminal Ascent 200 gr. | 75.3 gr. H1000 | 2,910 | 1.751 |
| Federal Terminal Ascent 200 gr. | 75.3 gr. Retumbo | 2,777 | 0.680 |
| Berger Long Range Target 208 gr. | 72.0 gr. H1000 | 2,720 | 0.523 |
| Berger Long Range Target 208 gr. | 72.8 gr. Retumbo | 2,637 | 0.774 |
| Hornady BTHP 225 gr. | 70.2 gr. H1000 | 2,656 | 0.608 |
| Hornady BTHP 225 gr. | 71.5 gr. Retumbo | 2,606 | 0.551 |
Weeding out the less accurate starting loads, each were increased until pressure signs were indicated or maximum loads were reached. Typically, the fastest most accurate load with low standard deviation is selected as a working load.
Among the previously covered load combinations, 79.2 grains of Retumbo driving a 208-grain Berger Long Range Target bullet at 2,918 fps proved the be the pet load for this rifle. Several groups averaged 0.536 inches at 100 yards.
Checking with industry contacts I got some preliminary load data that indicated that VihtaVuori N570 was yielding good accuracy with heavier bullets. My initial load of 76.3 grains pushing a 245-grain Berger left the muzzle at 2,658 fps. I took this all the way 82.0 grains before pressure signs, such as a bolt locked up tight enough to require a hammer to get it open and extract the case. Obviously above maximum pressure for Hornady cases with this bullet and powder, the last round fired at this level produced 2,890 fps, as well as finishing up a 5-shot 0.486-inch 100-yard group. Accurate, but too hot for this combination of components.
The next move was to work up a VihtaVuori N570 load with Berger’s 208-gr LRT. A starting load of 83.0 grains produced 2,755 fps, and a 0.578-inch group. Subsequent groups with increasing charges stayed under ¾ MOA.
Other Contenders
This Ruger Precision Rifle in .300 PRC stays under 1 MOA with loads that it doesn’t like, and hovers around ½ MOA with loads it likes. I’m looking forward to some thousand-yard matches at the local gun club, and this rifle is a prime candidate for the job.
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