With the announcement of the new 7mm PRC cartridge, we’re comparing it to 6.5 PRC and 300 PRC to see how it stacks up!
Disclaimer
Ultimate Reloader LLC / Making with Metal Disclaimer: (by reading this article and/or watching video content you accept these terms). The content on this website (including videos, articles, ammunition reloading data, technical articles, gunsmithing and other information) is for demonstration purposes only. Do not attempt any of the processes or procedures shown or described on this website. All gunsmithing procedures should be carried out by a qualified and licensed gunsmith at their own risk. Do not attempt to repair or modify any firearms based on information on this website. Ultimate Reloader, LLC and Making With Metal can not be held liable for property or personal damage due to viewers/readers of this website performing activities, procedures, techniques, or practices described in whole or part on this website. By accepting these terms, you agree that you alone are solely responsible for your own safety and property as it pertains to activities, procedures, techniques, or practices described in whole or part on this website.
7mm PRC
Here at Ultimate Reloader, we’re doing a series on the newly-released 7mm PRC to answer all of your questions. Check out our overview video.
This cartridge was announced 10/26/2022 at the NASGW show. It has a 0.284”/7mm projectile and a 2.280” case length, 0.340” shorter than 300 Win Mag. The cartridge’s overall length is the same as a 300 Win Mag. This makes caliber conversion from 300 Win Mag rifles very simple — just replace the barrel!
On June 28, 2022 SAAMI officially released the specifications for the 7mm PRC which you can download HERE.
With a limit of 65,000 PSI, and compatibility with 300 Win Mag and similar rifle platforms (including magazines), the 7mm PRC has great power and flexibility. If you have a long action magnum rifle (with 0.532″ bolt face), upgrading to 7mm PRC is likely just a barrel change!
Comparison
As you might expect, case length proportionally increases as you move through the PRC lineup.
The cartridge overall length is worth some special attention. The 6.5 PRC max COL is 2.955.” This pushes the short action platform to the limit. You’ll see notched feed ramps and have to pay special attention to which specific magazine you use for optimal feeding. Personally, I’ve never had issues with any of the rifles I’ve shown on the channel, the Bergara B-24 Wilderness HMR or my custom carbon fiber build.
The 7 PRC and 300 Win Mag have the same COL. This means that at 3.340” max overall length, the 7 PRC will fit comfortably into any long action. 300 PRC, at 3.700” max COL, pushes the long action platform to its limits, just like the 6.5 PRC does for the short action platform.
Case heads and shoulder angle are the same for all cartridges. This is nice as I can use the same Short Action Customs comparator inserts for all cartridges.
The 6.5 PRC takes a large rifle primer, while the 7mm PRC and 300 PRC use magnum large rifle primers. There may be some primer interchangeability with the 6.5 PRC, but be sure to consult manufacturer’s load data.
I spoke with Hornady and they said a 1:8.5 twist would also work with the 7mm PRC, but I prefer to stick with the SAAMI specs. Finding a 1:8 twist 7mm barrel blank can be a little difficult, so at least it’s an option. I personally worked with Bartlein Barrels and they were instrumental to me getting the build done on time.
I’ve built 300 PRC rifles with both a 1:8.5 twist barrel and a 1:9.5 twist barrel.
Baseline Ballistics
Going off of SAAMI spec bullet weights and velocities, we are taking match bullets and extrapolating hunting results. Actual results will vary.
- 6.5 PRC: 147 grain @ 2900 fps
- 7mm PRC: 180 grain @ 3,000 fps
- 300 PRC: 225 grain @ 2,800 fps
Here is an example Hornady 4DOF calculation for the SAAMI spec bullet weight and twist rate.
First, we compared trajectory. This data is based on a 100 yard zero, and shows come ups in inches. The 7mm PRC is the clear winner here, with a 228.812 drop from 100 to 1,000 yard drop. The 6.5 PRC and 300 PRC both had an approximately 30-40 more inches of drop.
When considering velocity, we looked at known data points. 2,000 fps is typically required for optimal expansion of copper hunting bullets. Hornady says 1,600 fps results in acceptable expansion with their ELD-X bullets. This chart shows all velocities 2,000 fps and over and green and anything between 1,600 fps and 2,000 fps in yellow. All three cartridges offer reliable expansion with ELD-X bullets out to 1,000 yards. If you are looking for 2,000 fps + velocity, the 7mm PRC holds this velocity out to 900 yards. Both the 6.5 PRC and 300 PRC last reach 2,000 fps at 700 yards.
Energy is another consideration. I’m using an arbitrary number, 1,500 ft-lbs, as the energy needed to drop an elk. Keep in mind that your personal threshold may be above or below that. 6.5 PRC lags behind the crowd in energy, falling below 1,500 ft-lbs at 600 yards. Most hunters’ shots will be within 500 yards anyways, so it is still a viable elk cartridge. The 7mm PRC and 300 PRC have similar performances when it comes to energy – the 7mm PRC just barely falls short of 1,500 ft-lbs at a 1,000 yards while the 300 PRC is just above.
Please note this is all hypothetical. A 1,000 yard shot on an elk is extremely far. I wouldn’t recommend anyone do that, but the ballistics data shows it is possible with the 7mm PRC and 300 PRC.
Wind drift affects both target shooters and hunters. The 7mm PRC bucks the wind the best, with a 44.7538 inch drift at 1,000 yards. The 6.5 PRC has the largest wind drift.
It’s especially interesting to compare these three PRC cartridges. All are good for hunting, but I believe the 7mm PRC is especially suited for both hunting and target shooting. Recoil is mild and velocity and wind drift performance are impressive.
I haven’t been able to conduct my full accuracy tests and load development, but my first three shots out of my custom BAT action 7mm PRC build with Hornady 180 grain Accuracy Match fell into a 0.359” group. I have confirmed the published velocities and have already found higher velocities with my 28” barrel. The Bergara build focused on more compact and suppressor-friendly handling dynamics. It is about 150 fps behind the 28” barrel in velocity.
Initially, I suspected Hornady would neck up the 6.5 PRC, but instead they created a competitor to the 7mm Rem Mag and 300 Win Mag that beats them both in factory comparisons.
Conclusion
The 6.5 PRC is the only PRC that fits a short-action platform. The 7mm PRC is what I call the “all-rounder.” It’s easy and accurate to shoot with great ballistics for shooting and hunting. I’ve also found it easy to load for. It also drops right into a standard internal or detachable magazine and feeds into the long action with no issues. The 300 PRC is the heavy-hitter of the group.
In terms of pure ballistics, I believe that the 7mm PRC is just as good as the 300 PRC. All three of these cartridges will work and get the job done, unless you are planning on taking elk past 500 yards.
Don’t miss out on Ultimate Reloader updates, make sure you’re subscribed!Thanks,
Gavin Gear
