DISCLAIMER: This is a guide. Everything listed within is for information purposes only. All loads should be worked up carefully. We have seen loads that require as much as two grains of charge weight adjustment from one powder lot to another. We have seen as much as five grains of powder adjustment required between different brands of brass. Failure to start low could result in damaged equipment or injury. USE AT YOUR OWN RISK.
7 MM PRC Cartridge Guide
Here we go again. Hornady announced the 7 PRC. In a market with many similar options, why do we need another? The short answer is that the others are poor designs by today’s standards. I imagine the design goals for the 7 PRC were much the same as the 6.5 and 300 PRC. Like the other PRCs, the parent case of the 7 PRC is the 375 Ruger. Hornady surprised everyone by splitting the difference between the other PRCs. The 2.28″ case length is perfect for a 7mm magnum cartridge. The number one selling point of the PRC cartridges is the modern throat design. The 7 PRC’s freebore of .233” makes it very flexible. It is not too long for the shorter bearing surface 180s and not too short for the larger bullets like the 195 Berger. At SAAMI length, the 7mm PRC will fit inside the 3.4” magazine boxes of last century’s design in SAAMI form. With the larger bullets, it will exceed the 3.4” magazine, but will not need a Wyatt’s box.
7MM Cartridge Options
There are numerous other options when considering a 7mm rifle. On the larger side, we have the 7mm Remington Magnum, the 7mm LRM, the 7mm RUM, and the 28 Nosler. You have the 7mm Winchester Short mag with identical case capacity. Then the 7 RSAUM is on the smaller side. So, what does the 7 PRC offer that the others do not? Let me rule out the 7 RUM and 28 Nosler right off the bat. They are too overbore for me. They wear throats out very quickly, are more prone to carbon rings, and are more difficult to keep in tune. They have short throats and need a custom reamer to make full use of the case’s abilities.
Let’s focus on the 7 RSAUM, 7 WSM, 7 Rem mag, and 7 LRM. Of the bunch, the 7 RSAUM is going to be the most accurate on average and will stay in tune with less work, yet it suffers from a few problems. At SAAMI length, longer bullets occupy too much case capacity. This is a major reason why it has disappeared from factory offerings. When built with a custom reamer and rifle, it is still a great option. The 7 WSM has the same capacity as the 7 PRC, but it suffers from the same shortcomings as the RSAUM. The 7mm Remington Magnum has anywhere from 1-3 grains more H2O capacity than the PRC. Once again, it suffers from a throat that is too short for modern bullets. It remains a great cartridge but has room for improvement. This is the main cartridge the PRC will have to outperform, as far as sales go, to stay around. The 7 LRM is a nearly perfect cartridge for the caliber and the bullets we currently have available. The only issue with it is it is not SAAMI-approved. This makes it a non-starter for production rifles. When compared to these options, the 7 PRC leaves little to be desired in a 7mm cartridge. The case capacity is perfect and the freebore is forgiving. These reasons are why the 7 PRC is going to be the best 7mm cartridge available in factory chamberings. If the success of the 6.5 and 300 PRC is any sign, this cartridge will get tons of aftermarket support. Hornady’s marketing will make this cartridge very popular. The anticipated aftermarket support will be what ensure this cartridge sticks around.
Why Choose The 7MM PRC?
Ok, so none of this tells you why you would build a custom rifle chambered in this cartridge. I have always loved the 7mm cartridges, with the 7 WSM being one of my favorites. Its capacity seems to be the sweet spot. The 7 PRC has the same capacity as the 7 WSM. It is slimmer and longer. This should make it easier to feed from a long-action magazine. I have found the short magnum cartridges don’t feed well from short actions. Because of this, I don’t see the point of short magnums in short actions. The 7 PRC will not quite compete with the 7 RSAUM in the raw accuracy department, but it is close. It will yield more velocity on average. This will translate to smaller horizontal dispersion in adverse conditions at long range. On average, it should also shoot flatter. It will run right with the 7 Rem Mag without needing a custom chamber. These are the reasons this cartridge is likely to be a success. Let’s get into the load information.
Bullets
We are choosing to focus on 175 and larger bullets for now. When time permits, I will work on some 168 Berger data. I don’t see the point of shooting smaller in a .284 when you could shoot the 156 Bergers from a .264. Any of the 168-180 grain bullets will be right at home in this case. My favorites are the Berger 180 VLD and Hybrids, as well as the 180 ELDM. Testing with the 190s and 195s will continue and this guide will be updated when more data is collected. Hornady kindly provided us with the load data provided below. I checked it with 180 Bergers and 180 ELDMs, except for the RL22 loads. This is because RL22 was too temperature sensitive in my previous testing.
******The loads in the above chart are all max loads. WORK UP!******
Powders
The 180s will do very well with the normal powders for this sized case. H4831SC and RL23 should offer good accuracy and low extreme spreads in velocity. They generally will be on the faster side in burn rate, which will yield lower max velocities. Retumbo, N565, and RL26 will perform well and will yield the fastest velocities. My barrel did not yield great accuracy with Retumbo or N565. If I were set on using these two powders, I would try some different primers. RL26 was accurate in my rifle but is not quite as stable as H1000. My favorite powder for the case is H1000. It provides great accuracy and extreme spreads. Velocity will fall right in between the other powders. I have settled on the low node with H1000 and 180 Hybrids at 2895 fps out of a 26” barrel. The case can go quite a bit faster, but the node was just too wide and stable to ignore. The larger bullets will still do great with these powders and will allow the use of slower powders like N570.
******While these may work in our rifles, they may be too hot in yours. WORK UP!******
Primers
Any of the large rifle primers should work in this case. In my experience, with this case capacity, the faster powders do best with Federal 210Ms and CCI BR2s. The slower powders do well with CCI 250s or Federal 215Ms. Don’t be afraid to experiment. Most of my testing was done with CCI 250s. Forum member 8nbait was having better luck with Federal 210Ms.
At the time of launch, the only case options will be Hornady and RCC. My testing was done with Hornady brass. Forum members 8nbait and Weatherbyfan were using RCC.
Comparing 6.5 vs 7 vs 30
Bullet mass and impact velocity should be heavily considered when choosing a cartridge. The correct choice will ensure ethical kills at your maximum range. The bullet mass is going to have a direct impact on the recoil. For some, this needs to be considered. I will never advocate shooting elk with calibers smaller than .308. However, 30-caliber magnums are not needed for deer and antelope-sized game. The 7mm caliber is a great choice for deer and smaller game. Too many people focus on energy as a killing power indicator. Based on countless instances of anecdotal evidence, this is just not the case. Bullet mass and impact velocity are better predictors of how fast an animal will go down. This mainly applies to frangible bullets, which we prefer over bonded bullets. Below is a comparison between a few different cartridges in each caliber. You will see they look very similar on paper. Just keep in mind bullet mass means more shrapnel to destroy the vitals of your target.
7MM PRC Conclusion
If you take a look at a reloading manual, you will not see much of a difference between the 7 PRC, the 7WSM, and the 7 Rem mag. What you are gaining is a better-designed factory chamber. The longer freebore will allow a reloader to make better use of modern bullets. The 7 PRC’s modern design will lead to a much better selection of factory ammunition. However, if the success of the other PRCs is an indicator, this cartridge will continue to grow. It will be a hit with those using factory ammunition as well as reloaders. The cartridge will be great for all hunters. Whether you choose a factory rifle or go the custom route, the 7 PRC is worthy of your consideration. The link below will take you to a thread on the forum with members’ input on loads that have worked for them.
Comment or ask Ryan questions here.
Watch the 7mm PRC Cartridge Guide Video here.
