March 11, 2022
By Joseph von Benedikt
To the delight of extra-long-range shooters everywhere, Lapua is now making cases for the .300 PRC, which has caught fire despite being relatively new. The cartridge features ultra-modern case design that maximizes efficiency, accuracy and consistency, and it’s engineered to be perfectly compatible with long, low-drag projectiles.
As competition shooters and savvy precision hunters know, Lapua creates the most consistent, best-quality cartridge cases available. And especially for those who shoot at really long distances, extreme consistency isn’t just a virtue; it’s a necessity.
Let’s take a look at what makes Lapua brass so good, and then run some tests and crunch some numbers to evaluate whether this .300 PRC brass measures up to its reputation.
Knowing it’s destined to be reloaded over and over again, Lapua makes its brass resilient. The company says case heads are drawn “exceptionally hard” for reloadability and a long life cycle. What it means is that its procedures equate to primer pockets that remain tight over a lot of high-pressure reloadings and retain their case-head dimensions.
What do I mean by “high pressure”? Certain demographics of shooters, such as Palma competitors shooting 1,000-yard matches with the .308 Win., push pressure limits to maximum. Tricks such as utilizing tough Lapua brass with resilient case heads and tight primer pockets enable them to do so safely and to get many consecutive reloads out of each cartridge case. This resilient toughness also helps brass spring back to shape properly after zesty handloads are fired, enabling easy extraction.
The flip side of resilient toughness only goes so far before it becomes a liability. How far? About two-thirds up the case, and no farther. Case shoulders and especially case necks must be flexible and malleable in order to grip bullets properly, expand immediately and adequately to properly seal off propellant gases when the cartridge ignites and to stand up to many resizing cycles.
Therefore, case necks and shoulders must be properly annealed, and Lapua is one of the few cartridge companies that intentionally leaves the annealing discoloration around the case necks so you know it’s been annealed.
Knowing each case will likely used by some of the most discriminating shooters in the world, Lapua maintains a level of consistency that’s made the company legendary. We’re talking neck thickness, wall thickness, primer pocket and flash hole concentricity, case head squareness, and much more than most of us will never even be aware of.
It’s quite a challenge, considering brass cartridge cases are produced in the millions, by machines that apply literally tons of impact pressure and force brass metal to flow like fluid.
My test rifle for this evaluation is a Proof Research Glacier Ti rifle that is incredibly accurate. Factory loads tend to average less than one m.o.a., and most handloads edge below three-quarter m.o.a. My best load averages a trace less than one-half m.o.a. with hand-sorted, neck-turned Hornady brass.
In order to evaluate how consistent Lapua’s new .300 PRC brass is, I weighed each of the 100 pieces on a digital RCBS scale, and crunched averages and percentages. Extreme spread for the weights was just 2.5 grains.
These cases weigh an average of 254.6 grains, more than 100 grains heavier than the average 6.5 Creedmoor case. In terms of percentage, 2.5 grains is about like a 1.5-grain variation in a batch of 100 6.5 Creedmoor cases. To put that in perspective, when weight-sorting 6.5 Creedmoor cases from most of the popular, high-production ammo companies, I typically find up to five grains of variation in extreme spreads, even within the same lot.
Those 2.5 grains of variation in that batch of .300 PRC Lapua cases represents exactly one percent of the total case weight. In contrast, five grains of variation in a batch of typical production-grade 6.5 Creedmoor cases represents more than a three percent extreme spread.
Better yet, exactly 90 percent of the Lapua cases were within a 1.6-grain spread. For a batch of cases that’s not presorted for weight, this is incredibly close.
And according to spokesman Geoff Esterline, that’s exactly the point. “Lapua’s state-of-the art manufacturing process holds such exacting tolerances, that there’s no need for prepping, sorting or weighing your cases for consistency,” he said.
Based on the results I found by weighing the cases, I decided to test the .300 PRC cases without any sorting or prepping. I did try to measure case wall thickness but didn’t really have the tools to do it with the consistency I’d hoped. However, my subjective impression is that case mouth thickness averages about 0.015 inch, with less than 0.001 of variation around the perimeter of each case mouth.
To perform a shooting test, I primed a batch of the Lapua cases with Federal 215 Gold Medal Match primers, charged them with 79 grains of H1000 propellant, and topped them off with 200-grain Barnes LRX bullets seated 0.050 inch off the rifling leade. This is the load that averages around one-half m.o.a. in my hand-sorted, neck-turned Hornady cases.
With my deadline looming, I had to do my testing on a hot afternoon—with the heat of the day and that from the suppressor on my rifle creating a lot of mirage—firing a series of three consecutive three-shot groups and getting a 0.62-inch average at 100 yards. Darned acceptable, I thought. On a still, cool morning, almost certainly the ammo would shoot under a half m.o.a. out of this rifle.
Real-world price for the new Lapua .300 PRC brass is around $140 per 100 pieces, or $1.40 per case. While that’s pricey, the .300 PRC is not a volume-shooting kinda cartridge. It’s made to place big, extreme-BC bullets precisely on target from truly long distances. A box of 100 cases will last most shooters a long time and will provide best-possible performance.