July 21, 2020
While working my way through college at a local gun shop, I advised a customer frustrated with his inaccurate handloads to try match-grade primers. He bought a 100 pack of Federal Gold Medal caps, and the next week he came back brimming with enthusiasm: “Changing primers turned my rifle from a two-inch gun to a three-quarter-inch gun,” he said.
I’ve always been the type to walk the extra mile for anything that might have an effect on performance, and I’ve always purchased match-grade primers. They’re only a few bucks more per 1,000, and the peace of mind I get by knowing I’m leaving no stone unturned in my search for precision makes the cost worth it.
But do match-grade primers really make a difference? To find out, I recently performed a comparison test with two different rifles.
The first was my old go-to Winchester Model 70 in .30-06. It was customized years ago by Hill Country Rifles and has a Lilja barrel. The second is my favorite PRS rifle, a GA Precision in 6mm Creedmoor with a Bartlein barrel.
For the .30-06, I loaded five different test batches of ammunition, all using Nosler cases charged with 55 grains of Reloder 16 and topped with 175-grain Barnes LRX bullets. The only difference was the Large Rifle primers, of which there were five different types: Federal 210 standard, Federal 210 Gold Medal, CCI No. 200 standard, CCI BR-2 benchrest-grade and Winchester WLR standard.
For the 6mm Creedmoor, I also loaded five batches. Each used new Peterson brass with Small Rifle primer pockets and charged with 40 grains of Reloder 16. I used Hornady 110-grain A-Tip bullets.
Like the .30-06 test loads, I used both standard and Gold Medal grade Federal primers, and standard and benchrest grade CCI primers. For the fifth test batch, I used Remington No. 6½ Small Rifle standard primers.
Each test batch consisted of 10 rounds, which I fired in two consecutive five-shot groups, clocking the full 10-round string using a LabRadar. Conditions at the range were questionable, with wind gusting to 12 mph and temperatures hovering at a finger-numbing 25 degrees. At least the barrels cooled quickly.
Results were a little unanticipated, although one difference emerged almost immediately. I started with the .30-06 because it needed to cool completely between five-shot groups. The Creedmoor’s heavy match barrel doesn’t and historically has grouped a bit tighter during the second five-shot group in a 10-round string.
Firing the .30-06 handloads with Winchester’s Large Rifle primers, I was disconcerted to find accuracy relatively poor, in excess of 1.5 m.o.a. Also, one of the 10 primers failed to fire, even though I hit it with three consecutive attempts.
With Federal’s standard-grade 210 primers, the rifle was immediately happier, grouping much more consistently. But to my surprise, the .30-06 displayed little difference in accuracy between the standard and Gold Medal grade primers.
In fact, in both cases the match-grade primers produced a slightly larger group-size average. However, the differences are within the potential variability of human and environmental influence.
I did observe that Federal’s primers—both grades—produced significantly smaller velocity extreme spread and standard deviation. This proved true with the 6mm Creedmoor as well. You can see the complete data on the accompanying chart.
Adding up the velocity data, group sizes and observed anomalies with the .30-06, I had to conclude that aside from avoiding primers the rifle doesn’t like—in this case the Winchester Large Rifle—the rifle drew no advantage from using match-grade primers. From here on out, I’m going to be loading my .30-06 ammo with Federal standard 210 primers.
My tests with the 6mm Creedmoor told a different story. The Federal 205 Gold Medal primers produced a gratifyingly tight 13 fps extreme spread and just four fps standard deviation—small enough deviance to satisfy even the most particular long-range precision shooter.
Accuracy may have benefited too, but all five primer types produced accuracy averages within 0.15 inch of each other. That’s within my margin of error, particularly on the blustery day on which I conducted the comparison test, and is too minimal for me to draw any meaningful conclusions from.
Interestingly, the Remington primers produced two very nice groups and would actually have posted the smallest overall average, 0.54 inch, had it not been for one errant shot a half-inch out. It opened the average to a still-respectable 0.73 inch. Similarly, with CCI BR-4 Benchrest I had four shots in 0.41 inch but had a flier that pushed the average to 0.56 inch.
I had to wonder if the modest flier was my fault, or if it was caused by an inconsistency in the standard-grade primer. Truthfully, it could have been any number of things ranging from shooter error, handload inconsistencies or the gusting wind.
I was concerned to note that three of the 10 Remington primers were perforated by the firing pin. None of the other brands were. There was no powder residue around the perforated primers, and none of the primers in any of the test loads was flattened, so I don’t believe the perforation was a result of excessive pressure.
Rather, I’m inclined to believe the Remington primer cups are thin, and the small-diameter firing pin in the precision action simply punched through it. At any rate, promising accuracy notwithstanding, I’ll not be using Remington primers in my 6mm Creedmoor cases with Small Rifle primer pockets.
On the subject of pressure, I’ve always heard that CCI and Winchester primers have hard cups and are best for use with heavy loads. All the fired primers in the .30-06 test loads show flattening—within healthy limits— and while it’s a small sample size based on just one propellant type, one bullet type, in one caliber/case combination, I gleaned some interesting observations.
For one, the CCI Benchrest primers were the flattest of the lot, suggesting that they are no harder than the others and are perhaps softer. Most consistently shaped were the Federal primers, both match-grade and standard. Of all the primers tested, Federal’s stood out—primarily for the consistency of the velocities the cartridges primed with them produced.
Whether it’s worth it to pay the extra dinero for the Gold Medal version is up to you. I don’t think I’ll bother for working-rifle hunting ammunition.
However, my match rifle benefitted enough in velocity consistency to convince me: I’m stacking Federal Gold Medal fuses in my match ammo from now on.