July 18, 2018
Starline has been making handgun cartridge brass for nearly 45 years. The company began making rifle cases just a few years ago, and it recently added 6.5 Creedmoor cases to the product line. Starline is the first company to offer 6.5 Creedmoor brass with either large or small primer pockets. I assembled and fired a few test loads to determine any significant difference in ballistic performance.
I started with 50 pieces of brass and two brands of Large and Small Rifle primers (CCI 200 and CCI 400 and WLR and WSR). I chose a favorite handload recipe that had proven accurate in several rifles and assembled 10 rounds each with the four primers. I used a Browning X-Bolt Target rifle topped with a Meopta RX-1 4-14X 44mm optic because it's a proven platform. However, this project expanded as the reloading and shooting sessions continued.
Before loading the first batch of test loads, I measured several cases to see if they required trimming. Each case was within a couple thousandths of the recommended trim-to-length (1.910 inches). I initially neck-sized them with a Redding bushing die (0.290-inch diameter). During each subsequent reloading session, I neck-resized and then trimmed and deburred using an RCBS powered case-preparation tool. The cases stretched very little with each reloading and firing cycle, and they were eventually loaded four times.
Altogether, I tested 16 batches of test loads and discerned a definite "better" performance bias with most of the Small Rifle primers. With a couple of exceptions, there was very little difference in average velocities, but the small primers almost always delivered reduced standard deviations and improved accuracy. I consulted Dave Emary, Hornady's chief ballistician and originator of the 6.5 Creedmoor, to share the good news.
He promptly poured cold water on my results.
According to Emary, "Typical 6.5 Creedmoor powder charges are simply too large to reliably ignite with Small Rifle primers under all conditions. They're just fine for .223 and similar capacity rounds; however, we're talking about nearly twice as much propellant. A Large Rifle primer is definitely needed to assure reliable and consistent ignition. If the throat is eroded and a round hang-fires, the bullet will plug the bore, and the reigniting propellant will likely fully burn before the bullet can began moving again. Skyrocketing pressures may damage the rifle and possibly injure the shooter."
I told him I appreciated his insight and that I'd get a second opinion.
Ron Reiber, Hodgdon Powder product manager, added even more cold water.
"Many propellants are sensitive to temperature variations," Reiber said. "If the ammo gets too cold, it's harder to ignite. Small primers contain less energetic material, so the risk of experiencing a dud round or hang-fire increases in cold conditions. And the 6.5 Creedmoor can achieve excellent ballistic performance loaded with a double-base propellant containing nitroglycerine. That type of propellant is more difficult to ignite than single-base, nitrocellulose powder, which only exacerbates the critical ignition process."
I then spoke with Joel Sandstrom, Federal's primer guru, and heard the same story. Sandstrom agreed that I could surely achieve excellent performance under just the right conditions, but the potential reward didn't warrant the real risk.
As the chart shows, my test load was 41.2 grains of Hodgdon H4350, which is a reformulated Extreme, single-base propellant that's much less sensitive to temperature variations. Coincidentally, I had already assembled a box of 6.5 Creedmoor handloads in once-fired PRIME brass (with Large Rifle primer pockets) with laddered charges of W760. I fired four, five-shot groups that averaged less than half-MOA in the X-Bolt and decided to repeat the test using Starline brass with small primer pockets. Velocity and accuracy data were less than stellar compared to the earlier results.
I informed my industry friends that I'd report my test results while cautioning handloaders to only reload 6.5 Creedmoor brass with Small Rifle primer pockets with single-base propellants and that they should fire these handloads only when they need a rag to mop the sweat out of their eyes between each shot!
Other New Brass from Starline
Starline recently added .338 Federal and .358 Winchester cartridge cases to complete its lineup of products based on the .308 Winchester as the parent case. Federal offers loaded .338 Fed. ammo but not component cases, and until Hornady recently started making .358 Win. ammo and brass, Winchester was the only source for it, and that was sporadic. Because both cases can be easily formed by simply necking up .308 Win. cases, I've never lacked cases to reload, but it's much more convenient and safer if your handloads have the correct headstamp to preclude inadvertent mix-ups.
I have several rifles chambered for the two cartridges, so I had to try the new Starline brass.
After a nice morning at the range, one of my favorite .358 Win. handloads comprising 48 grains of VihtaVuori N530, the Barnes 200-grain TSX bullet, and the CCI BR-2 match primer performed well. Three, five-shot groups averaged 1.27 inches, and average velocity pushed 2,600 fps with a standard deviation of only 15.
However, it's back to the drawing board with my .338 Federal load — no fault of the new brass, of course. It did what it was supposed to do.