Powder Kernel Uniforming for Ultimate Long-Range Accuracy
Successful long-range shooters know that careful weighing of powder charges helps them achieve superior long-range accuracy. By maintaining powder charges within very narrow weight tolerances, hand-loaders can produce ammo with more consistent muzzle velocities from shot to shot. Low Extreme Spread (ES) and Standard Deviation (SD) numbers translate directly to reduced vertical dispersion at very long ranges (although velocity is not the only contributing factor to vertical spread). In pursuit of load weight uniformity, many of our top long-range aces have invested in the latest, high-tech magnetic force restoration (MFR) digital scales (such as the Sartorius GD503). These laboratory-grade MFR scales are extremely stable (with minimal drift) and they can reliably measure to .005 grain, that is five thousandths of a grain. That is less than the weight of one kernel of typical extruded powder. For example, with Varget, there are three to four kernels in one-tenth of one grain of Varget. That means each kernel weighs .025 to .035 grains.
With the capability of modern modern MFR scales to measure less than one-hundreth of a grain, we have a new frontier in precision reloading. You’ll note, in the preceding paragraph, we said that one-tenth of one grain of Varget is three or four kernels. Well, “which is it?” you might ask. The answer is that it might be three, or it might be four, depending on the size of the individual kernels. That’s a disturbing uncertainty that we simply had to accept… until now.
Powder Kernel Uniforming — A Breakthrough
We now have the tools and the methodology to resolve the inherent uncertainty in individual kernel weight. Using the new technique of powder kernel uniforming, first pioneered by German Salazar, we can now, for the first time, ensure that every kernel of powder that goes into a cartridge is virtually the same weight — the same, in fact, within 0.01 grain (one-hundredth of a grain) TOTAL spread.
For a reloader looking to achieve “perfect” load weight uniformity, powder kernel uniforming offers the ultimate control over powder weight. The method we devised to uniform individual kernels consists of kernel core-drilling. The propellant we chose for this kernel-uniforming test was a new prototype (not yet commercially available) EuroChemie RL “X” propellant. This was chosen because it offered relatively large, can-shaped kernels that could be drilled relatively easily.
Core-Drilling Kernels with Micro Drill-Bits
The center of each kernel was bored out with a micro-drill. But here’s the key. Before drilling, we first weighed each kernel. Then we selected a micro drill bit of appropriate diameter to achieve uniform weights. With the heavier kernels (in the 0.04 gr range) we used a larger micro-bit. With the lighter kernels (in the 0.02 range), we selected a smaller diameter micro-bit that removed less material from the center of the kernel. Obviously, many kernels were ruined while we perfected the drilling process. It required great patience and a very steady hand. But after a few dozen hours of drilling, we had a batch of uniformed kernels that were all within plus or minus .005 grains (.01 grain ES). Now we were ready to do some testing.
Proof That It Works
All this time-consuming work to drill holes in individual kernels would be pointless, of course, if it did not produce meaningful accuracy gains. The proof, as they say, is “on the target”. We were curious to see if our uniformed powder kernels would out-perform unmodified kernels, so we did some field testing. We prepared two batches of 6mmBR ammo in Lapua brass, with full case prep, and bullet base to ogive sorting (we wanted to eliminate as many variables as possible). Bullets were Lapua 105gr Scenar Ls, which proved to be some of the most consistent projectiles we’ve ever measured.
One set of rounds was loaded with a carefully-weighed charge of unmodified kernels. Case to case charge weight was held to .05 grain (half a tenth uniformity). Then we prepared a second batch of cartridges with uniformed kernels, using the exact same charge weight, also held to .05 grain (half a tenth) tolerances. We took these rounds to the range, and did a “round-robin” test at 800 yards, shooting one of each type in sequence (i.e. one uniformed on right, then one non-uniformed on left) until we had two 10-round groups. The test was done with a rail gun fitted with a 1:8″ twist, 28″ Krieger 0.236″ land barrel. The uniformed-kernel ammo was shot at the right diamond, while the non-uniformed rounds were shot at the left diamond. Conditions were good, so we simply “held center” on every shot. No attempt was made to correct for wind as our primary concern was vertical dispersion.
Ammo with Uniformed Kernels Shows Significantly Less Vertical Dispersion at Long Range
As you can see, the uniformed-kernel ammo out-performed the non-uniformed ammo. The difference is quite clear. The rounds with non-uniformed kernels (on the left) produced a 10-shot group with roughly 3.0 inches of vertical dispersion. On the right, our ammo with uniformed kernels produced a group with 9 of 10 shots showing roughly 1.75 inches of vertical dispersion (we did have one high flier among the uniformed-kernel rounds). Additionally, we had a lower 10-shot ES and SD with the uniformed-kernel ammo. We repeated this test two more times and the results were similar. The targets speak for themselves. If you are looking for ultimate long-range accuracy, powder kernel uniforming is a “new frontier” you may wish to explore. With all other factors held constant, we were able to reduce vertical dispersion by more than an inch at 800 yards by drill-uniforming our NitroChemie powder. That’s huge in the long-range game.
Yes, the kernel-uniforming process is incredibly time-consuming and tedious, and a set of micro-drills is not cheap. We also freely acknowledge that the process may be much less productive with narrow-kernel propellants that are hard to drill. (Also EuroChemie powders are preferred because the burn rate controlling compounds are impregnated throughout the entire kernel — not just the outside.) But the potential for significant accuracy gains is there. We proved that.
Is it worth the huge investment of time to drill your powder kernels? That’s a question each reader must ask himself. But if you know the competitor on the next bench over has uniformed his kernels, can you afford not to do the same? Sometimes the extra effort is worth it, just for the peace of mind you get knowing you’ve done everything possible to achieve “ultimate accuracy”.
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Tags: German Salazar, Kernel, Long-Range, Micro-Drill, Powder, Propellant, Vertical Dispersion
Now that’s a good one fellas!
just a touch to far !!!
This has got to be an April fools story
FUNNY, APRIL FOOLS!!!
Bloody marvelous way to usher in April Fools!
LMAO!!!! I’m gonna do a whole pound of powder this afternoon.
Maybe
haha! I look forward to 4/1 every year, just to see what the Daily Bulletin will hold.
While uniforming powder kernels is an excellent idea for those shooters with more time than talent, I would suggest an easier approach that might eliminate the vertical flyer in the example. By drilling the ID of the kernel to different diameters to uniform the weight, German also changes the surface area of the kernel, affecting the burn rate. Since extruded powder is extremely consistent in diameter (as determined by my measuring thousands of kernels), the primary cause of weight change in kernels is due to inconsistent lengths. Simply milling one end of heavy kernels eliminates the need for many different micro drills and minimizes the surface area changes on each kernel.
Had a hard time uniforming my ball powder for my 223 loads, they just didn’t look like the ones in the picture, so I stacked them 6 high and epoxied them together. Now I’m worried, will the epoxy change the burn rate of my load?
-bnw
Well played yet again ! This is the first page I open on April 1, great laughs and very creative.
We have come up with an alternate strategy. Powder grains are mounted, with a special fast drying laquer, on a plate that was previously ground flat, with both sides parallel, and then the plate,and mounted powder are surface ground , uniforming the length of the grains, at which point the plate is immersed in a solvent that dissolves the mounting lacquer, which is decanted off of the resulting slurry, in a three step process that ends with a final rinse with Grey Goose vodka, that is later used to mix a drink that is reputed to make those that consume it believe that the standard deviation of their ammunition has descended into the realm of negative numbers, and that the wind will only influence the flight of their bullets toward the center of the target.
This article should be listed as a must read Sticky on every forum page! That way, when we find ourselves trying to be more obsessive/compulsive than the guy who started the thread, we can sit back, take a deep breath read this again and laugh out loud like I did today!!! Great job!! I am crying and laughing!
Stay tuned for a report on the new Dillon progressive drill press, it really speeds up the operation.
At least it’s not time consuming.
Hey….somebody highjacked my idea. I started this ten years ago, and just finished drilling enough for a ten shot group. Guess what?…now 44.7 of 4350 is enough to fill up two cases…”scratches head”.
Nice article on this first day of April.
What are you guys smoking?
7000 grains to a pound, .025 to .035 averaged = .030. .030 x 33.3 rounded =1.
233,100.00 Kernals t the pound. If 44.2 grains is what your are loading, that would equal 1,471.86 kernals per load. Also suming you uniformed a kernal every 10 seconds. It would take you 245.31 minutes to uniform the powder for one shot. 4 plus hours per cartridge. Sounds like the cost of shooting will go up exponentially.
Great April fools gag Paul and others.
p.s. My varget doesent look like your processed grains even under 40 power magnification.
Nat Lambeth
Took a minute. Then I checked the date of the post. I love this every year. Keep it up guys! Now I just need to find a micro drill and more time than brains.
Hummm, an April fools joke….I should have known, because nobody mentioned the doubling of the burning rate or reducing the load. I didn’t mind the bolt passing through my cheek bone, but getting a bill for two cows and a John Deere didn’t make me happy….not to mention my barrel that passed through the chrono at 5620 fps.
I have actually obtained better results using laser interferometry. I have a narrow pulse laser that emits in the green portion of the visible spectrum. I focus this through the central pore of each kernel. Based upon the number of concentric rings emitted from the opposite end, I can group the kernels accordingly.
I just use a blender on high speed!
10 stories that could be April Fools pranks but aren’t (
http://www.bbc.co.uk/news/magazine-17580629)
I would have put this with the Zombies one, as one of the true stories listed was:
“Russian leader Vladimir Putin has given the go-ahead for guns that turn victims into “zombies” by targeting their central nervous system.
More details (Mail on Sunday)”
That was a good one! I kept waiting for them to explain how that process would’nt effect burn rate! And then when I read about the groups (and teh “flyer” I thought Man what a Joke—I was right!