How important is one kernel of powder?

[Fairchaser]

Looking at the high end powder throwers and scales compared with the chargemasters and the like and wondering how important a kernel of powder is in precision. For my load, one kernel divided by FPS is about 1 to 1. At 600 yds that’s equal to about .1 inches. One tenth of a grain is equal to .6 inch. Most of the cheaper powder measures are within .1 grain or 6 kernels of varget. You can get even more precise if you trickel up. I realize the relationship between kernels of powder and FPS is not linear but .1 or .2 of an inch seems insignificant at 600 yds. That much could probably be tuned out. What say ye?

 

[BCBRAD]

I use an A&D 120i for weighing powder, brass, bullets etc. it resolves to 0.02 gns. Find that is easy to use plus has other benefits than just weighing powder. Also, with accurate weights and measures any soft ware used will enable said soft ware to be more accurate as errors are not compounded or at least attenuated.

 

[RedfootRanch]

I use an FX120 and don't worry about a single kernel based upon how that single kernel corresponds with .02 grain output change.

 

[Bc'z]

The anal side of my OCD says 1 kernel is everything.

 

[JMayo]

I know what the kernels weigh so getting as close as possible without being under is possible.

If one doesn't matter where is the point it does ?

Bench rest, lab scale, manual throw.

 

[MGYSGT]

Some of those benchrest guys reload at the range and don't even weigh the charges.

 

[H2OBUG]

I think it all depends on where you are in the velocity curve. If you are in the up and to the right portion it may matter a lot. If you are in the flat section should make zero difference. That is why you load in the flat section.

 

[Chubbs]

I think it matters more in your head. Especially when you can't account for that flyer. As its all about being consistent and minimising the variables. It probably won't make any noticeable difference but you will always wonder. So why not give yourself one less thing to wonder about.

 

[1K6BRA]

If you don’t worry about plus or minus one kernel of powder your fellow competitor sitting next to you probably does.

 

[DiffEQ]

@Fairchaser , you answered your own question.
Perhaps you've never used a Chargemaster or other affordable production autodispenser? I've owned a chargemaster and a Hornady auto-charge. In a perfect world, they are spot on, which might be 10% of the time. Rest of the time, they're often .2gr or more over. The Hornady was particularly irksome because it would toss anywhere between .2 or .3 over, beep it's "over spec" alarm and then the scale would display the target weight, not what was actually in the pan. The chargemaster pizzed me off with it's feed issues - and yeah, I did the straw hack and other stuff. Found that the guts of a Bic spring loaded ball point pen worked the best for consistent, accurate delivery. BUT, it made it friggin' s-l-o-w.
Now use a Belding and Mull powder drop, put into a US Solid scale and then use an RCBS hand trickler. Takes 10-15 seconds per charge when I'm moving slowly, and I have easy control over every kernel.

 

[rjtfroggy]

If you can shoot the difference in 1 kernel of powder you are much much better than me or many others here.

 

[Ranger188]

It might not matter that much. But it's a variable I can control.
The less variables the better the load and groups.

 

[garandman]

Most of the cheaper powder measures are within .1 grain or 6 kernels of varget.

0.1 gr of Varget for me was 2-3 kernels.... i.e. 2-3 kernels would change digital read out on the scale from 41.4 to 41.5 gr.

 

[MarkG]

Modern Advancements in Long Range Shooting Volume 2 by Brian Litz addresses this question in Chapter 4. Powder measure, Chargemaster and Satorius trickled to the kernel are compared by measuring velocity SD. Good scientific methodology is used to generate lots of data. The answer depends on how low of an SD you need to achieve the desired accuracy.

 

[Fairchaser]

I use a chargemaster and a dandy trickler and it’s pretty easy to load low .1 and trickle up one kernel at a time until it changes. Sometimes it takes 2,3,4 or 5 kernels but mostly 6 which is the weight of .1 grains. This tells me that the chargemaster will overthrow a few kernels but I feel like I’m getting within 1 kernel by trickling up. Now the scale drifting is another matter. Sometimes the scale will show 177.1 without the pan and sometimes 177.0. I will re calibrate and rezero but it makes one wonder. So far, I’m not noticing high or low flyers and a very tight water line. But, I’m always looking for more precision and wonder where I should spend the next $1500.

 

[Fairchaser]

0.1 gr of Varget for me was 2-3 kernels.... i.e. 2-3 kernels would change digital read out on the scale from 41.4 to 41.5 gr.

That could be the variance in my scale which is the chargemaster scale. It takes 6 kernels to change .1. It could be from the edge of one to the max on the other of .1.

 

[garandman]

That could be the variance in my scale which is the chargemaster scale. It takes 6 kernels to change .1. It could be from the edge of one to the max on the other of .1.

Mines a Frankford Arsenal, which I find to be adequately accurate. Not siginifcantly better than the RCBS, to my knowledge.

I dunno but it kinda sounds like your scale is "locking in"on a charge weight in 0.1 gr increments... until it gets "pushed" to the 0.1 gr higher weight.

One trick I use is when the scale is flipping back and forth 0.1 gr, at the end of the trickle, I'll tap the pan edge and then see where it settles. Might even do this twice. Often adding a single kernel of powder will cause the scale to "settle" and read a consisant charge weight.

YMMV.

 

[6MMsteve]

precisiion cut kernals then counted is the answer, I now have the secret

 

[coldboreshot]

There was a point where certain people were cutting kernels in half for their match loads.

 

[dcali]

The relationship between powder and velocity *is* linear. Or more accurately, it's so close it may as well be. Don't fall into the trap of attributing vertical point of impact change solely to velocity. In reality, a very large part of vertical is due to tune that compensates for variable velocity. As long as the velocity variation can be tuned out, you're good. And in my experience, at 600, you can tune out quite a bit. A 2-3 tenths variation of powder in a 6BR, for example, will give you the same vertical POI. 1 kernel isn't going to do squat.

Now, if you've found yoruself right at the edge of a ladder step... well, add or remove a tenth or more. Don't try to finesse it with a kernel at a time or you'll have a bad time. It's better to give up a few fps in velocity than live on the edge of a node.

In smaller cases and longer ranges, things get harder. But one kernel generally isn't meaningful if everything else is right.