Weighing powder to the kernel

[Ccrider]

Of course, charge weights relative to case capacity might have something to do with the width of the node. Either way it's not a kernel. Which was the point.

I agree it’s not a kernel.

This thread has drifted from the not very serious original post but there’s a super easy test for how much powder matters if you have a good beam or scale: Load 10 rounds with +\- 0.1gn variation, and load another 10 with +\-0.02gn and go shoot them.

I found the answer for me in my discipline of 1000yd benchrest. Some things don’t matter, like cleaning your primer pockets, and some things do. If it matters, you’ll see it when you test it. Be pragmatic and don’t surrender to dogma.

It would seem to me that one should get the answer when working up a load. The idea is to do charge increments that indicate the effect on the point of impact on the target. And then repeat to see if the change was anecdotal or is caused by the powder charge increase.

What I generally see is a gun comes in tune and will shoot ok either side of a .2 or .3 window. This holds until I get to the top of the powder capacity - the high node, where the gun goes in tune and shoots small, but add .2 grains and the load blows up.

With all that said, some barrels/cartridges are more forgiving than others. What I see in a Dasher or Bra is different than what I see in a 30br.

 

[davidjoe]

For my 6.5x47 and my 22BR, I can go to .04gns without seeing any detriments. +\-0.1 is too much though and I see inches of vertical show up at 1000yds that isn’t there otherwise. Not sure I would see it at 300 and in. Shows up at 500 and beyond though.

My 300 WM loads in the area of 70 grains and i do shoot heavies, 250 grain bullets. I think I’m at the verge of seeing larger groups at 1,000, although at 600, I believe I’m am still fine with .2 grains spread. I’ll typically try to put loaded rounds next to each other that do not vary by more than .1, but within my set of 25 rounds, I don’t like to have more than .2 variance.

An MTM magnum box of 100 is divided into four squares of 25 rounds. I find that amount to suffice for 20 record round matches. I simply start each quadrant with the leftmost bullet nearest the front and move right then back. So long as the 25 rounds shot in the same match are very close together, it is not as critical if I took a loading break and the next 25 are not exactly the same nominal amount. Daytime temperatures I find, which increase but are otherwise unpredictable, will affect pressure more than a small scale jump or dip from a 3 hour break between sets, in reloading.

I do think greater case volume forgives some excess tolerance but I think .3 would really be pushing things at 1,000 and .2 may also be, so I’m dumping the overages, but importantly, trying hard to keep consecutive shots either the same or within .1.

 

[Evan]

I agree it’s not a kernel.

It would seem to me that one should get the answer when working up a load. The idea is to do charge increments that indicate the effect on the point of impact on the target. And then repeat to see if the change was anecdotal or is caused by the powder charge increase.

What I generally see is a gun comes in tune and will shoot ok either side of a .2 or .3 window. This holds until I get to the top of the powder capacity - the high node, where the gun goes in tune and shoots small, but add .2 grains and the load blows up.

With all that said, some barrels/cartridges are more forgiving than others. What I see in a Dasher or Bra is different than what I see in a 30br.

I’d suggest that is a theory. Have you tested a tuned load with +\-0.1 and +\-0.02gn spread and verified?