Charge weights: What's your limit on accuracy?

[dadajack]

How does 1/10th a grain difference in a case that holds upwards of 42 grains powder translate to more accurate loads? I shoot long range, not competitively obviously, but with varying success. I attribute that to my skills and impatience mostly, but perhaps the tools I load with or the platforms I use are not capable of greater accuracy as well.

So, I think we all give credence (see what I did there? ) to the OCW method, which gives us a range of charges that provide the least amount of vertical deviation at range. For some rifles, like my Savage 12, that node is not very large. Hence, I measure to 1/10th grain accuracy, which is all my equipment is capable of. Unless you consider the analog readout of a beam scale to be infinite as I do, then I can simply produce the same measurement to within 0.01 based on my professional eyeballing abilities honed during years of upscale remodeling and woodworking practices.

Theoretically though, we should be able to drop powder in a given node, depending on the particual rifle, within +/-0.3 grains and still get MOA or better performance, right? I also understand that producing the least amount of variation between individual rounds produces the highest POTENTIAL, not guarantee, for greatest accuracy. So many variables come in to play when we are at the range, I guess it only makes sense to reduce them while we are in the controlled environments of our reloading rooms... or garages... or wherever you load.

[eas1949]

A 20 ft/sec change in velocity  equates to a 5 in vertical change at 1000 yds.  (  Berger 140 hybrid 2780-2800 ft/sec JBM program)

The more perfect the powder charge the better velocity spread ,  all other things being equal.

Eric

[dadajack]

But, haven't we all seen loads with higher SD perform betten than others with lower SD? Or is this a function of us all being human and throwing shots with better loads than others? So much of this hobby seems to be black magic, or something.

Consider this as well, if you monitor the chamber pressure for 10 cartridges all loaded EXACTLY the same, you WILL get variations of hundreds of PSI, if not more. How does that factor in? Chamber pressure is not equal to velocity. I guess the best thing for me to do is stop thinking about it and just enjoy it when I have a good day at the range, or any day for that matter.

[Aussie65]

Shooting 140 VLDs I have used 2 nodes
1 between 40.8 & 41gr the other between 42.5 & 42.7 gr of AR2209(H4350)
Rounds I have loaded on any of these 6 charge weights have always been excellent accuracy wise in 3 guns now. .1-.2 @ 100yds & around .3 -4 @ 300
Now I have the opportunity to shoot to 1000m I will see what more needs to be done maintain the accuracy
I have always been very precise with trimmed case length & more recently playing with neck tension. After all this is the part that grips the projectile.
I think my neck turned & inside reamed Lapua brass has been an improvement also. Very concentric & smooth finish internally on the necks.
My 2c on this is if you try something new & it improves YOUR result you are on the right track if not, scratch it & move on. It's not a failure.
Don't forget to have fun & don't take it too seriously. An over exaggerated fixation on accuracy can take the fun out of it.

[The Marshall]

I agree that weighing to 0.1 grains is a way to create better loads. I will not trust my quite old and used Lyman 55 powder dispenser to give me charges within 0.1 gn.

If you weight your cases and your bullets, you'll be even closer to making identical loads. The situation will never be totally solved since eight to twelve cases from a box will weigh the same, the others being heavier or lighter. I think the best you can do it load the same amount of powder and use as many bullets of the same weight (again to 0.1 grains) in cases that are the same weight or as close as you can get it. For hunting accuracy, this is all that is needed. The deer or pronghorn isn't going to know you or I hit slightly higher or lower than our intended impact point.

[Danbonzo]

I agree that weighing to 0.1 grains is a way to create better loads. I will not trust my quite old and used Lyman 55 powder dispenser to give me charges within 0.1 gn.

If you weight your cases and your bullets, you'll be even closer to making identical loads. The situation will never be totally solved since eight to twelve cases from a box will weigh the same, the others being heavier or lighter. I think the best you can do it load the same amount of powder and use as many bullets of the same weight (again to 0.1 grains) in cases that are the same weight or as close as you can get it. For hunting accuracy, this is all that is needed. The deer or pronghorn isn't going to know you or I hit slightly higher or lower than our intended impact point.

But the paper or steel will?

[The Marshall]

I agree that weighing to 0.1 grains is a way to create better loads. I will not trust my quite old and used Lyman 55 powder dispenser to give me charges within 0.1 gn.

If you weight your cases and your bullets, you'll be even closer to making identical loads. The situation will never be totally solved since eight to twelve cases from a box will weigh the same, the others being heavier or lighter. I think the best you can do it load the same amount of powder and use as many bullets of the same weight (again to 0.1 grains) in cases that are the same weight or as close as you can get it. For hunting accuracy, this is all that is needed. The deer or pronghorn isn't going to know you or I hit slightly higher or lower than our intended impact point.

But the paper or steel will?

Good point. 

[Danbonzo]

I agree that weighing to 0.1 grains is a way to create better loads. I will not trust my quite old and used Lyman 55 powder dispenser to give me charges within 0.1 gn.

If you weight your cases and your bullets, you'll be even closer to making identical loads. The situation will never be totally solved since eight to twelve cases from a box will weigh the same, the others being heavier or lighter. I think the best you can do it load the same amount of powder and use as many bullets of the same weight (again to 0.1 grains) in cases that are the same weight or as close as you can get it. For hunting accuracy, this is all that is needed. The deer or pronghorn isn't going to know you or I hit slightly higher or lower than our intended impact point.

But the paper or steel will?

Good point.

LMAO just having fun bro. You're right they won't know what hit em!