Moorvogi
Firearm Advocate
- Dec 28, 2014
- 855
Please excuse my ignorance, but what is this OCW and Node you guys are referencing?
I was focusing solely on group size and charge weight.
Looks like a chance to learn something new here.
Did you shoot these "round robin" or shoot all of each charge weight into the same spot before moving on to the next charge weight? I've heard arguments in favor/against each method but have always stuck to the later method with my testing.
The other method I've found interesting (but have not tried) is the one where you load 10 rounds in increasing charge increments (e.g., 22.0 to 25.5) and look for a velocity flat spot that theoretically should be centered around a node.
I think you might want to increase powder charge for the 75gr. 24gr of varget and 75gr hornady seems to be the trick. Obvouisly work yoir way up in 1% increments
GREAT question. To each their own but, i shot each group before moving on to the next. The reason is, if the temp increases as you shoot. the middle group is always "warm but not hot".
When i did my 300 win mag (Savage 110BA Stealth).. i shot all 5, one after another (bolt action) took about 1 minute per shot. Then waited the rest of the cease fire (about 20-25 minutes) before doing the next group. EVERY group had the same rate of fire and benefit of the same barrel temp start to finish.
Looking at the 75gr (ignoring the pen marks and looking at the typed charge values...) it appears that 20.5 is my best OCW and scatter is 22.5.
The 55gr, i'm going to say is.. looking like 22.5gr though i can't identify/verify it against an obvious scatter node.
Any ideas/feedback from fellow OCW reloaders?
I wouldn't concern myself with .2 grain increments.
You have two great groups based on two great loads as it is.
I would retest for those two loadings only.
GREAT question. To each their own but, i shot each group before moving on to the next. The reason is, if the temp increases as you shoot. the middle group is always "warm but not hot".
Scatter should be 1.5% more or less than accuracy node.
So 1.5% higher than 20.5 = 20.8, 21.1 for next accuracy, then 21.4 for scatter.
Your steps are too large for OCW. OCW should increase 0.5 - 1% per step.
So starting at 20.0, you should use increments of 0.1 - 0.2 grains.
You need to shoot OCW round robin.
This evens out affects of temp and of fouling.
And you should be running at least a full minute between shots to reduce heating.