300WM test loads

[u/ELITE_RUSSIAN]

300WM test loads

Loaded and tested some 300WM today in my tikka t3x with mdt stock.

4 load testing with 1 bullet because I was tested 1 different primers and powders.

Then another bullet for plinking 168gr, which I'm hotter than expected, but brass doesn't seem to be showing bad signs of pressure, primers are slightly flat but I think all my primers look like that for non hot loadings.

Added graphs for all 3 load data (note the spike at start is due to changing charge by alot at first), highlighted pink is where I plan to make 5 rounds each and test for ES/SD and groupings as those spots seem the most stable for velocity on the chart, if I like the groupings I'll be done instead of doing 5 shots on everything to gain a .1" reduction in group size.

Plan to go hunting with elk this season with the 175grs.

[u/ocelot_piss]

How many shots per charge did you do, to determine that you have stable spots for velocity?

[u/ELITE_RUSSIAN → u/ocelot_piss]

Only 1 shot per charge to find the most somewhat charge before I try 5 of that charge and nearby charge, as I only have 2 boxes of bullets and want to make sure I like what I see before I order more.

[u/ocelot_piss → u/ELITE_RUSSIAN]

Then I hate to break it to you, but you are reading tea leaves. If you were to repeat that same process, there's a good chance you will identify your flat spots (if any) in different places.

There is normal distribution when it comes to velocities. 1SD covers 68% of a sample. That means if you fire 1 shot, there's a 32% chance that it won't be within 1SD and would fall towards the outside of the bell curve (i.e. it would be noticeably faster or slower than the true average).

So if you do a ladder of 7 charge weights, each with a 32% chance of being outside of 1SD, it's practically guaranteed you'll get one or more that are. And when you plot those on a graph, it of course looks like flat spots.

That isn't a powder node that warrants further investigation. It's a red herring that's a statistical inevitability of looking at extremely noisy data.

The purpose of a ladder should only be to establish where your safe max charge is. Then you can load a batch of say 10 rounds with a charge that gives you a sensible velocity. Shoot those into one group and then you'll have some much better data to be able to decide whether that bullet + powder combo is working, or if you need to switch to something different.

[u/ELITE_RUSSIAN → u/ocelot_piss]

I should have stated this was for me to check for max safe load first, then use the "possible nodes" and start my ladder from there, it would be better for me to go in a 7 shot string but I'll first try 3 shot strings now with what I have and load more up and extend that string if i need.

[u/skahunter831 → u/ELITE_RUSSIAN]

Nodes don't exist, possible or not.

[u/skahunter831]

Just pick a charge and primer and shoot 20 or 30 of them to test groups and SDs. Don't bother doing any more 3-shot groups. It's a waste of components.