Powder giving slower MV

[Zigjib]

I'm having some strange results with H4895
I'm loading in my 223 behind a 75gr ELD-M.
My initial ladder test in .1gr increments was;
23.2. 2860
23.3 2880
23.4 2875
23.5 2925
23.6 2905
23.7 2944
23.8 2923
23.9 2962
24.0 2954
24.1 2977

pretty erratic numbers, but i loaded up 23.6 just to see what it'd give me and the mv was 2864fps avg after 5 rounds?????

I loaded some 308 at the same time with the same powder and it gave me the exact mv that it normally does.

So why is the 223 being so weird?

I filled up the hopper on my Chargemaster lite at the start of the week and i've been working with it all week, however i've let it sit in the hopper. I cover it with a blanket and the lid is securely on, as well as the plug fitted over the dropper tube. Whilst i can't say its 100% sealed from the environment, it's not been in the open and the lid has a fairly decent seal.

I can't figure out what's going on? Why are my figures so random for the 223?

 

[BuildingConceptsllc]

Because your actual ES is a lot bigger than you think it is or should be.

 

[Doom]

In 223 a tenth of a grain is worth about 12 fps. If you are very good at reloading you can get a standard deviation bout 10 to 12. What you are seeing with one shot is the random variation of the loads.

Statistically speaking you don't have enough data and your choice of tenth of a grain increment is too small.

 

[918v]

Your case prep…

 

[Zigjib]

In 223 a tenth of a grain is worth about 12 fps. If you are very good at reloading you can get a standard deviation bout 10 to 12. What you are seeing with one shot is the random variation of the loads.

Statistically speaking you don't have enough data and your choice of tenth of a grain increment is too small.

Ah, that's a good way of looking at it. I didn't think about the % of the load and what .1 would equate to.

I normally do .1gr after a .5 grain test to find roughly where i need to be, but i shoot a lot of 308, 6.5, etc etc and this works for those but they have a higher charge weight, so yeah, .1gr is a pretty big % wise for 223 compared to larger cartridges.

I don't reload a lot of 223 so this has been good.

I'll skip to my next phase of load dev and crack straight on with a 5 shot test

Cheers

 

[secondofangle2]