Depends on group size. See how it shoots at 1-300 yards. Going for velocity or accuracy?

Why is the velocity so important if you are after a small group size?

Let the velocity be whatever it is for the most accurate load. (as determined by group size)

+1

If you have a chrono go for lowest SD first before evaluating group size, and use 10 shot sample sizes focusing on group median radius (average to center) rather than extreme spread (largest distance measured between 2 shots).

I think you're correct about your current SD, not a bad start for 55g loads, as good or better than what I've seen from commercial "match" ammo.

I hope I'm not hijacking the thread, but I'm new to load development and want to validate my thoughts here:

Tight groups come from the bullet exiting the barrel at the right time (accuracy node). The time that the bullet exits the barrel is based on the muzzle velocity, which is based on the powder charge. If this is all true, than a consistent point of aim with a consistent projectile at a consistent speed will result in a consistent point of impact.

The SD and ES of a load over a chrono is driven by consistency of loading that specific cartridge. Brass prep, powder measurement, projectile screening, neck tension, etc. Identical cartridges should produce identical velocities under identical conditions. Inconsistency in cartridge preparation will lead to inconsistency in velocity and a lack of predictable drop from shot to shot, and thus larger groups.

Is all of that correct, or, things like barrel heating aside, is there a relationship between the SD and ES of a load and the gun itself?

If my understanding is correct, then MV and identification of an accuracy node are addressed during load development and then SD and ES of the load are addressed by eliminating variables during the loading process itself.

Please define the term "accuracy node" I have never seen it used before.

This is a decent explanation, an accuracy node is a crossover point in barrel whip during firing, also a point where a load demonstrates consistency in performance for a range above and below the charge, to give maximum latitude for velocity differences. It's a factor in Optimal Charge Weight (Dan Newberry), Optimal Barrel Time and even ladder load development techniques.

https://loadoutroom.com/thearmsguide/long-range-shooting-barrel-vibration-accuracy/

Thank you, that was my first thought, but the term was a new one.

It sounds like a bit of a stretch, and something dreamed up to just have a catchy name for a well known phenomenon, but now I know what it means.

Thanks again.

Be careful with reloading at this point. What happens is you keep chasing chrono numbers trying to es and sd and when their not what you expect you'll spend money on more shit to fix it. Aim for one moa at 100 yard increments out to 1000, I stopped there and am happy.

2 load development videos worth watching >>>

1) 8541 Tactical / John McQuay >>> 12 round ladder test - LINK

2) 6.5 Guys >>> 10 round load development ladder test - LINK

P.S.: Sort cases by headstamp but not weight.

+1 Yes, the information in this video will save you a lot of load development time *if you use a good chrono* like the Magnetospeed or Labradar.