Basic Reloading/Round Workup Direction

[Paulyester]

Just starting to reload my own bullets. After some newbie bumps and bruises, I'm finally getting into a groove preparing my brass so that they are all consistent. Now I need to make a load for my rifle. 6.5 Creedmoor, Outlier 26" barrel.

What is my goal of working up different rounds? Say I have 50 rounds worked up, 5 shots with each charge, I go out and shoot and chronograph them, am I only concerned about ES and SD to begin with, or do you factor in where they are hitting on the target as well? For example, if I have a load that produces a 9FPS ES and 4 FPS SD, but shoots 1.4 MOA at 100 yards and another load that shoots 20 FPS ES and 10 SD but shoots .4 MOA, which one do I work with? Do I go with the best SD and then start playing with seating depth?

Any advice on the process would be appreciated

 

[918v]

Take the low sd load and try different seating depths.

 

[Rocketmandb]

A lot is dependent on what you intend to do with the rifle. If it's going to be a 100-yard range rifle, then SDs don't really matter. Find the best combination of SDs and group size then tune seating depth to bring in the groups more.

OR - if you're going to be going for longer ranges, then do what @918v says.

OR - if you just enjoy optimizing, then also do what @918v says.

 

[Rocketmandb]

For example, if I have a load that produces a 9FPS ES and 4 FPS SD, but shoots 1.4 MOA at 100 yards and another load that shoots 20 FPS ES and 10 SD but shoots .4 MOA, which one do I work with? Do I go with the best SD and then start playing with seating depth?

One other thing - don't assume that a 9 FPS ES/4 FPS SD load will hold up - or even be the best performing load - after only 5 rounds. You need to find a couple of the best performing loads, then validate them over 20ish shots.

 

[Paulyester]

A lot is dependent on what you intend to do with the rifle. If it's going to be a 100-yard range rifle, then SDs don't really matter. Find the best combination of SDs and group size then tune seating depth to bring in the groups more.

OR - if you're going to be going for longer ranges, then do what @918v says.

OR - if you just enjoy optimizing, then also do what @918v says.

Great question. One rifle will be used for long range only, 700 yards plus, the other I'm building for NRL Hunter matches so longerish ranges as well.

 

[KYAggie]

I see this quite frequently in load development where I have the best group exhibiting the worst SD, often around 20 and the low single digit SD group being the worst. Like someone else already said, three or even five shot groups are not really statistically significant; only indicators or what could be. I typically pick the smallest SD charge to load and then do a seating depth test. It’s always interesting to me how much seating depth affects ES and SD too. I recently tried a different method to test a bullets preferred seating depth by loading rounds starting .01” off in .005” increments to .10” off, 1 round each, shot them on a target 500 yards away and recorded the vertical difference from the first round on target. It was eye opening. None of the rounds were below the first and there was a spot on the chart where the differences between shots from seating depth .04 to .06 were only .2” different elevation wise from each other and around 3” above the first shot. I would say that’s where I’ll seat that bullet. The rest were all over the place elevation wise from 1” to 7” above the original shot.

I’m not authority on this stuff, just someone having fun trying different things and learning from it.