I need some reloading guidance concerning ES SD

[waveslayer]

Those ES and SD's will hurt you out past 500! Something is way off.

Read about a OCW test for reloading and finding your preferred load.

Any SD over 10 is bad. If I can get my SD to single digits I know I'm in my node.
ES will naturally be very low as well.

I have my .338 Norma Magnum AI down to an SD of 1-3. Mostly 1. So it is possible

 

[436]

I could use some guidance as to what I need to do next in my reloading process/equipment to get my SD and ES down. Where I live 400 yards across a hay field is a solid poke, so I know worrying about these numbers isn't a huge deal for me the vast majority of the time. That said, I like the idea of precision reloading, and I do occasionally get the opportunity to travel and hunt where longer shots become more of an option. Both rifles are consistent 1/2 moa shooters at 100 yards, so I had always assumed I was good to go. Until I recently bought a chronograph...

Rifle #1 Ruger M77 220 Swift heavy barrel (tang safety) w/ Nikon Monarch 6-24x
Shooting Nosler 55 gr Varmagedon @ .020 off lands
Federal GM210M primers
Norma brass
H380 @ 39.5 gr giving me 3630 fps.
SD 40 ES 33

Rifle #2 Cooper M52 Excalibur 280 AI w/ Leupold VX6 3-18x
140 gr Nosler Accubond
Fed GM210M
Nosler brass
H4831SC @ 61.5 gr giving me 3105 fps
SD 46 ES 60

I use the same reloading process for both rifles. Cases are FL resized using Redding FL sizer and their competition shellholder sets. I've got a Wilson case trimmer for that task. Cases all get primer pocket and flash holes uniformed, deburred/chamferred, inside of the neck brushed out. Both have micrometer seating dies, the Cooper a Redding, and Forster for the Swift. Powder charges are thrown low and trickled up to the desired weight using an RCBS 10-10 scale. I've got a Caldwell chronograph. It's relatively cheap, but got pretty good reviews.

Life was too busy this year to do anything other than hunt WT locally. The load I have will work just fine for that. Next year I've started planning an antelope hunt with a couple friends. I would like to have things straightened out before then.

Well, not too sure about your 280 AI'..., but the .220 Swift I might be of some help. Nosler listed a load for the 55gr ballistic tip in their reloader guide number Four page 156... which I started using many years back. It was; (37.0grs) of RL-15 with 3980 fps. Well, I had a Remington M-700 SS in a 26" barrel that would come close, with absolutely no sign of pressure and pretty darn good accuracy. So, I started pushing the load up a little at a time and saw the velocity come up to the 3980 fps when I got to (39.0grs) it was just over 4000 fps with one hole type accuracy along with SD's and ED's as low as I've ever seen them in the .220 Swift's I've owned. Weather temps were not a big factor in my rifle.

Case: Win
Primer: CCI BR-2
Powder: RL-15 (39.0grs)
Bullet: Nosler Ballistic Tip 55gr BT
WARNING: This load is over Max... work up slow "any" indication of pressure stop!

 

[bigbulls]

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[Dbranch]

Simplest way without changing much would be anneal your brass to help with neck tension recheck seating depth and overall length. Then take it out and shoot some distance to see how it holds up. If that doesnt work I would play with seating depth but you maybe limited by mag length