-
If you are having trouble changng your password please click here for help.
Acceptable ES and SD
- Thread starter alexs2006
- Start date
"So it sounds like if ES and SD are under 20 is more than acceptable" What matters is how it prints. If you loop them in like free thrown it matters more than if you fly them flat not as much.
The target don't lie, right? I had one group that was slightly smaller but when I was testing these groups the wind was 15-20mph. So I think the wind was pushing these little 73gr pills around alot.
For me, I would take a 3/4" group with great ES and SD over a 1/2" group but with higher ES and SD. ES and SD don't show much at 100 yards but will when it comes to 400,500,600 yards. 500 is the max my range has. The matches we shoot are at 200 and 400 yards.
At 600yrds a SD below 20 is very desirable. I don't pay attention to it 300yrds and under, in fact I use an rcbs power drop directly into the case for 'short line', 200 and 300yrds. Plus or minus 2 tenths seems not to have an effect. If you're talking about .223 I personally don't shoot projectiles under 75grns short line and 80s at 600. Sun up is the best time to load test before the sun can start convection.
Caliber is 22-250 with 1:8 twist barrel. 73gr are the lightest bullets I'm currently shooting. 69gr SMK's didn't do well at all. I have a supply of 75gr ELD-M's and 88gr ELD-M's I'm going to try. Just wanted to get my reloading sequence back down since it's been a while since I've loaded much. Using new SIG brass for now. I use an auto trickler V4 for all my loads and RCBS match master dies and a RCBS summit to seat bullets. I use the rock chucker for sizing due to it's strength and over all mechanical leverage.
With that cartridge and a bolt gun you'll be able to greatly affect group size with free bore jump, neck sizing/tension and or neck turning. I got sloppy in loading my 80's and over time my seating die setting changed. It wasn't until I actually measured a round and found that I was .015" short, I added that back and greatly reduced group size and increased score and x count. I want to say my SD actually went down as well.
Currently shooting new brass with an expander ball to set neck tension just to get make sure the case mouths are perfectly round. Once all my brass has one firing on them they’ll all get annealed. Shoulder bumped back .020 and will be using a bushing die to set neck tension. Once powder charges are set I’ll start shrinking the groups with COAL measured at the ojive. Currently running COAL .020 off the lands. I’ve already measured my chamber with all the bullets I plan to shoot the most of for seating depth and have the notes recorded in my shooting log book. The rifle is a Win M70 with muller works 26” 1.250” thickness at receiver and .950” I believe at the muzzle. With a jewel trigger and it sits in an HS precision Varmint stock.
