Down the rabbit hole

[motzboss1991]

Wondering if I should be chasing SD or grouping. I thought I had my load down the second visit to the range. Gun grouped well at 100 and 200 yards (for me) However, when I input the data into excel, a less performing load had a measurably better SD. Should I keep tinkering with it or call 69 grains good enough.

7mm Rem mag, 180 grain Bergers, hunting VLD.

 

[45-90]

Depends on what you are pursuing. In a short to medium range high velocity cartridge, group size might be more important, say for varmints.
Long range target, at 1000 yds velocity spreads need to be of concern as well as group size, to be able to consistently hit your target.
Hunting large game could be more velocity, with slightly less accuracy to have more energy arrive at the animals vitals to improve bullet performance, for a fast kill.

 

[motzboss1991]

This is a hunting load. I’d like to be able to take shoots at 400 yards with confidence

 

[memilanuk]

This is a hunting load. I’d like to be able to take shoots at 400 yards with confidence

Stick with group size, for those purposes. I mean, if the SD gets really bad, try to find and fix the problem... but for what you're looking for, stick with group size. The SD would have to be truly horrible to be a dominant factor at that distance.

 

[45-90]

For 400 yds any load that shoots 5 into 2" is good enough, but 1" to 1.5" would be all the confidence ya need for big game its a large target, with a large vital area.
When young I had a 30-06 with iron sights.

You should practice off hand from 35 to 100 yds, shoot jackrabbit sitting and running with your big game rifle. Also shoot from the sitting position for longer shots.

Every head of big game I killed off hand except one, if you actually hunt them on foot instead of from a blind or ambush.
I used light factory rifles, with 24" barrels for this with hand loads, first was a 7 Rem mm mag a 1" shooter, then later a 338 Win mag, 1 to 1.25" shooter for all big game, I even used factory 2nds bullets to kill deer, probably 95% were 100 yds or less.
No range finder, bipod, or weighty electronic crap.
Carry 1 large, sharp, fixed blade knife like a Buck Special, or KBar, a fire starter, and compass.
Travel light, it's gonna be a very long hike...even worse if you kill an elk on foot, miles inside a wilderness area, alone.

 

[The_Steward]

I'd shoot the 68.8's. That 200yd group could be due to all kinds of stuff. At 100yds they are basically the same, and the SD's aren't affected by wind or you pulling shots.

 

[JB.IC]

I don’t think group dispersion and MV dispersion will show an obvious covariance structure at 100 or 200 yards. Maybe if your MV SD was like 60fps, then it might show up at 200yds assuming group dispersion was small before the increase in MV SD. Since group dispersion and MV dispersion are random variables with no obvious covariance structure at say 200 yards or less, it would be hard to draw a conclusion about their dependence.

So, improved group precision would get my vote at those ranges. At extended ranges, you have to care about both.