Home Forums Hunting & Shooting Ask The Gunwriters Acceptable accuracy , out to 400 yards

Casey,

Obviously I’m not John, but the point of shooting more shots into the group is not to test how the barrel handles heat (that’s a separate experiment), but to understand the statistical distribution of shots fired under the same conditions. For a hunting rifle, it would ideally test the statistical distribution of cold-bore shots, so allowing the barrel to fully cool between each shot wouldn’t be a bad thing. So two separate 3-shot groups fired into the same target is essentially a 6-shot group, in the context of testing your rifle/load’s precision.

learn your rifles potential with the load you're going to use. then go shoot a few rounds of NRA high power silhouettes. this is a totally offhand game you will be humbled. then maybe try some bench work off of a bipod and other positions and you'll get the idea of what field position accuracy may be.

I understand you meant 1" at 100 yards.

The factors which cause what you're talking about can also swamp the difference between 3/4" and 1" loads at 100 yards when they're stretched to 400.

Jordan Smith, Good point. There is actually a small lunatic fringe of rifleman, prior to a remote or expensive hunt that will go out and shoot one or two shots a day at the same target for a few days in succession....some say lunacy, some say exploring the finer points of Murphy's Law.

Jordan,
That's what I was wondering if two, 3 shot groups would still be statistically valid as a 5 shot group. I'm doing this because of throat erosion rather than first shot, cold shot POI. Thanks!

I do this quite often, the 3 shot group, another the next day, etc, etc, etc. I'd much rather do that than wail away with 10 shot strings at the same sitting. Since I've never shot more than 3 times at any game animal in my 51 years of hunting, I'll probably keep doing it that way. I am with jwp though.......1st round cold bore hits is where it's at.

If that's the standard, then shoot something like ten cold bore shots on the same target.

I agree, once I get a load grouping well that's the next thing I check. As an example my 308 Mtn rifle HATES a clean bore, or even a slightly fouled bore--it can shoot as much as 3 1/2" high with a sparkling clean, cold bore, compared to a well fouled bore.

I set out a 12" circle at 600 yards getting ready for an elk hunt. I shot 1 shot and left, three days latter I shot 1 shot, 4 days latter I came back and fired 1 shot. I then gathered the target and had 3 shot in just under 2" at 600 yards
I figured that was good to go

I'd rather do multiple 3 shot groups if that's ok with you. ;After load development they're always around 1/2" anyway.

I’d say so!

We keep 1.5-2MOA stenciled circles on our gongs at 300/400yds and I like my rifles to keep the cold bore shots in there. Some do a fair bit better. I often bring a half dozen rifles to the range and only shoot a couple rounds through each at those gongs. Saturday morning I drove down to re-paint them afterwards and counted 11 out of 11 hits in the circles. They’d have all been kills on a deer. We also shoot a lot at life-sized hog gongs at 200/300yds, as it’s good fun and practice for the sort of hunting we do.

I’m not fond of 100yd paper, beyond seeing if a load will group half decent and is relatively zeroed.

Regardless of what some here think, you're rifle will be fine (just not great) but the real question is, will you be capable at that range?

Your limitations magnify whatever the guns limitations are, & vice versa.

No substitute for practice.

MM

Actually, the best way would be to have 2 or 3 targets - a first shot target, a second shot target, and if desired, a third shot target. Seven to ten range sessions with no wind (or as close to no wind as you can get in your locale) because you're assessing the gun and load combination, not your wind reading and compensation abilities. First shot (cold bore) into its target every time, second shot into its target every time, etc. Software is available to analyze the targets and provide statistics, or you could do the analysis by hand or in a spreadsheet.

You can analyze each shot in the shot string separately and see if there's any difference among the first, second, and third in order. You could do an aggregate group at any time with any set of the 14 to 30 shots (e.g., sort by ambient temperature ranges). You could even go beyond ten range sessions and get longer-term data. The minimum I would do to draw even preliminary conclusions would be three range sessions with first shot and second shot targets.

Separate topic related to wind effects:
First time I ever shot at 600 yards was an eye opener, but I didn't realize at first what I was seeing. The vertical dispersion wasn't bad - about what one would extrapolate from groups at 100 and 200 yards. However, the horizontal dispersion was awful, and what I didn't realize immediately was that even the very light breeze had a tremendous effect at 600 yards (and from more experience I found wind effects are still very noticeable even at half that distance). Therefore, eliminating wind effects to the extent possible is absolutely critical to assessing a rifle's and load's capabilities.

It's more valid, in terms of representing your rifle/load's true precision, than a single 5-shot group.

What type of big game? Vital area size is part of the equation. For pronghorn or deer, I would probably try for 0.75" at 100 yds. For elk, the vitals are larger, and your load is probably good enough.

I was just rolling with the first round, cold bore theme.

This.

I *think* for a constant cross breeze the deflection grows a bit more than quadratic with distance.

I'm going to disagree. I think it's exactly quadratic.

Don't forget impact velocity