Home Forums Reloading Big Game Rifles Amazing difference in group size at 200 yards.

Loaded 3 different loads, each with .5 gr more R22. 51, 51.5, 52 gr. 143 eldx, 6.5-06.
5 shot groups. Bumped up the point of impact 3” on the last grouping to get zeroed. I’ve never had such a group size discrepancy, so suddenly, in working up loads. Loads went from 3+“ at 200 yards to .70” at 200 with the 52 gr. load. Any of you seen something similar?

Eventually l snake my barrel and it comes back. If not go over the rifle.

When working up loads, I do it at 100 yards. That way wind doesn't have as much of an effect on the groups. Even at 200 yards, it has much more of an effect and can mislead your results. During load work up, yes I've seen charge weights effect the group size. Even a 1/2 grain charge can shrink or open groups by a lot. That is exactly why we work up loads.

Your worst group is 1 1/2 moa, your best group is .33 moa. So, Yes, I've seen it. But again at 100 yards. Because of the wind, I don't like to mess with working up loads at 200+ yards. It's up to you though, but you can get some pretty skewed results working where the wind is going to bite you in the butt.

Also, at further distance you are or may be dealing with a parallax issue and an enhanced shooter error issue (if there is one). Some guys may look at your groups and say there's no indication of wind, what is he talking about. Those guys have never shot with extreme headwind or tail wind or evaluated group dispersion either. You'll see headwind and tailwind compounds group size the further out your target is too.

Recently I was working with a new rifle and I got some really weird/wonky groups. Keeping in mind this is a worked up proven load. The first 5 shots at 100 to confirm went into 1 moa. The second group at 200 was a little over moa, the third group (at 300 yards) was .8 moa and the last group fired at 400 yards was only 1/2 moa. All groups (200-400 yards) roughly the same size when measured. How does that happen??? That's an anomaly that is hard to explain. Your groupings, not so much. The first one screams too light of a load (wants more powder), the second seems charge weight was too light plus wind may have effected the group, could have also been shooter input that threw a couple shots too. But there is really not nearly enough groups shot to evaluate any kind of a rational explanation.

Personally, I'd step it back to 100. Re test those loads and see what they tell you. If that 52gr charge load is driving tacks again, re test at 200. If it's consistent, go with it. That's a pretty damn nice group at 200 yards.

BSA, good feedback. Thank you.

In my experience, even with a tight group at a hundred wind is still an issue at 200. POA plays into it as well. I use a diamond target that improve POA and POI. Watched a pod cast from Hornady about thier ELDX wondering how it would fair beyond 300 yards.

I take it a step further and do initial development at 50 yds. Besides the wind issue, I'm working these loads up in the rifles that I hunt with and the optics are typically 2.5-8X36 max
Once I can shoot consistent 3 shot bug holes with a load, than I'll move it out to 100/200 and see how it does.

That doesn't seem to be a very efficient use of limited-supply components.

This is what happens when you have a "whippy" barrel and you find a vibration node. The bullet exits when the barrel movement is at a minimum. Like BSA said, you need to re-test to confirm previous results.

I've used a lot of Re22 in many calibers. Mostly, Re22 loads have shot best at or near max. The same as all slow burners I've tried.

Yep I have seen it. 25.06, 52.5 grains RL22 and 110 AB shot at 200 yards. I already knew powder charge so this was seating changes, but powder charge variation does the same.



And whether working at 100, 200 or 300 wind flags are your friend.

This is another worthy piece of Information that's worth considering.

Seen it many times with RL22. It's a magnum, slow burning powder, when it gets into it's range it typically comes alive. Great stuff.

RatherBHuntin,

Is 52 gr the max with that powder/bullet or where you at with that?

If there was still a margin of safety, it would have been interesting to see what a 52.5 grain load would have done.

Yep

You're seeing statistical noise. Like ghosts in fog bank.

You might search for the Hornady Podcast episode "Your groups are too small".

They ran a bunch of experiments with groups up to 500 rounds. Short summary.

- Group sizes generally don't get bigger after 50 shots but may not be entirely circular.

- Groups are usually circular by 100 rounds.

- The data suggests you need groups of 35 to predict which load is better (statistical significance).

- Groups of 20 are usually predictive but not always.

- Generally speaking, stick powders are usually more accurate than ball powders.

- Different barrels like different bullets and different powder.

- GROUP SIZE (dispersion) INCREASES WITH VELOCITY!! THEY COULD NOT FIND "VELOCITY NODES" OR "ACCURACY NODES" WITH GROUPS OF 35 OR MORE SHOTS.

-Bottom line, for hunting, pick a bullet type and stick powder with a good reputation for the cartridge. Select the slowest safe load that will deliver the bullet at your target distance at a speed sufficient for terminal performance (eg, 1800 fps for many traditional cup and core bullets). Shoot 20 (or more) shots in a manner that replicated your use. For hunting with a light barrel, 7 or 8 3-shot strings on thr same target allowing the barrel to cool, will give you 21-24 shot replicating a common hunting scenario. If the result is sufficiently good, don't keep looking for something better. If it's not, try a different powder or a different bullet.

Like many people here, I've stared at 3 shot groups like a medium reading tea leaves. In a former life, I taught stats and am convinced the Hornady approach is sound.

I no longer chase accuracy nodes and simply load for just enough velocity.

Well you're no fun

I’m likin Hornady casts

I buy into your post 100%. I would add one more piece of wood to this fire. A few years ago, I got interested in something a poster here suggested concerning true hunting rifles only. 1 cold barrel shot a day for a week or two...just to see what your rifle can do in a real world cold barrel shot found in hunting. It's a real eye opener, rifles that I considered, yawn ho-hum accuracy in prolonged bench sessions...in some cases turned out to be...old reliable.

That 3rd, or 5th, shot is so often the deciding factor in whether an animal is taken or lost.