Thread: Obtaining more information from your groups - overlaying groups

I appreciate your thorough efforts in the name of science. Shooter experience would be another interesting variable, but much harder to quantify I imagine.

It's slightly amusing to reflect on my early days of shooting, where 'sighting in' would involve taking one shot, adjusting scope, then taking another. Often I'd be halfway through a box of ammo, and still chasing the zero around the page! Blamed it all on the scope back then.

Originally Posted by whanahuia

You are probably right. It's just that I thought about trying the same experiment you did, by introducing poor performing ammo, or a mix of ammos, to a rifle that performs well. And was unsure of what accurate info that would gain me. I just felt it would be better info to be keeping such variables as ammunition quality etc to the same standard so that you can judge the performance of the rifle.

IE, rather than trying to induce poor performance in a good system, still be trying to produce the best performance in a system that docent historically perform well.

My observation would be that it doesn't seem to be different whether you have an imprecise rifle with ammunition it likes, vs a precise rifle with ammunition it doesn't like - the dispersion characteristics look about the same, which isn't surprising - dispersion is a function of the angular rate and cross velocity of the bullet, and you're just getting slightly different magnitudes and sources of those in either option.

Originally Posted by gimp

My observation would be that it doesn't seem to be different whether you have an imprecise rifle with ammunition it likes, vs a precise rifle with ammunition it doesn't like - the dispersion characteristics look about the same, which isn't surprising - dispersion is a function of the angular rate and cross velocity of the bullet, and you're just getting slightly different magnitudes and sources of those in either option.

This for example is a group from a T3 .223 that usually averages around 2MOA for 10rd groups. The shots labeled 1,2,3 for this particular group were in fact the first 3. Other groups the first 3 are all over the place. At least it's zeroed pretty well.

I guess what you might find with a rifle/ammunition combination known to produce consistently poor 3-shot groups is that it's actually more like a 5-6MOA combination rather than 3-3.5 MOA like this one.

One thing all this highlights to me is that long range shooting for a lot of people is very hit and miss, and probably unethical, excuse the pun. Out past 400 - 500, things must be very sketchy if you don’t have an accurate rifle (by large group size standards). Obviously some people must get lucky and have an accurate system without doing the testing, but even I look back at some shots that were too high or too low or too far back and realise it may not have been shooter error or atmospheric and was actually just the bullet going to the edge of the cone of fire at that point in time. Correct assumption?

Originally Posted by McNotty

One thing all this highlights to me is that long range shooting for a lot of people is very hit and miss, and probably unethical, excuse the pun. Out past 400 - 500, things must be very sketchy if you don’t have an accurate rifle (by large group size standards). Obviously some people must get lucky and have an accurate system without doing the testing, but even I look back at some shots that were too high or too low or too far back and realise it may not have been shooter error or atmospheric and was actually just the bullet going to the edge of the cone of fire at that point in time. Correct assumption?

Yes, although I don't think that rifle precision is often the biggest driver of low hit probability - but having a poor understanding of your precision and your zero leads to real difficulty in attributing error to the correct source.

Here is another go with my 7prc shooting 180 eldm. Was certainly hard getting ten good shots away and good practice. A bit disappointing the one off the bottom. I quite like the ten shot thing, once you start doing it you can see some of the issues with smaller group sizes .

Yes. Im just cautious in that artificially creating the conditions for a test may well skew the data in unknown ways. It might just be me struggling to get my head around it. Superficially there seems to me to be a gulf in process between going after trying to achieve a bad result, and trying to achieve a good result. For example, mentally, shooting a load you know won't shoot well, might in itself effect the result?

As I said I thought about doing similar. I was and probably still am unsure if there is any difference in overall results between using a projectile the barrel doesn't like, and using a barrel projectiles don't like.

Give it a crack with your good load, even

Originally Posted by gimp

Give it a crack with your good load, even

Yeah I intend too. Ive just got a run of work on and every time Im free its been windy as hell.

Hey I'm the original IT dunce but I can't get the Hornardy app to go on my phone and I can't see how to get individual shot data from ballistic X. And other ideas on what app to use?

Originally Posted by Tentman

Hey I'm the original IT dunce but I can't get the Hornardy app to go on my phone and I can't see how to get individual shot data from ballistic X. And other ideas on what app to use?

Ah. If the Hornady App doesn't work I'm not sure there are any others. I didn't realise BallisticX doesn't give you shot co-ords.

@Tentman if you take good flat/square photos of your targets and send me those & the details I can Hornady App them for you

Originally Posted by gimp

@Tentman if you take good flat/square photos of your targets and send me those & the details I can Hornady App them for you

After a bit of pissing about its now operational on my tablet, so I can get started.

Ive actually just put a scope on a rifle that I think will benefit from your approach @gimp. Ive had it for a long time. 280AI, and its never grouped well. But it doesn't shoot bad. In fact ive noticed that while the 100 yard groups can be discouraging, it doesn't seem to equate too worse performance at distance, rather the opposite.
So thinking about it, in this case sighting in at 100, it could potentially benefit from going through the mean radius process to ensure its being centered properly. Its one rifle I never trusted on a 3 shot group anyway.