Hit percentage analysis

[bruce_ventura]

Bryan,

Thanks for posting this link. I use Monte Carlo analysis frequently at work. It's great to see this tool integrated with a ballistic solver that's available to recreational shooters. The PRB article shows how useful this type of analysis can be to the long range shooter. The implications are pretty sobering, actually.

I usually try to do a rough estimate of probability of hit by running quick sensitivity analyses using my ballistic software, and then combining results using a root sum of squares. Your WEZ software is a MUCH BETTER way of doing this type of analysis. It's faster and more accurate.

 

[CB11WYO]

Now apply a time and cost model to chase a rifle from 1 MOA to .1 MOA and one might really see what diminishing returns are all about.

Yeah, I mean if you've got a need for .1 MOA and money to burn then why not i guess, but this just adds some good perspective.

I've always wondered the same about costs. Like, to get to 1 MOA from 2 MOA costs "x"... from there to 1/2 MOA costs "2x"... from there to 1/4 MOA costs "3x"...

Those ^^ aren't real #'s of course but I've always pictured a similar equation in my brain as far as costs are concerned. Then of course there's ALWAYS an exception to the rule

 

[16Bore]

I'd love to see the analysis with 1/2 MOA vs 1 MOA groups with a 5" target at 500. I'd expect the gap to be a tad wider. The world may never know and I'm probably not going to pony up $200 for software.

As for cost and diminishing returns, I've found that a solid factory rig can easily be a 1/2 MOA shooter if well stocked and decent load development. 500 is all I play and staying "short" helps to keep the wallet full. There have been days when 1/2 MOA groups were easier to come by than others, but lotsa factors change. Can't say I could pull it off in harsh conditions or with a funky rest. But I tend to try to focus more on the knucklehead squeezing the trigger than trying to buy groups.

It's kinda how Callaway can sell a $500 driver. Maybe when I'm too old to shoot I can find one at a pawn shop for $25....

 

[bruce_ventura]

...we divide the user input for 'rifle groups' by 4, and use that as the standard deviation of that parameter. By dividing by 4, we're capturing +/- 2 SD's, which is 95%, or 19/20. Seeing as how most shot groups are under 20 shots, 95% is essentially 100% for 3 or 5 shot groups. This was done to ease misuse of the interface. Shooters don't know the SD of their groups, but they do know CTC...

I just noticed this detail. I think that dividing ES by 4 to get SD is only valid for groups of >20 shots. However, most shooters base their ES off of 3-5 shot groups. On average they end up with an ES value that's smaller than what they would have gotten with a larger number of shots in the group. For example, the ES value for a 4-shot group should be divided by about 2 to get the SD.

That means that most shooters should multiply their ES values by 2 before entering that data into the WEZ software. In the graphs in the PRB article, the MOA values shown along the X-axis should be divided by 2 to get ES values that correspond to a 4-shot group. That change makes the graphs appear a bit more reasonable.

 

[Greyfox]

Thanks Byan! Your books have been my constant companions since I bought them a few years ago and they have made a material difference with my long range hunting and shooting success. The WEZ concept is one that I place major emphasis on. Given enough time and experience in this sport and putting all the concepts into practice, I find myself now focussed on what you describe as the "non-deterministic" factors of wind, and ES(the cartridge). I think I have reached a high confidence level with my ES falling between 5-10FPS, but if I miss a target, or pass on a shot at game it is invariably due to wind uncertainty, as your diagrams always reflect. perhaps you are thinking of an upcoming book on the subjectlightbulb

 

[DocB]

Great post, and that makes perfect sense. I like your idea as far as building a rifle to the specifications needed. You could also try to tailor loads to fit this criteria.

Absolutely +1!

As my mentor told me not so long ago, "WEZ analysis will represent an entire paradigm shift for the long range shooter and hunter". He read your book Brian!

This kinda stuff is why I love this site!

Thanks guys!! DocB

 

[pyroducksx3]

But what good is all of this if I can't have the info when I'm shooting. I understand I can bring data back and figure stuff out but I really feel this is info needed in the field. Hopefully the mob version will be released for civilian use soon as I know there is a mobile version for LE and military

 

[MMERSS]

Uh oh... I think I'm an egg-head

you gotta be somewhat of an egg-head to think it's interesting to begin with.

HA! Me too.

 

[MMERSS]

I see Cal finished up the series. IMO, this is one of the best blogs relating to the pursuit for accuracy out there. Fabulous work!

 

[Cold Trigger Finger]

My take away was. Now that I know I have a su .5 moa rifle and load. To just go learn the wind. And shoot and shoot and shoot. The blog articulates what I've thot for the past 3 years.
Find the rifle, round and optic that will do the job I want done on the game I will shoot with it. Then learn to shoot well enough in the conditions I will hunt in.
I posted the blog link in the 6.5 Creedmoor forum yesterday around noon as I am on the PRS email list. He did a great job on his high end scope review.