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Posted By: tcp Litz WEZ calculator - 10/05/16
I would be interested to see the difference in hit probability between a 1.5 MOA rifle and a 0.5 MOA rifle, all other variables held constant, at 500 yards using the Applied Ballistics app.

Just curious as to how many pounds of powder and bullets are worth burning up in load development to improve on a load vs. the increased hit probability achieved with the gain in accuracy?

Thanks
Posted By: Dogshooter Re: Litz WEZ calculator - 10/05/16
Ask.... and ye shall receive...

Precision Rifle Blog: Does group size matter?

Link to the discussion here....

24HCF Group Size Discussion

Posted By: tcp Re: Litz WEZ calculator - 10/06/16
Thank you, but...it was my having found and read the linked article that prompted me to ask the question here. Vaguely, I recall several years ago a similar hit calculator was free on line at JBM ballistics but I can no longer find it.

For my practical purposes, I was looking for the difference hit probability between a 1.5 MOA rifle(the one I have) and a half MOA rifle(the one I would like to have) on a 2 MOA target at 500 yards.

Extrapolating from the graphed data in the linked article, I suspect that the gains between 1.5 MOA accuracy and .75 MOA accuracy are fairly great- particularly at ranges under 600 yards.

Again, thank you for the response. And, if someone has the software and is willing to run the simulation I would appreciate it.
Posted By: Carl_Ross Re: Litz WEZ calculator - 10/06/16
In order to run a simulation like that, you need some uncertainty info. I put in +/- 5 yards on the range, +/- 3mph on the wind call, and a velocity SD of 10 fps and ran a similar one. 99% on the .5 moa gun and 95% on the 1.5 moa gun.
Posted By: BobinNH Re: Litz WEZ calculator - 10/06/16
Originally Posted by Dogshooter
Ask.... and ye shall receive...

Precision Rifle Blog: Does group size matter?

Link to the discussion here....

24HCF Group Size Discussion



Those were good articles. Interesting.
Posted By: Dogshooter Re: Litz WEZ calculator - 10/06/16
Originally Posted by Carl_Ross
In order to run a simulation like that, you need some uncertainty info. I put in +/- 5 yards on the range, +/- 3mph on the wind call, and a velocity SD of 10 fps and ran a similar one. 99% on the .5 moa gun and 95% on the 1.5 moa gun.


Pretty easy to get ANY rifle to shoot 1.5" consistently.... in fact, I suspect most ".5 MOA" guns are probably more like 1-1.5 MOA guns over the span of 25-50 rounds.

A 4% delta for all the effort it takes to build and develop a true .5 MOA gun/load seems like a lot of work for a slight gain. Particularly when the 1.5" gun still makes hits at a 95% clip. Something about "diminishing returns" is applicable here.
Posted By: dodgefan Re: Litz WEZ calculator - 10/06/16
For most of us chasing that last little bit of accuracy is time and money wasted IMO. Learning to call winds accurately is where the big dividends are at. All the top shooters I've met had the ability to call wind in common.

I've shot the Sporting Rifle Match, F-Class and prone matches in Raton and my rifles are accurate enough, but my wind calling skills are lacking. My scores were decent when the wind died down or held constant, but when the wind is gusting my scores dropped.

Posted By: Carl_Ross Re: Litz WEZ calculator - 10/06/16
For the competitions I shoot, if your hitting 1 moa consistently your probably good enough. 1.5 moa wouldn't hold you back too much, it'd depend a lot on the target size. Some matches have BIG targets, others not so much.
Posted By: Carl_Ross Re: Litz WEZ calculator - 10/06/16
Also, when I say 1 moa I mean 19/20 on a 1 moa target. Which I'm guessing is also what the simulation means.
Posted By: tcp Re: Litz WEZ calculator - 10/06/16
Thank you for the replies.

Carl Ross- what was the target size you specified for the simulator? I am surprised that a 1.5 MOA rifle would achieve a 95% hit rate at 500 yards.

Thanks
Posted By: Carl_Ross Re: Litz WEZ calculator - 10/06/16
10.4 inches. If I shrink it down to 7.8 inches (1.5 MOA), hits only drops to 84%.

Also I'm not using the Litz software. I'm using an android app, External Ballistics Calculator. It has a Monte Carlo simulation option, not as powerful as the Litz one, but it's only $7. Worth it to me to play around with.

Also, that was for a 7mm 180 Berger at 2800 fps, which is no slouch in the ballistic department.
Posted By: Carl_Ross Re: Litz WEZ calculator - 10/06/16
Just cause I was curious, I ran the same parameters with a .224" 50gr Vmax at 3400 fps.

.5 MOA gun was 66%
1.5 MOA gun was 61%
Posted By: tcp Re: Litz WEZ calculator - 10/06/16
Carl Ross, thank you again. It would appear that a rifle that is not quite MOA is good enough for my needs and the last several hundred rounds spent developing a "better" load has largely been a waste of time.

On to other pursuits.
Posted By: Grand Re: Litz WEZ calculator - 10/07/16
Sounds like you got your answer. I would add that target size is critical in understanding whether MOA accuracy is good enough. On small targets like ground squirrels and PD's, the margin of error is much smaller and the difference between MOA and 1/2 MOA at 300 yards is the difference between a hit and a miss.
I ran it on AB Analytics for a 10" target (deer vitals) at 500m using an MV SD of 10fps, wind at plus or minus 1mph which is way better than most can judge, and range at plus or minus 1m assuming you have a good LRF.

Work Guns

.223 Rem with 77gn SMK
.5MoA = 97.9
1.5MoA = 83.1%

.308 Win with 175gn SMK
.5MoA = 99.6%
1.5MoA = 86.7%

.300 Win Mag with 190gn SMK
.5MoA = 100%
1.5MoA = 88.9%

Hunting and Match Guns

7mm Rem Mag with 162gn A-MAX
.5MoA = 100%
1.5MoA = 89.8%

6.5 Creedmoor with 140gn ELD
.5MoA = 100%
1.5MoA = 89.2%

On average it models as a 10-15% difference between levels of precision.
Posted By: tcp Re: Litz WEZ calculator - 10/08/16
Thank you again. I would be interested in the results with a less accurate wind judgment as 2-3 mph is more in line with my ability.
You can sort of judge the others off these. Only change was that I changed wind call to 3mph on wind:

.308 Win

.5MoA = 73.8%
1.5MoA = 62.3%

6.5 Creed

.5MoA = 87.1%
1.5MoA = 72.9%

7mm Rem Mag

.5MoA = 90.9%
1.5MoA = 76.2

So, for me, the money spent is worth it on a gun that will shoot sub-MoA but you can't beat wind by spending money or shooting a whiz bang round. Get/build a decent gun with a good optic and shoot the piss out of it.
Posted By: tcp Re: Litz WEZ calculator - 10/08/16
Thank you, again- very enlightening.
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