Ballistic program is way off compared to actual shot.

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Crouchy

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So here is my issue. I am shooting a savage mkII fv (heavy barrel) with a diamondback tactical (milmil) on top. I have plugged everything I can as accurately as possible into strelok and two other ballistics programs. I shot 30 rounds over a chrony and entered the average velocity. Now it tells me I should see the following drops from a 50 yard zero:
This is all for SK rifle match which says it should be 1070 fps. I had an average velocity of 1000 fps.

25 yards - .4 down
100 yards - 1.9 up
150 yards - 4.4 up
200 yards - 7.2 up
300 yards - 13.4 up

I shot a tall target one day and got the following drops measured off of ten round groups: (both days where almost identical temp and pressure... only slight cross wind but I set up to have perfect 9 o'clock wind.... so I only measured the vertical displacement.)

25 yards - .5 down
100 yards - 2.65 up
150 yards - 6.1 up
200 yards - 10.8 up
300 yards - 20 up

Now yesterday I shot in a CRPS (canadian rimfire presicion shoot) at east elgin near london. it was awesome. However I was frustrated by my dope almost all day. I wasn't able to plug the wind into my app and get reliable dope. When there was no wind I could make hits (using my confirmed distances I shot). But nothing was at those distances as I shot everything in yards and the match was set up in meters.... so I was guesstimating all day...

My question to all of you awesome folks is what do I need to do in my app to make it match my confirmed drops.

I am the kind of shooter who is always striving for first round hits. Even when just plinking.
 
Does your ballistic program take into account the vertical wind component which is prevalent when shooting rimfire ? The vertical displacement(Magnus Effect) will vary relative to bullet shape and velocity, and strength(velocity) and value(angle) of the wind.
For right hand twist in a full value 3o/c or 9o/c wind , the bullet impact will be right and down and left and up respectively

It may also be as simple that ammunition doesn't necessarily work as predicted by a computer program. Therefore, the importance of practicing with everything in the real world.
 
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Trying to match a ballistic program to the actual performance of your ammunition may well be an impossible challenge, especially so as the distances increase beyond 100 yards.

According to the manufacturer, SK Rifle Match has an average MV of close to 1070 fps (327 m/s). In your rifle the average is 1000 fps, which shows that an ammo's MV depends on the rifle. The ES is not stated but could be over 50 fps. As dryfire observes, the predictability of rimfire ammo behaviour may not coincide easily with a ballistic program.

According to Vortex, the scope has 0.1 MRAD adjustments. Has that been confirmed by testing? Sometimes scope adjustments are not exactly what the manufacturer claims.
 
What barrel length is the rifle? And what barrel length was the ammo chonographed with?

Do you have access to chono your actual velocities?
 
Well I was there too and had the same problem...

I used a Lapua app on my phone 1180 FPS with BC of 0.114 with Eley Force which was tweaked to match my actuals from Thursday night.

Other guys in my squad were using Kestrel Wind Meter and Garmin 701 GPS both with Applied Ballistics Software.

I'm not 100 Percent sure but the winner I think used the Garmin 701 (and a crazy accurate $7000 Voodoo rifle) I watched him pound on the 1 inch gong at 88 yards four times in a row worth 5 points per hit on the KYL rack. That's confidence from the empty plastic barrel on its side in the snow. This aggressive approach won the match for him BTW, because if the 1 inch was only worth 1 point he would have came in 2nd place.

The 2nd, 4th and 11th place guys used the Kestrel

I think the 7th place guy used Garmin 701

What seems to be the key difference is real time come ups as opposed to calculated values based upon slightly different weather conditions. You need ballistic results that are based upon the weather conditions at the time of the stage, not yesterday or last week.

I confirmed my zeros on Thursday, but by Saturday things changed and I got several WTF misses as a result. The morning started out cold (like my zeroing day) and I got good hits but as it warmed up, I started shooting high and since its so hard to call the miss I did not realize until later what was wrong.

I've shot with the guys who use the Kestrel at Meaford PRS match and they did very well there too and they exclusively used come up and wind values from the device.

Having said that, they did confirm and re-confirm the output values did coincide with actuals which had been tweaked several times prior to the match.

The Garmin 701 is about $800 and the Kestrel is about $1000, my advice is to spend the money and learn how to use it.
 
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I would attribute most of the issues to weather - I have a strong feeling that 22 ammo is very affected by weather (temp).

I also have issue with Strelok - I find that it is not as accurate as AB or some of the other programs out there.
 
There is a new Kestrel 2700 coming out this spring that might be worth looking at. Starts around the 2:30 mark.

 
If you are guessing on anything you can’t expect proper results.
My $0.02 from my limited experience with Strelok:

- Scope height measurement (center of bore to center of tube)
- enable zeroing weather, that way it can take those differences into account. 22lr is easily effected by changes in weather imo, especially when we go from dry cold winters to damp hot summers.
- skip the crono and use the trajectory validation in the app. If your chrono is wrong you could be entering bad info to the app.
- hold for wind, you’ll spend more time chasing a contantly fluctuating input than making your hits.
 
This is a cheaper alternative that works with Strelok. I bought one of the blue versions, but haven't tried it yet.


 
Kane519 said:
Good advise, but the price is hard to stomach. The only other is to go old school &, as Dryfire said, collect real-world data.
Click to expand...

The problem with that is you cannot shoot all weather conditions. I'm an old school guy, but I've learned my lesson the hard way that these devices provide a competetive advantage.

Are you seriously going to calculate density altitude before shooting? You can... sure... but these devises do it automatically.

Plus they account for rotation of the earth... Coriolis... etc.

Its just a lot to figure in your head and in PRS match competition where they try to stress you out... you cant think of it all and you will find yourselves losing to guys with such devices. These devices reduce cognitive debt... preoccupied thought... uncertainty... that all affects your confidence.

If you're a bean field plinker… well that's ok... do what you can with what you have.
 
Maple57 said:
The problem with that is you cannot shoot all weather conditions. I'm an old school guy, but I've learned my lesson the hard way that these devices provide a competetive advantage.

Are you seriously going to calculate density altitude before shooting? You can... sure... but these devises do it automatically.

Plus they account for rotation of the earth... Coriolis... etc.

Its just a lot to figure in your head and in PRS match competition where they try to stress you out... you cant think of it all and you will find yourselves losing to guys with such devices. These devices reduce cognitive debt... preoccupied thought... uncertainty... that all affects your confidence.

If you're a bean field plinker… well that's ok... do what you can with what you have.
Click to expand...

That is a little bit of a stretch on how good they are...

DA can really be done in 2,500 ft blocks and your values will still be good enough. Lots of guys (older) still use drop cards.

A good shooter will use what he has, either get an impact and keep going or spot his miss and correct.
 
Well Ryan I tend to disagree based on what I've seen first hand... I was once a non-believer as well.

In the context of small bore and the relatively cheap low res glass guys are likely using... spotting misses during the match is easier said than done sometimes.

I use a Diamondback tactical scope and the resolution is nothing to impress and it makes it hard for me to spot rounds from anything but the best positions. Even from a solid bench it can be tough at distance... I used an old Leupold 24x target scope for spotting because its sharper during zeroing sessions..

Now, I've seen guys at matches who I assume take $4000 glass off their high power stuff and put it on their Tikka 22... Or maybe they just have that kind of cash to dedicate high end glass to a 22... I don't know. But I'm sure a good scope will make the difference. Perhaps I should have taken the scope off my Cadex for the match.

The match this past weekend was won by a guy from Quebec who was a hard core gamer running a Vudoo and a Garmin 701... but second place went to a 20 year old who I know for a fact never even fired the rifle he used prior to the match. He hasn't fired any rifle in 6 weeks prior to the match.... Just too cold out.

They (meaning the family who shared the rifle) relied 100 percent on data from a Kestrel... which had been calibrated to the load.

The kid just has a real easy mild mannered way about him... he stays calm... and shoots straight with good data. I know for certain there was 1/2 MOA changes (maybe more) in vertical over the course of the day.... and they accounted for it with the data from Kestrel. They didn't waist any energy thinking about it... the Kestrel said this... they did this and got a lot of hits. They all 3 finished in the top 11 out of 64 guys.

These guys are not supermen... in practice they shoot no better than I do... I shoot with them all the time.

You can believe it or not... but among ourselves we all agree the difference is the Kestrel and it has me trying to justify spending the cash to get one.
 
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Having high-end gear does not make you a gamer... Also, the Vudoo is a great rifle, I have one with a Minox ZP5 on it (so a $6,500+ 22) but for what you need to win in CRPS matches it does not make a difference. Any CZ with a good scope will have more than enough accuracy to do just as well .

I have shot and run (I was one of the MDs for the SAPRL and was the MD for CDTSA matches for 2 years) over a dozen matches. A kestrel is great but it won't take you to the podium if you don't have your skills sorted.

You can not buy points in any shooting discipline. It is hard to admit when you get out shot and say it is because the other guy has "better gear" but it is the guy pulling the trigger that wins or loses the match.

A cheap wind meter and an free app will get you 99% of the functionality of the a kestrel.
 
It looks like your app is about 4% off what your real world dope is.
I’d say just add 4% to what the app tells you and you should be pretty close to actual drop
 
You guys can all make your assumptions and draw your own conclusions.

I know what I know and I've seen what I've seen.

You want to blame my incompetence and compliment the guy who outshot me and attribute the difference purely to skill.

You want to paint me as petty and a poor looser.

I get it, I hear you and you 100% are wrong.

If the dope was good yesterday and is crap today then your shooting today is crap, its as simple as that. You can try to compensate and adjust but you are just playing catch up.

All I'm saying is the Kestrel adjusts for all that and it makes a difference. Its a small difference from your keyboard on the internet but miss a plate by 1/2 inch at 240 yards and its a miss.

I really don't give a rats butt if I win any match these days... I have no wall space for the awards I already have. And if guys out shoot me, that's great and I applaud that as much as anyone, but when the bullets are not going where you think they should be going... you have to figure out why. In the end it's the drop data... it was right on Thursday and wrong at times on Saturday....

but the Kestrel was right all day on both days.... go figure.

Guys, I've got a background in Aerospace Engineering, I'm also a software developer I do quite a bit of work with involute curve calculations and non linear regression and I do scientific research and experimental development for a living. I study data every darn day. The kestrel has more intelligence in the software that uses atmospheric sensors to compensate in real time... people are not that sensitive... people when rushed are not that smart... nobody is... people get distracted... the devise doesn't... it has one purpose and it does most of it better than anyone can, that's all I'm saying.

The wind is the wildcard, but the drops are solid.
 
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You said the same thing after you shot Meaford...

Go buy a kestrel 2500 and download AB. You may be into it for $200. Or just ask a guy with a kestrel for the DA and get AB - maybe $40.

You should be able to win after that...
 
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