Sight in distance

[Mark in Mo]

I have been using a "zero in" distance of 200yrds, for my 243 and 25-06...but I'm having problems using my phone app (sterlok) I input all environmental conditions and the solution rarely works
I know it could be many different variables, just wondering what distance do you guys use for zero

Thanks

 

[deadidarren]

200

 

[Rick Richard]

200 also

 

[FearNoWind]

I also zeo at 200 - where is it that the solution "rarely works"? If you zero at 200 what does your dope sheet tell you for every 100 yard increment out to your selected effective range? What's your data input (MV, BC, etc.) Is your BC input G1 or G7?

 

[Mark in Mo]

I'm fairly certain the info I plug in is good, I keep rechecking it anyway...so it must be me lol!
Example, plug in all weather info zero rifle 200yrds

environmental conditions
alt 683
tem 82
pres 30.12

Load
bullet 117 sst
BC .390 (G1)
MV 3030

scope height 1.8

target 400yrds dial up 4.61 moa (4.5)

I shoot nice little 3 inch group but 5 inches high could this be a parallax issue...some times the group could be low...I seem to be always chasing a different MV....it is a cheap F1 chrony but have used the Validate vel feature but the next time out it calls for another vel
So I'm trying to narrow down the problem, I suspect it is me....I try to fall back to my fundamentals rifle is supported bipods in front, bag filled with corn in rear. have natural point of aim. load bipods enough before they slide forward let out breath 2/3 of the way. Trigger hand is loose. gently squeeze trigger...
Could not adjusting parallax properly cause meandering groups?

 

[Barrelnut]

If you are shooting 3" groups at 4oo yards, I doubt it's your shooting fundamentals.
Are you sure the scope is dialing correctly? Have you tried a box test on the scope?

 

[Mark in Mo]

Never tried the box test but at 100yrds moved it 10 clicks up and the group moved accordingly....moved it back down 10clicks and was right back into the group

 

[bigngreen]

I sight in every thing at 100 yards to mitigate environmental changes to my zero data but it may be high.

There are several things that could be doing it, scope tracking would be a likely culprit as would velocity but they both look the same unless you measure one with precision, miss using or not being precise enough with environmental data can lead to issues that show up from one day to the next and could a head wind or tail wind!

Shooting a tallish target at exactly 100 yards would give you a good idea of gross tracking error, you need to shoot at the bottom of the target then dial up one rev of the optic and shoot, then another rev and so on then calculate the tracking, this would work well for the ranges your looking at.

I would suggest getting Strelok Pro, it's only a few bucks but you get some valuable tools one of which is a validation tool that may help you with velocity issues once you nail down your scope tracking, it will also let you utilize a G7 BC once you need it.

 

[Bater]

What scope?

 

[Mark in Mo]

I have a I-phone 4...I don't think I can get the Sterlok pro version, mine does have velocity validation
When you say at 100yrds but high, I'm guessing that would be like 1 or 2 inches high. In my case it shows at 100 it would be 1.15 high (200yrd zero), therefore shooting at 100 impact should be 1.15 inches high
I think I will start over and use a 100yrd zero re put in all information shoot too 400 and use the trajectory validation tool
Scopes I'm using are Vortex pst 4x16 on the 25-06 and the LR 4x16 on the 243 both of which are dealing me fits...I seem to be the common denominator LOL!

 

[Barrelnut]

You could check your numbers against one of the online ballistic calculators. Berger has one. If they calculate close to the same, it's not the App. Seems like it would be the numbers or the scope.

 

[bigngreen]

Ballistics programs can be a hero or zero kind of situation, check and double check your inputs and you'll get it dialed in, then you can push out farther and deal with the challenges in the next range

 

[FearNoWind]

alt 683
tem 82
pres 30.12

bullet 117 sst
BC .390 (G1)
MV 3030

scope height 1.8

target 400yrds dial up 4.61 moa (4.5)

If you're shooting under 1moa groups at 400 yards you're problems are relatively small. A lot of bench rest shooters can't shoot that well. Our precision is excellent; it's the accuracy you need to nail down.
I prefer not to use G1 BC data for ballistics, but if that's all you have it will get you in the ball park. My calcs are close enough to yours, even when I use G7 data (.192) for your bullet. With a 200 yard zero, I get a 4.1 inch drop at 400 compared with your 4.5.
Your comment about chasing MV causes me to suspect you may not have good chrono. data and the 3030 could be at least part of the hang up; but 5 inches high when you've adjusted for a 4.5 inch drop seems a bit peculiar even with slightly adulterated MV input.
Read this:

Parallax in Rifle Scopes

and test the parallax.
Then, try these techniques (combined) in your hold.
!. Let the bipod rest firmly on the ground without loading it forward. If you're using a pad (carpet or other surface) under the bipod that's OK as long as you don't try to load the bipod.
2. Let the butt contact your shoulder (make sure you're in the pocket) with only a very slight pressure (just enough to know it's there) to create a semi free recoil. Be careful not to ride up on the scope too closely when sighting.
3. Make sure the butt bag isn't pressing more heavily on one side of the butt than the other and don't allow your left hand to interfere beyond squeezing the butt bag for elevation adjustment.
4. Press, don't squeeze, the trigger.
Are you sure you're adjusting the moa correctly?

 

[Mark in Mo]

Thanks guys...as a human I want to think I'm doing everything perfect LOl!....but I'm a realist and know that the math/science should work, the saying junk in junk out might be the culprit or it is me
My game plan is to start over with original load sight in 200yrds punch in all the specifics then test solutions same day with the same environmental conditions, taking plenty of time between groups on cardboard at 400 and 600yrds...while using the same bench same bags and record my results a little better...might be a few weeks before I get out to the farm to do this!