Shooting past 400 yards

[peterk123]

Looking for some thoughts/ advice regarding shooting 600 meters and beyond. This was our first time out this far.

My first question: my DOPE card has been dead on all the way out to 400 meters. I've used it for 100 and 200 yards, and 300 and 400 meters. Spot on.

At 600 meters I should be 17.25 MOA. My son in law's setting is basically identical. I shoot 308 he shoots 30 06. Both of us had to dial it down to 14. Does this make any sense? Or is it just us? We are using sand bags. Guns are well supported. Prior to dialing down we were consistently over a foot too high.

Then there is the wind. I need to put ribbons out. Because it appears 5mph crosswind can push it about 18 inches. We were guessing, trying to figure out when it was blowing, when it was not. We were within a foot left to right always, but that is just unacceptable. Need to work on that.

Both of our guns are shooting 1 MOA at 100.

So fun thing we figured out about the boy's gun. We have had a hell of a time zeroing it. So the other day I grabbed the torque wrench and told him I wanted to check the action bolts. Well one wasn't even hand tight. Cranked it to spec and the gun was spot on. Lesson learned. Check those things out every couple months or after a season of banging around in the mountains.

 

[PatMcD]

I think we've talked about it before, but there is mathematical/computer/ theoretical zero,.....and then there is the REAL zero.
Your dope card got you on target and you polished it up from there. Now you have your real zero.

 

[peterk123]

Is there a way for me to mathematically back into the drop at longer distances once I have confirmed it at least at four shorter distances?

 

[Stee]

just started shooting at 400, the wind can be very humbling.. huge learning curve shooting a cross wind

 

[peterk123]

Im good out to 400M. Drop all of a sudden at 600M is not working based on the computer model. So in just a bit baffled as to why.


And ya, the breeze kicks it up a notch!

 

[PatMcD]

Is there a way for me to mathematically back into the drop at longer distances once I have confirmed it at least at four shorter distances?

You can have an educated guess, that will get you close, but don't take that long shot for "money" until you have confirmed a zero with rounds on target.

Reading wind is a whole different kettle of fish. I'll sum it up with one word: mirage.

 

[peterk123]

You can have an educated guess, that will get you close, but don't take that long shot for "money" until you have confirmed a zero with rounds on target.

Reading wind is a whole different kettle of fish. I'll sum it up with one word: mirage.

Okay. Makes sense. My son in law has an army buddy that was formally trained to shoot long distances. Time to recruit his help and kick this up a notch.

 

[PatMcD]

Okay. Makes sense. My son in law has an army buddy that was formally trained to shoot long distances. Time to recruit his help and kick this up a notch.

He can help.
I've got literally thousands of rounds downrange at 600 yards. I have a zero taped to the side of my stock, but that zero is based on those thousands of rounds. But, when I change barrels or change anything with that load, I need to start over and get a new zero. I'll be close, but probably not X-ring close. Also, as that barrel wears, the zero may change. My zero here in Maine is not my exact zero in Ohio. Etc, etc. There are a lot of variables once you get out that far, and your experience will be better than any computer ballistics program.

 

[Mountain]

Looking for some thoughts/ advice regarding shooting 600 meters and beyond. This was our first time out this far.

My first question: my DOPE card has been dead on all the way out to 400 meters. I've used it for 100 and 200 yards, and 300 and 400 meters. Spot on.

At 600 meters I should be 17.25 MOA. My son in law's setting is basically identical. I shoot 308 he shoots 30 06. Both of us had to dial it down to 14. Does this make any sense? Or is it just us? We are using sand bags. Guns are well supported. Prior to dialing down we were consistently over a foot too high.

Then there is the wind. I need to put ribbons out. Because it appears 5mph crosswind can push it about 18 inches. We were guessing, trying to figure out when it was blowing, when it was not. We were within a foot left to right always, but that is just unacceptable. Need to work on that.

Both of our guns are shooting 1 MOA at 100.

So fun thing we figured out about the boy's gun. We have had a hell of a time zeroing it. So the other day I grabbed the torque wrench and told him I wanted to check the action bolts. Well one wasn't even hand tight. Cranked it to spec and the gun was spot on. Lesson learned. Check those things out every couple months or after a season of banging around in the mountains.

What bullet and what's your muzzle velocity? If I push a 175 Nosler RDF at ~2640 fps, my 100 to 600 yard drop is ~15.3-ish MOA.

 

[peterk123]

What bullet and what's your muzzle velocity? If I push a 175 Nosler RDF at ~2640 fps, my 100 to 600 yard drop is ~15.3-ish MOA.

Nosler BT 175gr. Getting around 2750fps. 14MOA seemed to be the number that was working. Based on your info, it seems to make sense then.

 

[Mountain]

Nosler BT 175gr. Getting around 2750fps. 14MOA seemed to be the number that was working. Based on your info, it seems to make sense then.

You had a little lower BC but velocity that more than made up for that to give you that ~14 MOA drop.

First time shooting the RLD's in a match I used my Kestrel and the G7 BC value to get my 600 yard come-up and my first shot was ~1.6" low and a touch left- almost an X. Some of that was probably luck because neither me nor the rifle are ~1/2 MOA shooters. Anyway, the come-up calcs from the Kestrel were solid.