100yds sub MOA 800yds a joke

[RockyMtnMT]

The SG will be higher farther out than it will be at 100 yards.
After 500 yards everything becomes difficult to repeat. I have a 30-06 that will put Remington Core locts into a sub Moa group at 400 yards. After that, I don't know where they hit!!!
So even though your getting sub groups at 400, your loads could be falling apart when you go farther.
This it a sporter weight factory barrel that is 40 years old?
So many factors go into longrange loads troubleshooting.
What exactly is your twist rate?

How does stability increase as a bullet travels down range? I have seen marginally stable bullets shoot well at short range and then start to show oblong holes at longer range.

Steve

 

[desertbull]

Do you have a level on your scope? Scope cant, wind, human error, trigger squeeze, breathing, etc.....these factors all multiply at extended ranges. Also, just because the wind is blowing a certain direction and speed where you are shooting from does not mean that twind speed and direction is the same all the way to the target 800 yards away. Brass prep, consistant seating depths and powder weights also show up much more at 800 yards and probably don't mean much at all at 100.

 

[woodnut]

Don't know if I can help, but I do have a 260 in an AR10. I am now shooting the 130 ELDs with a BC of over 500 at about 2750 to 2800fps. I have no trouble reaching 1000 yards, but the target I'm shooting is a 2 ft. circle. But I know you can push the 130s to 1000. The 6.5 Cred is a twin to the 260, BTY, and I think they are shooting the 130s.
Do you have, and I would expect you have, a scope level on it? Makes a big diff. Also, have you tried different bullets? I know a sub MOA at a hundred isn't always a sub MOA at distance. I would think, though, if you get 4" at 400, theoretically, it would be 8" at 800. That's a big margin of error and if your target isn't easily centered in the scope, it could be part of the problem. I hope you get it solved and I'd love hear what you did!

 

[LaHunter]

In reality, your issues at 800 yards are probably a combination of operator error, ammo inconsistencies, some wind, maybe some mirage impacting aiming precision, rifle, etc. A sub MOA group at 100 yards, and even 400 yards, really means very little at 800 yards. Maybe try shooting at 500, 600, 700 and evaluate groups as distance increases gradually.
Good Luck

 

[gohring3006]

How does stability increase as a bullet travels down range? I have seen marginally stable bullets shoot well at short range and then start to show oblong holes at longer range.

Steve

As the bullet velocity slows, the spin rate doesn't slow at the same rate. So slower bullet faster spin = higher SG.
Don't believe me, enter a bullet in the Hornady 4DOF calculator and watch the SG as distance increases.

 

[280remington]

I will change my load a little and try it at 500 and 600 to see how it does. I do hope most of it is operator error and not a shot out rifle. Again, thanks for all the help.

 

[gohring3006]

Here's something to consider if you're new at long range.https://forum.snipershide.com/forum...ship/6581395-mechanics-of-a-rifle-cant-teaser

 

[NEMTHunter]

What twist ratio do you have? Maybe this has been address already?

 

[RockyMtnMT]

As the bullet velocity slows, the spin rate doesn't slow at the same rate. So slower bullet faster spin = higher SG.
Don't believe me, enter a bullet in the Hornady 4DOF calculator and watch the SG as distance increases.

Very interesting. I played with it and you are correct. Something seems not right about it. The amount that it shows a bullet gaining in stability is huge. It does not give with field data. I will have to do some research. Maybe a call to them.

Steve

 

[Joefrazell]

Parallax maybe?

 

[RockyMtnMT]

I'll start another thread.

Steve

 

[Frank in the Laurels]

Even at 20X the crosshairs on that scope covers a large area at 800 yards...a little rifle can't, unforeseen wind moving in multiple directions...lots of factors involved here...trigger pull weight, bullet stability, your shooting skills and a ton more...my 68 Z-28 302 crossram is fast but against a pro stock it's a laugh..the rifle quality, the components and on and on we could go..800 yards magnifies a lot of issues and I always start with optics, borrow a 42 or 55 power and shoot it, bet your groups are much better..

 

[shooter72]

Even at 20X the crosshairs on that scope covers a large area at 800 yards...a little rifle can't, unforeseen wind moving in multiple directions...lots of factors involved here...trigger pull weight, bullet stability, your shooting skills and a ton more...my 68 Z-28 302 crossram is fast but against a pro stock it's a laugh..the rifle quality, the components and on and on we could go..800 yards magnifies a lot of issues and I always start with optics, borrow a 42 or 55 power and shoot it, bet your groups are much better..

I don't see any benefit in more power. With higher power you see less field of view with IMHO hurts a shooter see all there conditions. This isn't a controlled benchrest shoot with bench equipment. No long range field shooter uses really high power (at least the ones I know) Just look at the fact that all the Big money LONG range scopes are lower power 5-25, 4-27, etc.

 

[JTB]

If you are able to pull-off sub MOA at 400 yards I would say you shootings technique is sound. You are likely battling the wind and I agree selecting a bullet with higher BC will tighten up your groups. Light winds at 800 yards will easily cause the problems you describe. You don't need to give up on a sub MOA round at 400 as it is likely delivering the same performance at 800. Something you need to consider with the high temperature you describe is barrel cooling time/heat waves. I have found it much more difficult to maintain grouping when temperatures are high. Go out on a calm, cool morning and give it a try.