Sighting in issues

[Bowhunt-R]

So I have a CVA paramount shooting powerbelt ELR and 105 grains of Blackhorn by weight. Last season I had the gun shooting great groups out to 400 yards. I recently took the gun to the range and went to verify my 200 yard 0. Just as expected my gun was still on. I shot at 300 and I shot a softball size group but I was 3” high and 8” left. At 400 I shot 6” high and 12” left. I reduced loads to 98 grain by weight and my groups are tighter, but I’m still high and left as I move further out. Why would this happen all of a sudden? My scope is level, and when I move windage my 200 yard groups are way right. Any ideas? It was not windy at all while I was shooting.

 

[45-70]

to me your bullet doesn't work or wind is getting you

 

[ENCORE50A]

Barometric pressure, temperature change, wind, propellant, different bullets or, bullets that weigh slightly different, any and all of this can change the POI.
However to be "dead on" at 200, if that's what it is, then be off 8" left at 300 could be a combination of shooter and wind. There will be some spin drift, but not 8" of it. 12" left at 400? There's two things again ... IF .... they are grouping. Shooter and wind. Ask any long range shooter about wind. What you experience at the bench could be WAY different than what is happening at 300 or 400yds.

Now, if you're shooting through one of those CVA brakes, take it off.

 

[Bowhunt-R]

I do have a brake on the gun. It was installed by arrowhead. It is their brake and I have the arrowhead breech system installed. I had it shooting great without making any changes to it between last year and this year. I’ll take it out again and try it at all ranges again.

 

[X-ring]

I do have a brake on the gun. It was installed by arrowhead. It is their brake and I have the arrowhead breech system installed. I had it shooting great without making any changes to it between last year and this year. I’ll take it out again and try it at all ranges again.

Any body that shoots longer ranges gets lots of practice using the windage knob on their scope or vernier sight. ANY wind will affect a bullet at distance. X

 

[Marky-D]

Forget the wind -- how do you get your bullets to continue RISING out to 400yds? Even a .300 Win Mag will drop 10" at 400yds with a 200yd zero...

 

[old man jim]

To get the bullet to continue rising to 400 yards, you must zero the rifle at 500 yards.

 

[Bowhunt-R]

So I went back to the range, started back from the beginning and had to readjust my turrets. I was high at all ranges beyond my 0. I think the there was more wind at the target that I thought. Once I figured out my drop I was consistent at ranges from 100-400. Not sure why I had to readjust, but I got it back to where it needs to be. I’m going out again tomorrow to shoot some more. Hopefully there won’t be any wind.

 

[Far Sighted]

So I have a CVA paramount shooting powerbelt ELR and 105 grains of Blackhorn by weight. Last season I had the gun shooting great groups out to 400 yards. I recently took the gun to the range and went to verify my 200 yard 0. Just as expected my gun was still on. I shot at 300 and I shot a softball size group but I was 3” high and 8” left. At 400 I shot 6” high and 12” left. I reduced loads to 98 grain by weight and my groups are tighter, but I’m still high and left as I move further out. Why would this happen all of a sudden? My scope is level, and when I move windage my 200 yard groups are way right. Any ideas? It was not windy at all while I was shooting.

I suggest your scope isn't aligned. Do you use a bubble level attached to your scope? That's the best way I know to minimize canting.
Until I put a level on my rifles and crossbow scopes I had lose groups and chased left and right miseries.