Point of Impact change at longer distances

Brambles

Brambles

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Just something to run by the other gunnutz.

My Sendero SF 300 ultra mag when sighted in at 100 meters it is about 4 inches Right at 300 meters.

The scope is a Bushnell Elite 4200 2.5-10x40, the base is a one piece leupold with dovetail front ring and windage adjustable rear.

My only guess is maybe my scope isn't running perfectly paralell to the bore of the rifle!

Any suggestions.

Also if you guys agree that it is the rear windage that may be misaligned, do you figure there is enough movement in front dovetail that if I go and adjust the rear screws that the front will move with it, or do I have to take the scope out and manually twist the dovetail?

Thanks

Brambles
 
Talkin' out my a$$ here, but I'd try a different load before attributing it to the gun. My inexperienced notion is that the projectile may be "side-winding" as a result of a mismatch between bullet weight and rate of twist.

I await the guffaws of the more seasoned.
 
Scope alignment could be one thing...

Like you suggested it might not be parallel to the barrel, or your cross hairs are ever so slighly tilted. Not noticable at 100 but out further it would make a difference.

Another thing that I noticed... (although a different calibre)... was past 300 yards the wind became more of a factor. I was fine at 100 and 200 and then at 300 we started to notice a big change with my .243 in even the slightest breeze. We have burms on our range and we thought the wind might be swirling off each burm and creating problems.

Just a few thoughts... but it might be as simple as the scope being tilted just a little bit.
 
casterpollox said:
Another thing that I noticed... (although a different calibre)... was past 300 yards the wind became more of a factor. I was fine at 100 and 200 and then at 300 we started to notice a big change with my .243 in even the slightest breeze. We have burms on our range and we thought the wind might be swirling off each burm and creating problems.
Click to expand...

I'm shooting 180 gr noslers, I have shot that same distance at the range with other rifles and my buddies as well and sure you can see some wind affect but not nearly as predictable and consitant as with the Sendero.

Our range has burms too and I always wondered if they cause distortion or weird wind currents. I know there are shooters at our range ( my father included) that swear since the burms were installed the shooting conditions have changed for the worse.
 
poi shift

Brambles said:
Just something to run by the other gunnutz.

My Sendero SF 300 ultra mag when sighted in at 100 meters it is about 4 inches Right at 300 meters.

The scope is a Bushnell Elite 4200 2.5-10x40, the base is a one piece leupold with dovetail front ring and windage adjustable rear.

My only guess is maybe my scope isn't running perfectly paralell to the bore of the rifle!

Any suggestions.

Also if you guys agree that it is the rear windage that may be misaligned, do you figure there is enough movement in front dovetail that if I go and adjust the rear screws that the front will move with it, or do I have to take the scope out and manually twist the dovetail?

Thanks

Brambles
Click to expand...

Does the poi shift after you click for elevation ? If so your vertical crosshair is not straight up and down . The scope is twisted to the right. Bubble level and plumb bob time.Collaminators dont work - no bubble level in em.
 
I've had weird stuff happen...

100- bang on

200- 1" tot he right

300- 1" tot he left

400- bang on...

Voodoo...:D

Good enough to killa deer, but maybe try asking int he precision forum. Maybe soemthign isn't square.:)
 
I just had a friend in a machine shop make up 2 pcs of 1in round stock and point one end of both. A friend had a set of these a while ago and they work real well when mounted in the rings. If the points meet the rings are good. Cheap tool but nice to have. Could probably use hardwood too. 3-4in long and points at about 90degree works well. That way you can check yourself any time there is a problem and it gets that out of the way. My $0.02
 
Its been a while since I shot this gun, I've been using my custom 280 and at the same 300 yard target its bang on for windage.

My numbers were off a little Now that I think about it the POI is more like 6 inches, I ended up sighting the sendero in 1" to the left to bring it to 3" right at 300 yards. Kinda split the difference.

I'm convinced it isn't all wind, and it isn't all me. Still shoots good groups but its just to the Right 6"
 
Crank on the elevation screws. Usse a large target paper, and as u turn up the scope, the shot string should be vertical. If it rises left or right, the scope is twisted. Assuming your rifle is held the same, every time.
 
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