.257 Wby - Perplexed

[300winnie]

I took my .257 Weatherby out a couple of weeks ago while checking zero on one of my other rifles and decided to run it through the same exercise...even though I am still working on a final load.

I fired a couple of groups with the gun at 100 yards, and while not stellar groups I felt like a got the gun reasonably close to where I thought it should be to be zeroed at 300 yards or close to. I got the group to center right around the 2.5" high mark at 100 yards.

I then moved the target out to 300 yards. I fired one group out of the gun and when I got there I was pretty happy on one hand, and totally perplexed on the other.

The group is a nice triangular shape that measures right at 2.75", so I got a sub m.o.a. group that has nice shape. What is totally perplexing to me is the location of the group. You will notice in the pictures that the 100 yard group (first pic) is centered nicely on the vertical post. You will then notice in the picture of the 300 yard group (second pic) that the group is centered roughly at the same height (2.5"), but it is clear over to the left approximately 4".

Now, I know the first question is going to be about the wind...the was no, and I mean no noticeable wind. The other rifle I tested at 300 dropped right in where it should have.

A little about the gun. Weatherby Mark V Deluxe that has been bedded in a Fibermark composite. Rifle wears a Bushnell 4200 in 2.5X10x40mm set in Leupold mounts and rings. The load consists of Weatherby brass, Federal 215M primers, RL25 and 100 grain Barnes TSX bullets. The load chronographs right at 3,600 fps.

I am really confused as to why it shot this way at 300 yards. Any ideas??

 

[James Jones]

My first thought would be to your shooting position , if you squeez the gun or jerk the trigger , let it free recoil crown the scope have a poor cheek weld , whatever it could be extending your range only compounds little things that need to be fixed. Like the old saying goes
"Little things matter and long distances"

Bent barrel?
Barrels have a natural curve to them reguarless of who or how they were made , while I admit that would have to be a hell of a bend its not impossible. I one saw a Hart barreled rifle that would shoot consistant 3/8moa groups at 100 and also at 200 and 300 but they gradualy worked their way off the target to the right , this gun would group close to 1/2moa at 600yds but almost 4 min to the right. The barrel was marked for top dead center and removed , we indicated it to find out that it was curved so we just cut it back a little to freshin the chamber and throat and indicated to to where the curve was up.

 

[kfrye]

Could it be possible that scope is canted in the rings a little bit. Darrel Holland as an article on here about reticle perpendicularity. You might try cranking elevation in at 100 yards to see if the group strays to the right.

 

[barm]

Make sure you are keeping the recoil pad of the rifle in the little pocket between the top of humerus(arm) and under your clavicle(collar bone). Also, what is the shape of your rifle's stock and what kind of rear bag do you use? If the stock has a cheek piece and you have a long-eared bunny bag it could cause the rifle to shift to one side during recoil.