I'd change the front sight myself, if possible.

Reducing the height of the rear sight's flat surface is another option, but I'd probably attempt loading changes, different powder.

You are holding the forend with your left hand as you shoot off a rest, aren't you? Letting the rifle bounce by resting the forend on the bags, can give false elevation to the impact. I now hold all kicking rifles as if I was shooting offhand, and rest the back of that forend hand, on the bags. That way, no matter what position I shoot from, the impact is identical.

As 500Nitro posted above, change one thing at a time with testing in between.

12" high at 100, is too high for a rifle that will be used mostly at 100yards or less. Having to always figure "Now, lets see, how much do I have to hold low" is a recipe for disaster when a fast shot must be taken - bear, moose or deer.

To be used as a serious hunting rifle, the rifle must shoot to the sights.

"Holding 6 o'clock" is fine for paper target shooting where the bullet impact is carefully adjusted for that hold on a pardticular sized bull- as with ISU or other round bullseye handgun shooting.

In my opinion, a 6 o'clock hold is less than useless for game - holding 6 o'clock on a moose, elk, black bear, grizzly, brown bear or sitka deer, ie: animals with different height's from the chest's bottom to the boiler room - too much thinking - exactly how far is it? Is it now 15" high, because I'm now 'about' 130yards instead of 100yards?
THIS is why 12" high at 100yards is no good and change must be made somewhere.

I used a BC of .230. It's possible the Woodleigh has a Bc of over .300, thus, the actual height the bullet obtains, will be greater yet.

Ballistic Coeff: 0.230
Bullet Weight: 250
Velocity: 2350
Target Distance: 345
Scope Height: 1.000
Temperature: 70
Altitude: 500

Ballistic Data
~~~~~~~~~~~~~~~
Range Elevation Velocity Energy ETA Drop Max Y 10mph Wind Deflect
0 yds -1.00 in 2350 fps 3065 fpe
25 yds 2.93 in 2263 fps 2843 fpe
50 yds 6.42 in 2178 fps 2634 fpe
75 yds 9.46 in 2095 fps 2437 fpe
100 yds 12.02 in 2014 fps 2251 fpe
125 yds 14.05 in 1934 fps 2076 fpe
150 yds 15.50 in 1856 fps 1913 fpe
175 yds 16.29 in 1781 fps 1761 fpe
200 yds 16.36 in 1709 fps 1621 fpe
225 yds 15.69 in 1639 fps 1490 fpe
250 yds 14.25 in 1570 fps 1369 fpe
275 yds 12.02 in 1504 fps 1255 fpe
300 yds 8.73 in 1441 fps 1153 fpe
325 yds 4.35 in 1382 fps 1061 fpe
350 yds -1.21 in 1327 fps 978 fpe