30-30 rear sight adjustment question

[Bullseye]

OK, My Model 94 30-30 Winchester is shooting about 7-9 inches to the left at 50 yds.
Using the FORS rule ( Front Opposite Rear Same ) I wonder just how much adjustment to rear site movement I should expect to get on zero.
Since my bullets are hitting to the left, I have to move my rear sight to the right since that is where I want it to go, correct?

I figure, it won't be a whole lot, given the distance between the front site and rear and 50 yds is a ways off for open sights.

I am sure somebody has had to do this a time or two with iron sites. Thanks

 

[Bart B.]

Yes, move the rear sight to the right to move bullet impact to the right.

Divide the distance between the front and rear sight by 3600; the answer is how much to move the rear sight to change bullet impact 1 MOA or 1/2 inch at 50 yards.

If the sights are 15 inches apart (my guess for a Win 94's 20" barrel with rear sight on the barrel), 15/3600=.0042", the change on the rear sight to move the bullet impact 1/2 inch (1 MOA) at 50 yards. To move impact 8 inches at 50 yards, its .0042" times 16 equals .0667" or about 1/15th inch.

Use the 1/16th" marks on a ruler; that's close enough. Reshoot for zero confirmation.

Another way is to divide the change distance of 8 inches by target range of 1800 inches (50 yards times 36 to get inches) to get .0044, then multiply that times the sight radius of 15 inches to get .067" or about 1/15th inch. 44/10,000ths of 50 yards is 16 MOA on the range as is 44/10,000ths is 16 MOA on the sight radius of 15 inches.

 

[Bullseye]

Awesome response Bart. Will do and thanks!

 

[Bullseye]

I made a pencil mark atop the barrel just about .050+ thick with a starting point on the left side and used a brass punch and two good taps put it in line with the right side of the pencil mark. I got to thinking that maybe 8 inches was too far off and it might be a bit closer to 5 inches.
I'll follow up on this. Here's a pic.