How Much Off Target?

[G26ster]

I know there's a formula for measuring horizontal distance at a known range, but I forgot the formula from my forward observer days long long ago.

Hypothetical:

A shooter has his firearm zero'd at POA (target center dot). With his sights lined up at POA, he moves the barrel 1/8" right or left on trigger pull. How much off the center dot would the round be at 7 yards (252")? Any know how to calculate?

[hovercat]

Is the pivot point at the nose of the bullet?
What is the distance from there to the muzzle?

[hovercat]

Assuming yes and 4 inches, the bullet would move 3 one eigth per foot, x7. 21/8 or 2 5/8 inches.
This ignores that the bullet is actually traveling in a spiral as it leaves the barrel.
.

[SlowJohnny]

I got that your shot would be off 7.88" which considers that you have a 4" barrel and that your barrel pulled 0.125" (or 1.79 degrees).

[G26ster]

Thanks guys.

Hovercat: 3 one eigth per foot x 21 feet = 63/8 or just about 8 inches - no?

[C-dub]

What language are y'all talking?

[RossA]

I stopped doing math word questions when I got out of high school.
Even then I mostly failed them.

[hovercat]

Thanks guys.

Hovercat: 3 one eigth per foot x 21 feet = 63/8 or just about 8 inches - no?

My bad, mixed up feet and yards. I feel foolish, glad I did not do that at work on the construction site. Yes, about 8".