Zeroing a scope with an offset mount?

[Willie D]

I couldn't bring myself to pay for diopter sights that cost twice as much as my rifle so now I'm planning to scope my K31.

My question is, are there any particulars for how should one zero a scope that is not centered over the bore?


Presently I only have access to a 100yd range. If I zero at that distance wouldn't the bullet be missing right by the width of the offset at 200yds and doubling the miss every 100yds thereafter?

Is this a real problem or am I over-worrying? Solutions besides finding a longer distance target range?

 

[Brian Pfleuger]

Presently I only have access to a 100yd range. If I zero at that distance wouldn't the bullet be missing right by the width of the offset at 200yds and doubling the miss every 100yds thereafter?

Yes, the bullet will head right by the amount of the offset for every multiple of the zero distance.

It's not a "real" problem. Real problems are like bent barrels and concrete in the muzzle. If you know the error you simply compensate, just like you would for bullet drop. It does add some complication.

However, since the left/right "zero" and the up/down "zero" need not be the same, you could just left/right zero at, like, say, 1000 yards, and you'd just be slightly left the whole way. (that would be the easy solution) For instance, if it off-set by an inch then make it 9/10 of an inch at 100 yards and you'd have a 1000 yard "zero".

 

[Jimro]

If your scope is offset to the left half an inch, simply zero the rifle to shoot half an inch to the right of point of aim. That way the offset between POA/POI is the same for ALL distances.

However, if your scope is offset and you zero at 100 yards, at 200 yards your scope should only be hitting the same amount as the offset (excluding elevation). So half inch offset zeroed at 100 means half inch POI shift at 200, 1 inch shift at 300, 1.5 inch shift at 400.

But it all depends exactly how offset your scope is, and how you want to handle zeroing. I recommend an offset zero so that you don't have to fiddle with windage and elevation when adjusting for range, but there are those that shoot quite well adjusting both.

Jimro

 

[Lashlarue]

You need a laser boresighter and a protracter.Measure the height and width distances from your bore centerline.Put your rifle in vice with the boresighter pointed at the farthest wall.Turn on the boresighter and mark a dot relative to your measurements, then zero your scope to the dot you marked on the wall. 223 is a flat shooter out to 100 yds. when you go to the range you can fine tune it, but you should be pretty close.You can buy a laser boresighter for less than $30, my Bushnell was $27 delivered.

 

[sneaky pete]

"It's just right angle geometry"

old Sneaky here. as said befor Cross hairs 1" lt. 0@100= 1"rt@200, 2"rt@ 300 etc. Oh and then don't forget about the wind. THANX--S/P

 

[Palmetto-Pride]

Just turn your rifle to where the scope is over the center of the bore, level the scope and zero like you would normaly........lol........j/k

I would do as some have said.......just measure the offset and always know that it shoots that distance either left or right of your POA from 10 yds to 1000 yds I mean whats it going to be 1.5" at the most.