Rifle Scopes How to zero a scope at a distance other than the distance you are shooting from

[jhr1986]

Hopefully that thread title wasn't too confusing. My preferred method of zeroing a scope is to boresight at 25 yds, shoot 1 round at 100 yards, place the reticle at the point of aim and then using the turrets, move the reticle to the point of impact for a 100 yard zero.

Now, lets say you have to establish a 100 yard zero on a 15 yard range. So far my method under these circumstances is to use a ballistic calculator to show me where the bullet would impact at 15 yards (usually an inch or so low) in order to be zeroed at 100 yards. After firing one round I adjust the turrets by the appropriate number of clicks - using a scope with 1/4 moa clicks, each click should be equal to .0392625" at 15 yards (1.047/4 = .26175; .26175/(100/15) = .0392625). Is there an easier way of doing this similar to the method in the opening sentence above?

How about if I need to zero the rifle to impact 3" high at 100 yards and I only have a 15 yard range to shoot on? Should I play around with the numbers until I find a zero range that corresponds to a bullet impact 3" high at 100 yds or is there a better way.

I know the easy answer is "go shoot on a 100 yard range", but that option is not available for this discussion.

 

[deadnbrkn84]

 

[jhr1986]

Fantastically informative post. Funny pic though.

 

[gebhardt02]

If you are wanting to zero at 100 yards but can only shoot at 15 or 25 yards, your zero is going to be off a bit. That distance is just too close and a tiny amount of error at the 15 or 25 yards is going to lead to bigger error at 100 and beyond. You can get close I'd imagine, but still need to fine tune your zero at the distance you require. Don't use the 15 or 25 yard zero and expect to get hits at LR.

Geb

 

[Beiruty]

Your logic is correct.

 

[SomeOtherGuy]

Yes, it works like you posted. I have done this a number of times using a 50 yard range to zero a rifle for 200 yard competition. I've been pleasantly surprised at how well it has worked.

The big thing in my experience is to make a reasonable estimate of your true muzzle velocity, assuming you can't use a chrono at your short range. Unless you have a high quality, tight 24" or longer barrel, the factory spec velocities are higher than you will be getting. This is a guessing game.

 

[jhr1986]

Thanks guys; this isn't for precision shooting - I'm sighting in hunting rifles for customers and only have a 15 yd indoor range at work. Obviously I'd prefer to do it the right way but they aren't looking for the ultimate in precision, just want to make "hunting accurate" shots. Why anyone brings a scope in for someone else to mount or sight in is still a mystery to me but I do what the customer asks...

 

[roggom]

As mentioned the amount of error at 15 is too great. Remember at 50Y 1 moa ~ 1/2" T 25Y ~ 1/4" at 15Y ~1/6.66

Zeroing at 50 is acceptable as the amount of error is similar of that between 100Y and 200Y. So at 50Y if you are 1" off you will be 2" off at 100, at 100 if you are 1" off you will be 2" off at 200. 1" off at 15 will equal a bit over 6 1/2" off at 100, that is the same amount of error as shooting to 667Y.

but to answer your question, try to group your shots 1/2" below the zero and it should put you 3" high at 100, but who knows where it will hit.

Edit:

If your shop is being paid to boresight the rifle, that will be fine, but if you are to sight in the scope proper and being paid, it is only prudent to take the rifle to a 100Y range.

 

[Deadshot2]

Thanks guys; this isn't for precision shooting - I'm sighting in hunting rifles for customers and only have a 15 yd indoor range at work. Obviously I'd prefer to do it the right way but they aren't looking for the ultimate in precision, just want to make "hunting accurate" shots. Why anyone brings a scope in for someone else to mount or sight in is still a mystery to me but I do what the customer asks...

Like others have said, it won't be real accurate due to all the variables but at least you'll get them "on paper".

When it comes to bore sighting, I use a target about 100 yards away and do the old school "look down the bore" and then set the crosshairs. Never fails to get me within a couple inches for that first shot at the range. If your customers want to have you do a REAL sight in, just add time at the regular shop rate to go to the range and do it for them. For those that "bite" you'll make some good money and have a nice shooting session. BTW, the customer pays for the ammo too

This actually sounds like a business opportunity for a retired guy.

 

[RFutch]

Thanks guys; this isn't for precision shooting - I'm sighting in hunting rifles for customers and only have a 15 yd indoor range at work. Obviously I'd prefer to do it the right way but they aren't looking for the ultimate in precision, just want to make "hunting accurate" shots. Why anyone brings a scope in for someone else to mount or sight in is still a mystery to me but I do what the customer asks...

Why bubba refuses to shoot his guns unless a deer is standing in front of it I will never understand...

 

[jhr1986]

Why bubba refuses to shoot his guns unless a deer is standing in front of it I will never understand...

I'm with you on this, but those of us on this forum are (generally speaking) shooters first and hunters second or third. The type of guys that knowingly bring a rifle to a 15 yd range to have it zeroed are not shooters, they're the once a year hunters. I agree with everyone here and would prefer to zero these rifles at 100 yards. I'll float that idea by the boss man, but I really doubt he'd let me take a handful customer rifles off premises. And frankly I don't blame him, too much liability for him and probably not enough benefit.

 

[Deadshot2]

Why bubba refuses to shoot his guns unless a deer is standing in front of it I will never understand...

That's one of the reason's he's called a "bubba".

 

[raider1v1]

if this was the only option, id chronograph some rounds and use a program like shooter to see what a 100yd zero would give me at 15yds. thats really the only way to "work backwards" to what the elevation will be that close.

another thing is that hunting shots id say are more important to have correct vs target. if that one shot goes low/wide/whatever you may not get a second.

 

[Deleted member 10043]

15 yards? One inch high for a Bubba's 200 yard hunter zero. This will at least get him to hit something. I've seen Bubba zeroing before deer season at 100 yards. He was all over the place. First shot was off the hood of his pickup. Didn't compensate for scope height and sent a bullet through the hood into the engine compartment. Personally, I think it is reckless and would only end up with Bubba chasing that deer for a long time and hitting it several times along the way including one to the lower jaw. True story. Bubba is also a member of the village volunteer fire dept. I've seen him set his arm on fire pumping gas from getting in and out of truck while the pump was running. Went to touch the pump handle and baroomph. Bubba was waving that burning shirt sleeve back and forth while with the other hand he was putting the gas cap back on, which was also on fire. Fucking hilarious. Bubba is still hunting every year and still a fire fighter.

 

[Deadshot2]

15 yards? One inch high for a Bubba's 200 yard hunter zero. This will at least get him to hit something. I've seen Bubba zeroing before deer season at 100 yards. He was all over the place. First shot was off the hood of his pickup. Didn't compensate for scope height and sent a bullet through the hood into the engine compartment. Personally, I think it is reckless and would only end up with Bubba chasing that deer for a long time and hitting it several times along the way including one to the lower jaw. True story. Bubba is also a member of the village volunteer fire dept. I've seen him set his arm on fire pumping gas from getting in and out of truck while the pump was running. Went to touch the pump handle and baroomph. Bubba was waving that burning shirt sleeve back and forth while with the other hand he was putting the gas cap back on, which was also on fire. Fucking hilarious. Bubba is still hunting every year and still a fire fighter.

And what's really aggravating is that "Bubba", and all others like him, often have a dozen kids that will end up growing up just like Dad.

Why is it that those with higher IQ's usually have nice small families of one or two yet the "Bubba's" seem to multiply exponentially.

 

[Deadshot2]

15 yards? One inch high for a Bubba's 200 yard hunter zero. This will at least get him to hit something. I've seen Bubba zeroing before deer season at 100 yards. He was all over the place. First shot was off the hood of his pickup. Didn't compensate for scope height and sent a bullet through the hood into the engine compartment. Personally, I think it is reckless and would only end up with Bubba chasing that deer for a long time and hitting it several times along the way including one to the lower jaw. True story. Bubba is also a member of the village volunteer fire dept. I've seen him set his arm on fire pumping gas from getting in and out of truck while the pump was running. Went to touch the pump handle and baroomph. Bubba was waving that burning shirt sleeve back and forth while with the other hand he was putting the gas cap back on, which was also on fire. Fucking hilarious. Bubba is still hunting every year and still a fire fighter.

And what's really aggravating is that "Bubba", and all others like him, often have a dozen kids that will end up growing up just like Dad.

Why is it that those with higher IQ's usually have nice small families of one or two yet the "Bubba's" seem to multiply exponentially.


To be fair, every once in a while one of "Bubba's kids" actually breaks free of that culture. Who knows, maybe someone slipped in and added some different DNA to the mix while Bubba was off hunting.