Rifle sight in

[GMBoy]

I am pretty sure Bill in Utah will have the answer

Anyhow -

I've got a new scope that I'd like to sight in. Problem is, I cannot get to a decent range with a 100 or more yard facility for a few months. I was thinking of just going to the indoor 50-75ft range and sighting in for now.

Question - Is this ok to do or just a waste of time. Is there a "formula" or something I can do like sighting in a little high that it may be on target at 100 yards?

I'm thinking there is no way to short cut a decent long range sight in.

 

[Big_Kat]

It depends on the caliber and weight of the bullet on how high to sight in at 50 yds. Your basically sighting in at 50 yrds to get on paper at 100yrds+. I'd say 3-5 inches high at 50 would place you at least on the paper at 100yds. Hopefully somebody else could chime with a little more experience.

 

[Tegger]

Originally Posted By: GMBoy
I am pretty sure Bill in Utah will have the answer

Anyhow -

I've got a new scope that I'd like to sight in. Problem is, I cannot get to a decent range with a 100 or more yard facility for a few months. I was thinking of just going to the indoor 50-75ft range and sighting in for now.

Question - Is this ok to do or just a waste of time. Is there a "formula" or something I can do like sighting in a little high that it may be on target at 100 yards?

I'm thinking there is no way to short cut a decent long range sight in.

I'm guessing this is a centerfire rifle. What cartridge?

You're looking for a "ballistics table". Like the ones on this page:
http://www.hornady.com/ballistics-resource/external
You need to do a bit of arithmetic, of course. If arithmetic isn't your thing, just sight-in for an inch LOW at 50, which should be reasonably close to zero at 100. A centerfire rifle cartridge will still be rising at 50, which is why you need to print low on the target at 50.

 

[GMBoy]

This would be for a .223 Bushmaster AR. I appreciate the ballistics table, good to know.

 

[Bill in Utah]

Go ahead and sight it in at 50-75 ft. Then when you get to a 100 yard range you'll just have to deal with elevation mostly. (or hold high since there will be a little more drop at 100 yards than 75 feet)

Its the same as what you would do with those laser bore sighter rigs that some people use.

Good choice on the AR! Very good weapon...

Take care, Bill

PS: Make sure the range will allow .223 being shot at 75 feet. I don't do indoor ranges (I've been to a few and like to stay away)

 

[Durango]

GMBoy,

Look up AR15.com and search the forum for someone who can give you a balistics table OR get a target the Army uses to sight in their M4's at 25 yards. Some gun shops sells them.

Durango

 

[GMBoy]

Originally Posted By: Bill in Utah
Go ahead and sight it in at 50-75 ft. Then when you get to a 100 yard range you'll just have to deal with elevation mostly. (or hold high since there will be a little more drop at 100 yards than 75 feet)

Its the same as what you would do with those laser bore sighter rigs that some people use.

Good choice on the AR! Very good weapon...

Take care, Bill

PS: Make sure the range will allow .223 being shot at 75 feet. I don't do indoor ranges (I've been to a few and like to stay away)


Thanks, Bill. I do have one of those bore sight kits and have sighted in with it to get "close" so hopefully once at the indoor range I will be close enough to just need a few shots to fine tune. I also don't care for indoor ranges but in today's anti-gun culture a lot of good outdoor ranges have vanished. Thanks for the complements, I do like the rifle but since I bought it way back when the Clinton ban was in effect is doesn't look as good w/o some the "assault rifle" cosmetics

I wish I had the extra cash to buy another one today that atleast looks tough. I like the SMith and Wesson M&P and of course the Colt.


DURANGO - Thanks as well - I forgot all about AR15.com!

 

[Shannow]

GMBoy,
tegger's correct.

Your sight are well above the bore centreline, and you want them to cross at 100 yards.

If you sight it in at zero at 75 feet, you will be shooting fairly high over the point of sight at 100 yards.

Bill's right if the sight is mounted on the bore centreline.

 

[Mr_Joe]

I'd start with 1" low at 25 yards.

 

[2cool]

From my long-ago days as a Marksmanship Instructor (USAR), an M-16A1 with M193 ball ammo has a parabolic flight path that crosses the line of sight at 75 and 250 meters. As others have said, on a 50-yard range, adjust your sights until you're hitting 1-2 inches below your point of aim. You will be plenty close to point of aim at 100 yds.

 

[GMBoy]

Originally Posted By: 2cool
From my long-ago days as a Marksmanship Instructor (USAR), an M-16A1 with M193 ball ammo has a parabolic flight path that crosses the line of sight at 75 and 250 meters. As others have said, on a 50-yard range, adjust your sights until you're hitting 1-2 inches below your point of aim. You will be plenty close to point of aim at 100 yds.


Wow, a Marksmanship Instructor! I am impressed and will follow that advice for sure!

Thanks to everyone who responded - such a great group of guys.

 

[2cool]

I do mean to brag. When I was a Marksmanship Instructor, if a trainee couldn't get their rifle to zero; I'd shoot it. If I couldn't get it zeroed in 9 shots, it went to the armorer to be gauged. If the rifle gauged OK, it would reflect badly on me. In my day, I was good. Only had one rifle I sent come back OK in three years. Problem rifles weren't rare. At that time, the training schedule called for 780 rounds of ammunition each Basic Combat Training cycle, in addition to the beating they took from being handled.