Sighting in question

[A. F Medic]

A friend of mine just bought a Savage in .223. He attached a scope and the dealer said to, "Sight the gun in at 1/2 inch low at 50 yards and you will be good out to 300."

Is that correct information? I have sighted my AR at 1 and 1/2 inches high at 100 yards and do not have any problems out to 300 yards. Or are we both getting there except by a different route?

Information

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[jmoore]

I'm suspicious of any close-in zero until verified at the actual full distance. But then again, I don't trust zeros after load changes, weather changes, shooting position changes, etc. Depends on how close is close enough for you.

[enfield303t]

So many variables here, bullet weight/coefficient, velocity, offset being some. Personally I am in agreement with jmoore and am not a fan of close-in-zero. Close in IMO is only to get the bullet on paper, heck many times I don't do that, just put out a clay pigeon at 300 on a high dirt burm and have a spotter call adjustments.

I am not sure what ammo would be used to get a 1/2" low at 50 and dead on at 300? Using the ballistic calc. I posted below I can't figure out what load/bullet he would use to get those results, mind you it does use a offset of 1.5 inches.


Here is a pretty decent ballistic calculator to use.

Ballistic Calculator GunData.org

[A. F Medic]

Thanks for the calculator. My SWAG is that the bullet will drop 13 inches at 300 yards. Not counting what the wind will do to such a tiny bullet.
I will pass the information on and stress with him the importance of seeing where the bullet will hit at 100 yards! Problem is that he does not take a 2nd opinon well. Thanks to all!

[Patrick Chadwick]

I usually shoot at 100 meters, but participate in competitions shot at 300m, without an opportunity to properly sight in the rifle beforehand. For the modern milsurps with iron sights, a pragmatic setting of 5" above dead center at 100 (8" black, 6 o'clock hold) is good enough to get you in the black at 300. Then you have to adjust the height setting.

Scoped rifles are different, because of the considerably higher sight line, and POA = POI, which means that the bullet rises substantially at 50 meters, and somewhat less at 100, depending on the exterior ballistics, but a look at the Sierra trajectory tables will convince you that it is mighty difficult to have the same setting at 300. And a 13" drop of POI below POA would be unacceptable for 300m target shooting with iron sights, let alone scoped target shooting. To even get into the spread of plus/minus 2.5" given by Sierra for a "point blank" range up to 300 would require a very high muzzle velocity out of a rifle with high scope mounts.

[Youngblood]

I very rarely use scopes although, due to my presbyopia, I should probably always use scopes.

That said, when shooting over Irons I always do an initial sight-in at ~25yds so that it is more a test of the rifle's consistency than my eyesight ... but ... I never trust the resulting setting until I test it at the longer range(s).

FWIW

[jmoore]

and the dealer said

Your friend believes anything the dealer tells him aside from the final price and that he's allowed to take it home? Generally not a good plan, although there are exceptions! There's dealers I like and have dealt with for years who almost certainly haven't been to a range in all that time...