I'm going on a hunting trip in a month to TX to shoot Varmints.  My best friend and I went to the range yesterday to site in our rifles that we are taking.  I'm taking my new AR-15 from Eagle Arms.  I have a Nikon 5.5X16.5 scope mounted on it.  My best friend is taking a reminton Model 700 .223 with virtually the same scope.  Here comes the question....

We both sighted out respective rifles in a 100 yards.  They are both dead on and very accurate at that range.  We both starting shooting at a target about 25-30 yards out and I was  shooting 2 inches low with every shot while he was hitting the bullseye everytime.  Basically, his gun is flat from 25 yards to 100 yards.  Mine is low at 25 yards 2 inches and is perfect at 100.  

Obviously my question is why?  He has a standard long barrel for a rifle and I have a regular stock barrel for mine.  My assumption is going to be that it has something to do with the twist rate of the barrel but I'm  not sure.  Any help would be greatly appreciated.  

AR15223rookie

My guess is the scopes are different heights over the bore.  That affects the near zero even if the far zeroes are the same.  So long as yours is consistent you should be good to go.

That, and muzzle velocities differences.

Could also be different bullets.

Don't worry about it,  get the dope for your rifle, and enjoy your trip.

TXL

The difference is the Height Over Bore of the optics.  Your optic is mounted higher (it has to due to the straight line of the stock).

Zero your rifle at 50y and your bullet will be within 2" of the point of aim from 8M to 220M or so.

His optic is closer to the bore so it trajectory seems flatter- but if you started shooting beyond 100y you'll find his round starts dropping faster.

Zero at 50 and you'll be good to go.

This is all such common sense.  How come I didn't think of the height over the barrel.  Thanks for the help from everyone!!!!  It's greatly appreciated.  

AR15223rookie