Sighting in question

[bill c68]

I want to sight in my new Tikka T3 for use with multiple choices of ammo.
I am still somewhat new to centerfire rifles, so bear with me.
I sighted the rifle in a 150yds using 45gr JHP Winchester "whitebox" ammo. Got an 1.25" group at 150, not too bad. Then I switched to 55 gr Super X, thinking the only thing that should change is elevation... WELL I was right on for elevatin but I was shooting 2.5" to the right, I was surpirsed at the result.

Is this normal?
I am going to sight in the rifle again using Winchester supreme 40gr Ballistic Silvertip, this ammo is quite expensive so i didn't want to screw around with a whole box trying to zero it.

thanks

 

[dan belisle]

Yes it's normal. Different ammo usually shoots to a different point of aim. - dan

 

[Why not?]

Not only is it normal, but it can be quite surprising some times. One commomn observation is that heavier bullets at lower velocities often shoot higher than lighter ones.

You must check for each different load, and make the necessary adjustments. Sometimes you get lucky and different loads will shoot almost to the same poi, but it's not the norm.

Ted

 

[maynard]

What caliber are you shooting? 22-250 or .223. If you are shooting .223 you have a fast enough twist for heavier bullets, 69 gr to maybe 80 gr.
However, Tikka, like other firearm manufacturers dropped the ball when putting the slow twist barrels on the .22-250 when they already have 1:9 twist for .223.

 

[bill c68]

22-250.
I won't be shooting the heaveier bullets anyway.