What Do You Make Of This?

[Bart Solo]

Over the weekend I decided to begin my preparation for deer season by working up a handload for my 92 Rossi in 45 Colt.  After loading a batch of 250 grain XTP bullets,  I took them to the range along with a box of Hornady FTX Leverevolution bullets.  My handloads shot, more or less to point of aim at 50 yards, from the bench rest.  The pointy Hornady bullets shot the most beautiful pattern I have ever seen from my levergun at that distance.  The only problem was the Hornady bullets were about 2 inches to the right of the bull.  My question is this, same gun, same sights, same day.  One type of bullet shoots more or less to the point of aim and the other shoots to the right of point of aim lights out.   I am not worried about my handloads.  I can work on them and I don't expect single hole accuracy from the XTP bullet, anyway, but what would cause the Hornady Leverevolution bullet to shoot right. 

[BBF]

 
                   Harmonics!

 
This is not a rare occurrence. It could be to the left or higher or lower with the next type/style/weight of bullets or a change in powder or the amount of the same powder.

[murphdog]

I agree with Scatterbrain.  Barrel vibrates back and forth (actually around in a circle corresponding to rifling) and the leverevolutions happen to exit the barrel while vibration has it pointing a little right.  Speed the bullet up, slow it down, change the bullet weight, etc, and that point of impact will change.  I've seen this when working up a series of handloads with gradually increasing powder charges. 
Duane

[anachronism]

Different bullets shoot to different points of impact. If you want to use them, you must adjust your sights to match.

[huntswithdogs]

Bart,
I can load three different brands of 100gr 6mm bullets in my 243, with matching powder charges, primers and brass and have them shoot to different POIs. They may be close but definitely 3 POIs. Why? Heck I ain't got no idea! All I know is I've proven it to myself time and again over the last 25 years or so. It may be harmonics or how much of the bullet is actually contacting the riflings(bearing surface). There may be one bullet that creates more or less drag while in the barrel.
What you found out is a good thing. You've got 2 loads that shoot pretty much the same. If you were to move your sites just a tad, you now have 2 loads to chose from when heading out the door. Either that or hold a little left when shooting the pointy Hornadys.

HWD

[Bart Solo]

The pointy Hornady bullets are the best I have ever seen out of my 45 Rossi, by far.  Not even close.  I guess I will just my rear sight a little to the left, or maybe hold just a little to the left.  Either way I have a round I can feel good about stalking the deep woods.   

[SHOOTALL]

Crimp , jacket thickness , FPS , Jacket hardness , trim length , recoil difference and as stated harmonics all could effect group and poi . Of course light and hold could also. then wind .

[DANNY-L]

If the load is to your liking go ahead and adjust the sights it'll be much easier to just pull up and aim rather than to adjust for the difference.

[sr sawyer]

In a 300 Weatherby I once had a POI change of  two inches up and an inch left and the only change I made was different lot numbers of factory ammo.  While they both shot 1 MOA they would not shoot to the same POI.
 
DANNY-L has the right idea to go ahead and adjust the sights.  Not only could you forget to make the field adjustment but if you are shooting 2" at 50 yards this could possibly translate to 4" at 100 yards.
 
Ken

[res45]

Every time you change a component you change the variables,even the amount of crimp or lack of one can change POI.  You can even take the same load you shot change the bullet seating depth and change the POI. 

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