Weird grouping...

[Idaho Savage]

So a few days ago I shot very tight 100 yards groups in the bullseye with Remington a frame swift 200g. Today I went out with Herters 185 and shot beauty groups again.. Probably 1/3 inch. But... The groups were about 2 inches high and an inch right. Can changing ammo move placement but still maintain group Integrity.? Or did something happen to my optics?

Sent from my SCH-I605 using Tapatalk 2

 

[bh-ltr]

Most certainly changing ammo can move placement and still maintain group integrity.

 

[sib1948]

It's obvious from your post that changing ammo can change POI. You answered your own question! Go figure.

 

[JSTARSZ]

Sometimes is amazing how such a change can be so drastic. Even if you change from 175 Sierra to 175 Nosler bullets you will get a change as they are different. It is also amazing how you can get a change from two different lots of a certain bullet and that is why a lot of shooters try to buy a bulk load of the same bullet lot, same powder and same primers lots if they can. All these changes add up in the field and if you multiply out your changes in yardage it will make you miss a target.

 

[Greg Langelius *]

The recoil energy thrust force curve and bore transit time will act on the shooter so that when the bullet emerges, the bore will point to a different POI for each load.

Remember, unless the rifle is held in a rigid rest, Point of Aim is not about where the rifle alone will shoot to, but more about where we need to initiate the body/rifle system's recoil cycle so the bore ends up pointing to the Point of Impact when the bullet emerges.

There are recoil motions during the bore transit that must be accounted for in advance when aiming. This is one reason why consistent muscle tension and proper NPA are so crucial to achieving a consistent POI.

Greg

 

[Idaho Savage]

Thanks guys. Makes sense and honestly I'm happy to have found another factory round that groups well.