6.5 Nosler Bullets

[Scholly]

Ran into an odd issue: Built up a 6.5 Rem Mag (Rem 600 action - 26" Shaw Heavy sport 1-9 twist). I completed the Shaw break in and started working up loads - I found the Nosler CC 123 groups well with 55.0 grn of 4350 running at 3270 FPS (20 FPS variation on my crony). I am seating the bullets just off the lans (probably .005). I am getting 5 shot groups at 300 just under 2" with this set up

Now the funny part - I want a good "game load" here as well - I picked up some Nosler 125 Partitions and replicated the load - I went out figuring I would be a bit low (BC on the CC is .51 and BC on the Partions is .449). Yep, 2" low and 3" to the right?!? and the group was over 4" ?!?

On a side note - I replicated the result shooting a 10 shot series alternating between loads for each shot (Even shots where CC and Odd shots where Partitions) ... the CCs stayed under 2" and the Partions kept hitting to the right and over 4"

So - should I expect 4" groups at 300 yards with Nosler Partitions? Has anyone ran into an issue where some bullets types just group to the right or left like this?

 

[Thauglor]

Maybe the partitions just don't like the same load as the CC. You might have to play with the load to get it as accurate.

 

[MagnumManiac]

Assuming that a particular load works for more than one bullet is futile, as you have experienced. Also, it is barrel harmonics that determine where POI is, not the BC of a bullet. If a bullet exits the barrel at the top of it's oscillation, it will land high, if it's high and right, then it is exiting at that point.
This is why we work up shooting groups, then choose the most accurate load and then 'tune' that load by seating closer to, or further away, from the LANDS.
Tuning a load is getting barrel time right so that all bullets exit at a point in the oscillation where the barrel is motionless, or very near to motionless, in the same point time after time.
I would try working up shooting 3 shot groups first, just to determine an accuracy node.

Cheers.

 

[Scholly]

Assuming that a particular load works for more than one bullet is futile, as you have experienced. Also, it is barrel harmonics that determine where POI is, not the BC of a bullet. If a bullet exits the barrel at the top of it's oscillation, it will land high, if it's high and right, then it is exiting at that point.
This is why we work up shooting groups, then choose the most accurate load and then 'tune' that load by seating closer to, or further away, from the LANDS.
Tuning a load is getting barrel time right so that all bullets exit at a point in the oscillation where the barrel is motionless, or very near to motionless, in the same point time after time.
I would try working up shooting 3 shot groups first, just to determine an accuracy node.

Cheers.

Makes sense (tuning for barrel oscillation) - I appreciate the feedback!

 

[Preacher]

Always has been hard to get the partitions to be super accurate in anything I've shot...