CCI450 v. Remington 7 1/2

[Evan]

When you guys that shoot much more than I do say that you need to adjust your load when changing primers, would you please explain how much you would need to change a powder weight that you have done. An example would be changing Lapua 6.5 Creedmoor SRP brass from using CC1 450 primers to Remington 71/2 primers. Say with 41.5 grs. of IMR 4350 and 147 eld bullets. 27" Pac-Nor barrel. It seems the variables are so many . Of course the velocity will change but the accuracy unless dramatic from day to day could change either way depending on conditions. I just would like to know how much of a difference in powder weights you have encountered to adjust going from 450's to 71/2 primers. Maybe sometimes no change is needed. I ask because some of you can shoot much better than I can and I respect your option. Thanks.

I find that each of my actions has a preference that repeats barrel after barrel, so I think it’s all in the ignition system. The difference between a preferred primer or not isn’t equivalent to a powder change or a seating depth change. No matter how I fuss with the loads, my Borden BR won’t shoot as consistently small with 450, 7.5, WSR, as it does with a CCI400. My BRL loves 450 and WSR.

 

[Steve Donlon]

I find that each of my actions has a preference that repeats barrel after barrel, so I think it’s all in the ignition system. The difference between a preferred primer or not isn’t equivalent to a powder change or a seating depth change. No matter how I fuss with the loads, my Borden BR won’t shoot as consistently small with 450, 7.5, WSR, as it does with a CCI400. My BRL loves 450 and WSR.

That just shows more variables with more calibers if you want the smallest groups you can achieve, it's never ending.

 

[Frankm]

Where the 7 1/2 and cci450 gave you same accuracy with same load, just curious, did you get velocities, es or any of that info in same shooting session??

 

[Steve Donlon]

Where the 7 1/2 and cci450 gave you same accuracy with same load, just curious, did you get velocities, es or any of that info in same shooting session??

No I was just trying to see if I could get the pressure down with just a different primer. I did go out yesterday and shoot 500, 800 and 100 yards and it was windy. Could not really tell. Same moa though.