It's a question often asked; do primers make that much difference in your loads. I took my 338-06 to the range last week with my current favorite load: 210grNP over 63gr H4350, Norma brass & 5 diff. primers. I used F210, F210M, CCI200, RP9 1/2 & CCIBR2. All vel. were withing 25fps of each other, 2730fps+/-. The most accurate load by quite a bit was the CCIBR2 @ 3/4" (I get the same groups every time I use this laod) w/ the F210M close behind, right at 1". The other loads were bewteen 1 1/4" & 1 1/2". The loan exception was the CCI200, 3" group, ouch. It could have been me but I doubt it, have to run that one again just to see.
So it does pay to experiment w/ primers. I did the same thing w/ my 260ai & the F210M runs the best w/ the RP9 1/2 right behind.

YES THEY DO !. As DO POWDERS and CASE PREP.

It all leads to a single hole group ( of said calibers dia. maybe some day .

I've yet to experience it myself . Come close but no cigar as yet .

Shoot Straight know Your Target . ...

quote:

Originally posted by fredj338:
....The most accurate load by quite a bit was the CCIBR2....

Last winter at the range, I tried those primers in a cold day (0° C), calibers were 300 WM and 270 WSM. I had several hangfires with both rifles. I will not use them on hunting rounds any more.