Has anybody systemically examined the accuracy of various powder + primer combinations, specifically for any of the following powders:

-RL19
-Viht N550
-H4350
-IMR4350
-RL15

In the Dec 2008 issue of Handloader Magazine, one of the authors featured states that different powders will have definite primer preferences. For example, the most accurate primer for Varget was CCI 250 primers (in a .308). He also suggested that when developing accuracy loads, one should start with first finding the best primer for the powder selected.

I am hoping to find the most accurate load for my .300 WSM using the above-listed powders to start of with. So my first step is to find best primer(s) for each powder.

I have never seen primers effect the accuracy of a load used in a hunting rifle.

With the exception of the Viht powder, which I've never used, I've shot all of the others. And, they all shoot very well with Federal 210M primers. I've not had a need to try other primers as all of my rifles shoot well with Fed's.
The only combination of powder and primers where Federal Primers did not perform was with H-4895 in a 223 and 222 Rem Magnum. Winchester primers were the best in those loadings, not Federal 205M's.
Go straight to Federal 210, or 210M's and work from there.

Reloading for accuracy is hard enough when you only chase the real ghosts and goblins. Don't want to start chasing the imagined ones. JMO, Dutch.

Bearclan, if you can get some, try the Magpro powder in your WSM. Currently am getting less than 1/2 in groups out of a BAR. Using CCI Magnum primers.

Bearclan, my 300 WSM shoots almost identical groups using H4350 and CCI250's or Fed215's.

I looked at it many years ago, but to generate the most certain uniformity I could extract by eliminating rifle and shooter variance, I used a 30 pound open class bench rifle in .308. I found what bench rest shooters already knew, that primers both influence accuracy and sighting.

JW

I've tried different primers over the years. They rarely affect accuracy with a few exceptions.
I've found that the mild primers, like the CCI's, sometimes don't consistantly ignite some ball powders. Federal and Winchesters do well with all types of powder, so I prefer them.
I've found that in some cases, when loading at 70% or less loading density, magnum primers help. My .25-20 is like that, especially with ball powders. Reduced loads in rounds like the .280 and the 30'06 are like that.
Primers are one of the last things I try changing when looking for accurate loads with the above exceptions. First are powder type and powder charges. Second is seating depth. E