Been reloading for a while but am no means a expert. I was wondering who prefers what for primes and what ones you hate. Do primers manufacturers matter for amount of powder used? Example this brand works good in 308 and smaller this brand works better with magnum calibers 80+ grains of powder?
I keep a variety of primers on hand for load development. Federal, CCI, Win., and some Rem's. I have seen groups shrink by a simple primer change. I guess I don't hate any brand, and I like the ones that show me tighter groups and lowest ES. I have found it worth while to load a few rounds with a different primer to see what I get.
After I work up an accurate load I try a different primer to determine If I may improve, I can honestly say I have never seen significant improvement by a simple primer switch, like over .25 MOA on a a .5 or .75 MOA load. Small improvement yes, ES like Broz said yes witch is important at distance (Thanks, made me think about this a bit more than just accuracy at 100 yards)
In the big stuff (magnums with 60 Grns plus powder) I prefer CCI Mag primers to anything else. They have provided the best consistency and are my go to. In the small stuff I also prefer CCI or CCI BR because of the consistancy and packaging. I use a lot of Federal Primers but HATE the packaging, difficult to get into the trays.
Again personal experience but I have noticed a difference in BR primers in small rifle but not as significant difference in large rifle. That said I mostly use BR primers anyway and others will have different experience.
Find a primer thats readily locally available, cost effective and works and use that for your foundation would be my recommendation. Federal seems to be a go to among the BR guys and the most availible in my market.
It's an abstract, unpredictable, and leading to trial & error.
I think firing pin stiking, and boltface & pocket seating could be adjusted to make any particular primer work, but not with just any load. Re-load development would still be in order, as it is with bullet changes.
Trial & error..
We ARE very lucky to have all these primers available though.
This was one of the biggest improvements I have seen, and it followed the same with more test groups. This was load development at 200 yards for my 6mmbr. Note group #1 and #3 are the same load with only the change of a primer. Group 2 was a seating depth change. I will agree that most gains or losses are not this drastic. But this remains in my mind and urges me to try different things.
For me, in Large Rifle and Large Rifle Magnum, Winchester primers have given the most consistency in accuracy and ES. They are usually what I start with but do try several groups with others to make sure I'm not missing something.
In my varmint / coyote loads (small rifle size primers), I seem to gravitate toward CCI BR primers.
I had the same shift as Broz demonstrated -and even without changing primers! The root cause(which was not easy to determine) ended up being a slipping set screw on the firing pin in the cocking piece. Once I found this, and also found that I had no reference for setting it back to load developed performance, I did some experimenting. What an opportunity!
I measured the released firing pin to boltface and tweaked the pin setting back into and through best performance. There was one place(from either side of adjustment) where everything came together with my best load, and now it was better than ever. Log that setting!
Then I changed to another primer and repeated the adjustments at the range and sure enough found a setting that worked really well with that different primer, and it was a different setting.
Just by chance(I think) my original primer choice & load performed best at it's setting so that's what I ended up going back to. But this may have been due to my set pocket depths and seated primer crush, being more/less ideal for one primer over another. All would also be affected by the trigger(as Kelby's testing elludes to).
There is a helluvalot to learn here, and until then, I say it's all as abstract as bullet seating adjustments.