I've read that changing primers can effect accuracy and ES when the right one is found. I've always wanted to test it for my self and am gearing up for it. How do you test your loads with different primers but keep the round count down to save barrel life and components? Since ES is a testing parameter, seems that 5 shot groups would be a minimum.
Testing primers
- Thread starter jrock
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antelopedundee
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Limit your test to a couple of brands. I was told long ago that Remington are the hardest so I would try them and also the Federal 210M match primers. Find someone near you willing to trade a few for a few.
Depends on rifles, if I'm using LR mag primers its Fed 215 or CCI 250. Standard LR I try 210, 9.5 and CCI 200.
Small rifle nothing but rem 7.5
Primer change can make a big difference, I recently did a test using 215 and 250 between RL 26 and H1000 at 500 yards in a 6.5x06AI and the vertical was hands down better with H1000 and CCI 250 over all other combinations.
Small rifle nothing but rem 7.5
Primer change can make a big difference, I recently did a test using 215 and 250 between RL 26 and H1000 at 500 yards in a 6.5x06AI and the vertical was hands down better with H1000 and CCI 250 over all other combinations.
antelopedundee
Well-Known Member
I expect that CCI or Federal benchrest primers would be the most consistent.
Keep the load exactly the same and just switch primers, assuming you aren't loaded on the ragged edge of pressure. Fire them across a chrono and measure ES/SD. Realistically, in a 338 NM or Lapua your choices are Fed 215 or Win Mag. The CCI 250s don't have enough Kapusta for loads over 70 grains. (Not to go into great detail but too many click booms, delayed ignition, or failure to ignite. Get burnt clumped powder but no boom.) If your current load has good ES/SD now, why bother since you seem worried about the component costs. Neck tension and case fill are far more likely to affect ES than the primer.
I couldn't tell any difference in the match 215 versus the regular blue box ones
That is absolutely wrong!
I've ran them all the way up to 89.0 of N570 in my 30-28.
Nope, tried 4 different batches in a 7 RUM, 460 Bee, 375 Ruger and a few others Most had 85 to 105 grains of powder. Regular occurrence of delayed ignition and many failures to ignite even in not all that cold a weather. If you look up the history of the Fed 215, it was specifically developed for Roy Weatherby and the 378 Magnum to ensure reliable ignition of large volumes of powder. You guys can poo poo me all you want but the failure of the CCI 250 in large powder loads is well known and it is REALLY common in them in -10 or colder. Do what you want but please don't try to tell me I don't know what I am talking about when I have tested this extensively. (Google CCI 250 failure to fire and then partial ignition of powder, and see how many others have seen hte same thing)
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