Steve RA Posted January 18, 2019 Share Posted January 18, 2019 Looks like the SRP (400) won. Thanks for the testing, about the only other test would be a Ransom Rest accuracy check. Link to comment Share on other sites More sharing options...
racer-x Posted January 18, 2019 Share Posted January 18, 2019 I don't have a ransom rest, but am pretty good at 50 yards from bench. I'm evaluating the accuracy of Montana Gold 115 & 124 CMJ's next and will incorporate these 3 different primers into that. The MG JHP's are the 'gold' standard of accuracy - hoping the CMJ's can live up to that. If so, no more picking corn cob out of my JHP's! Also, there wasn't much difference that I can see in the primers regarding flattening. All look good - see pic below. I removed the primers from these case and measured their diameters - interesting, and not exactly what I was expecting. A side note, these CCI500 primers were purchased in 2008. The 550 and 400 primers purchased this week. unfired (all) - .175" CCI 500 - .176" CCI 550 - .179" CCI 400 - .179" Link to comment Share on other sites More sharing options...
vgdvc Posted January 18, 2019 Author Share Posted January 18, 2019 5 hours ago, racer-x said: I don't have a ransom rest, but am pretty good at 50 yards from bench. I'm evaluating the accuracy of Montana Gold 115 & 124 CMJ's next and will incorporate these 3 different primers into that. The MG JHP's are the 'gold' standard of accuracy - hoping the CMJ's can live up to that. If so, no more picking corn cob out of my JHP's! Also, there wasn't much difference that I can see in the primers regarding flattening. All look good - see pic below. I removed the primers from these case and measured their diameters - interesting, and not exactly what I was expecting. A side note, these CCI500 primers were purchased in 2008. The 550 and 400 primers purchased this week. unfired (all) - .175" CCI 500 - .176" CCI 550 - .179" CCI 400 - .179" Thank you for sharing these results. So were these average diamater numbers and what was the variation? Did you notice a difference in velocity between the primers? Link to comment Share on other sites More sharing options...
Steve RA Posted January 18, 2019 Share Posted January 18, 2019 8th column from left on chart. Link to comment Share on other sites More sharing options...
racer-x Posted January 18, 2019 Share Posted January 18, 2019 8 hours ago, racer-x said: Also, there wasn't much difference that I can see in the primers regarding flattening. All look good - see pic below. I removed the primers from these case and measured their diameters - interesting, and not exactly what I was expecting. A side note, these CCI500 primers were purchased in 2008. The 550 and 400 primers purchased this week. unfired (all) - .175" CCI 500 - .176" CCI 550 - .179" CCI 400 - .179" The zero was off a hair on my caliper. Here are the updated results: CCI 500 - .175" (+/-.0005) CCI 550 - .178" (+/-.001) CCI 400 - .178" (+/-.001) New (unfired) primers (CCI500, 550 and 400) all measured precisely .1745" - no variations found All primer pockets measured .172" - no variations found over mixed head stamp brass. All of these primers started out as the same .1745" diameter pressed into a .1720" primer pocket. These results indicate the 550 (SPM) and 400 (SR) primers expanded more than the CCI 500 SPP's. I expected the opposite result since SPP's are generally expected to be softer than SPM or SR. Only explanation I can think of is that these 500's I have (purchased in 2008) are from a batch when CCI built the reputation of having the hardest & most difficult to ignite SPP. Will be interesting to test again with a current batch of CCI 500's... Link to comment Share on other sites More sharing options...
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