Primer Test Part 2
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LOOK at those craters!!!!!!! I can't recommend running these primers with this hot of a load of H4350, in this rifle.
CCI #41 Small Rifle primers performs as follows.
MV: 2808
SD: 5.3
Group Size: .738 MOA (with one called flier)
Primer Crater: Absolutely None discernible.
Other signs of overpressure: Extremely minor case head shine.
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Beautiful, no cratering whatsoever!!! Yes, these babies are gold colored.
CCI #450 Small Rifle primers performs as follows.
MV: 2793
SD: 7.2
Group Size: .33 MOA
Primer Crater: I could feel 6 of 10, all felt larger and more pronounced than the Federal GMM, but not as bad as the CCI 400’s.
Other signs of overpressure: Minor case head shine.
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Yowza! Crater city!! Same thing, too hot for me with these primers too!!
Some surprising results, the MV decreased across the 4 groups, with the Federal GMM delivering good primer performance and low cratering.
The SD was good for all 4 groups. Some better than others, each group was only a 10shot group, so more research needs to be done on SD.
Group sizes were all good. Interestingly the 2 best groups were with the CCI 400 and CCI 450's. Too bad they are showing so much cratering. The close up pics really demonstrate how bad the cratering is. Some groups were tighter than others, all were great groups, variance is most likely the shooter.
Primer performance: Federal GMM Small Rifle and CCI 41 performed much better with regards to less cratering than ether CCI 400 pro CCI 450’s. If you are wanting to run Lapua Brass and a slightly hot load, you might want to stick to one of those 2 options, with CCI 41 (unsurprisingly) being the toughest of the bunch.
All 4 batches showed very little evidence of overpressure on the case itself, again unsurprising as many on this forum are running their CM's hotter than I am. Always use caution with working up loads, and keep in mind H4350 table values are 40.0 to 42.0 grains!!!
At the very least, if you're having issues with cratering you might consider one of the better performing primer options.
I hope someone finds this info useful!
Cheers,
Dark