Testing White River and OFV primers

[John Weigel]

OK, straight up – this skinny data-set raises as may questions as it answers. But I figured it was worth sharing its rough-and-ready indications anyway, given the insecurity of components supplies - and recent appearance of two new options in large rifle primers in Australia: American-made White River, and Indian-made OFV military grade primers. This first look at the two new boys in town follows earlier similar tests of CCI BR2s and Federal GM210MS (viewtopic.php?f=5&t=15035#p109438). This time around, after noticing considerable variation in cup thickness, I included back-to-back 5-shot groups with each of the three defined primer weights (test 1 – relatively light weight, test 2 with medium, and test 3 with relatively heavy weights). I expected the high variation in primer thickness in the two new products to translate into larger groups, but that didn’t really happen in any obvious way. None of the results are presented with pretty graphs yet, nor can much be concluded yet. I’m planning on a deeper and more thorough test when I get some time.

Absolute group sizes in attached images don’t mean as much as they would had I taken time to develop specific load and tuner settings for each primer (which I’ll do next time), though interestingly, I was tuned for the CCI BR2s - which didn’t win the small-group gong as expected. Also, as found in my earlier tests, there are definite sweet-spots for primer seating depths, and I chose one that works OK for that rifle, those (uniformed) primer pockets, and CCI BR2 weight sorted primers.

I used a semi-retired 7 SAUM barrel on a Barnard long action, shooting 5-shot groups during a three-hour period at St Mary’s indoor 50m range, fan-cooling barrel after every 15 or 20 shots. I cleaned barrel using patented five-minute back-to-metal method using patched brush with Sweet’s/abrasive mixture that I posted about previously before each group of 35 primers, with 5 foulers shot onto a separate target pre-test, though I saw no real difference in group sizes for these – e.g. the ‘warm up’ 5-shot group that preceded the scary .7 MOA (.35” at 50m) (Target 1 - mixed lot of weights of CCIs) was less than 3 MOA. For each primer type I established and stuck to a primer seating depth that created 2-4 thou crush for a nominal primer thickness - approximately average, from the tested sample of primers. I drew the CCIs and OFVs from a single packet of 100 each; I sampled two packets of White River primers, purchased at two locations, because on inspection I found that the two packets had surprisingly different average weights. Spoiler alert, if sorted by weight, it doesn’t seem to matter. Clearly a more detailed test will sample from lots of 1,000 primers to get an idea of how far outliers may lay – as I’ve demonstrated previously, in the bricks of CCIs and Feds I tested, there were a few potential match-spoiling weight extremes in each, with over 50% variance in the weights of the non-metalic elements. Although I collected a bucket-load of weight and size data for the primer components before and after use, but don’t see the value of crunching at this stage, having concluded that cup and anvil weight variation for CCI and WR is very tiny, with the variation all present in the soft compounds. Slightly different story with the Indian primers, but not enough to get excited about.

Although there are some half-descent groups for each of the three tested brands, what you can’t as easily see is a shifting of point of impact among some of the three weight-classes of each primer type – which should further help to convince holdouts (including most of the guys on my team!) as to the value of primer weight-sorting. Also, softly, it looks like those good ‘ole boys down in Arkansas may be onto a good product, and maybe we are too. And at least the heaviest of the OFVs have shot well so far.

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[Pablolig]

Adding to your good work, I managed to weigh 200 OFV primers yesterday. No testing done as yet, but I just thought that starting from a known base, will help.
I used an A&D 300 set of scales.
Weigh are in grams.

More to follow