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Posted: 1/25/2016 9:53:20 PM EDT
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I was looking into the very strange issue of Hodgdon lowering their max listings for 10mm loads with 800-X today drastically (more than 12%) compared to the data that IMR listed in the mid-2000s for the powder, and called Hodgdon, when I learned something I hadn't imagined could be the case; the guy told me that while they hadn't tested the 10mm 800-X loads since acquiring the powder line for 800-X and hadn't changed a thing, they listed these lower loads as a safety precaution, due both to their not having tested the load, and because "primers had gotten much hotter in the last 10 years." I had figured that a load that was safe in a cartridge nine years ago with a powder that hadn't changed would still be safe today. This idea that primers are getting hotter, however, is very unnerving for me, as a reloader, who buys quantities of primers every few years. It was over six years ago that I worked up the loads that my AR-10 works best, but now it scares me that when I buy new primers in the future they will no longer produce the same results. Has anyone else heard of this or perhaps encountered the concept that primers are getting more powerful? |
| I have not heard this and have not noticed any pressures signs in differently aged primers. I have only been loading for 5 years or so but I have primers that are well over 10 years old I have used and didn't notice a difference. A majority of my loads are not max if that makes a difference. |
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Don't know for certain if the tech you spoke to is right.
But if he is right, I'll hazard 2 guesses as to what primers he is talking about: 1) foreign primers. Before ammo prices skyrocketed around 2008 (thanks China), there were only 4 commonly-available primers in the USA: CCI, Rem, Win, and federal. Sure, you might look hard enough to find a few others from time to time. But I was paying $68 for 5K Winchester LPP back then - why buy anything but the "big 4" ?? Today, add to the Big 4: Wolf, S&B, Fiocci, and a few others I don't recall. People buy what they can get! Are some of these products hotter than comparable U.S. ones? I can't say but it would not surprise me. 2) "lead free" or "non-toxic" primers. Google it. These use a totally different priming compound. The Wiki page states that these primers have a greater "briscence" or more explosive force. These primers also have a shelf life. The shelf life isn't a conspiracy, it's just a chemical property they are trying to work around. These things are hotter when brand new. Then they go inert after a decade. |
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Yikes! I always hated NT primers and avoided them like the plague, but that was just because of how they have a tendency to snap/blunt/melt the tips of firing pins and strikers! Now I know they have a shelf life and start off nuclear? Damn those tree-huggers! I am strictly a CCI guy, and I stack them deep, so I figure those hotter/less consistent foreign primers aren't an issue for me, and I can proceed, cautiously, with that warmer 800-X load for the 10mm. Also, you mentioned China as causing ammo prices to skyrocket; why is that? |
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Quoted:
Yikes! I always hated NT primers and avoided them like the plague, but that was just because of how they have a tendency to snap/blunt/melt the tips of firing pins and strikers! Now I know they have a shelf life and start off nuclear? Damn those tree-huggers! I am strictly a CCI guy, and I stack them deep, so I figure those hotter/less consistent foreign primers aren't an issue for me, and I can proceed, cautiously, with that warmer 800-X load for the 10mm. Also, you mentioned China as causing ammo prices to skyrocket; why is that? The ammo price jump had something to do with the international "commodities markets" for lead and copper. China bought up all they could for domestic use back when their economy was growing at 11 to 15% a year. That has subsided somewhat. Ammo is still about double the price of what it was in 2005. |
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Here is what I've found on lead free primers:
"Other explosives used in primers can include lead azide, potassium perchlorate, or diazodinitrophenol (DDNP). New on the market in the late 1990s are lead-free primers(see green bullet), to address concerns over the lead and other heavy-metal compounds found in older primers. The heavy metals, while small in quantity, are released in the form of a very fine soot. Some indoor firing ranges are moving to ban primers containing heavy metals due to their toxicity. Lead-free primers were originally less sensitive and had a greater moisture sensitivity and correspondingly shorter shelf life than normal noncorrosive primers.[citation needed] Since their introduction, lead-free primers have become better in their performance compared to early lead free primers, as reported by AccurateShooter.com in October 2011. Tests comparing lead-free primers to lead-based primers conducted by the US Department of Defense (approx 2006), exposed some significant differences in accuracy between the two primers when used in 7.62x51. In these tests, lead-free primers were proven to be not as accurate as lead-based primers. The lead-free primers exhibited poor performance as far as peak blast pressure, which consequently leads to poor ignition. Popularity is still minimal, as accuracy is paramount. Most lead-free primers are sourced through Russia (MUrom?)or South Korea (PMC). Finally, yhis is the culprit compound: http://en.wikipedia.org/wiki/Diazodinitrophenol |
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Quoted: What bullet / max load you talking about 14gr of 800x in 135gr's, or something else? |
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Pressure measurement equipment has become more widely used and more technically accurate over time.
The reduced charges are based on the latest technology and more accurately reflects actual pressures being created. Changing primer brands does have an effect, and that may be part of what's being reported. |
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Powders can change over time as well, especially if the supplier changed or there were factory changes. Also, the powder companies have an acceptable range for lot-to-lot pressure variances. It could be the old testing was done with a lot that was on the weaker side of the range and the new testing was done with a lot that was on the hotter side of the range.
The Western Powders blog just did an article about primer temperature sensitivity. For control rounds at 70 degrees with magnum primers, there was a maximum of 1.8% difference in load pressures between primer brands. If primers have changed that much in the last 10 years, you'd think that there would be more pressure difference between brands (unless all of the brands have changed to being more powerful). http://blog.westernpowders.com/2016/01/primers-and-pressure/ |
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Quoted:
I have not heard this and have not noticed any pressures signs in differently aged primers. I have only been loading for 5 years or so but I have primers that are well over 10 years old I have used and didn't notice a difference. A majority of my loads are not max if that makes a difference. I agree with this. I have loaded tens of thousands and never noticed any difference in primers for the most part. You will get some strange answers from techs. If the future just come here  that's what I have done over the years and can pretty much find what I need by scanning the posts. This is one of the best forums for reloading I have seen.
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