ManyInterests
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long-term storage of mercury fulminate
I have been meaning to make mercury fulminate for firearm primers for a while now.
I originally planned on making the fulminate last, but my curiosity in making it is getting the better of me. The process for making and purification
all seem simple enough, and I am aware that this is probably the most sensitive primary I will ever be making (except for maybe lead styphnate). So I
am wondering about the long term stability of mercury fulminate. I saw some youtubers store the fulminate in small plastic bottles with screw on caps
and also added water, which renders the culminate unable to detonate or burn. Is this a viable method of storage? Or will prolonged water exposure
degrade it over time?
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greenlight
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Mercury fulminate is not used in primers at all anymore as far as I know. Bullet primer composition is based on lead styphnate now. It would
probably be easier and safer to make a priming composition using lead styphnate, if you can acquire resorcinol it can be made from that.
Regarding the storage of mercury fulminate though, it seems it stores well at normal temperatures under distilled water.
From a quick check of primary explosives, it states that a study done shows a decrease in purity from 99.6% to 98.3% and a decrease in brisance of 6%
over 5 years when stored in this manner.
The purity of 99.6% refers to the white form of MF
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ManyInterests
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Quote: Originally posted by greenlight  | Mercury fulminate is not used in primers at all anymore as far as I know. Bullet primer composition is based on lead styphnate now. It would
probably be easier and safer to make a priming composition using lead styphnate, if you can acquire resorcinol it can be made from that.
Regarding the storage of mercury fulminate though, it seems it stores well at normal temperatures under distilled water.
From a quick check of primary explosives, it states that a study done shows a decrease in purity from 99.6% to 98.3% and a decrease in brisance of 6%
over 5 years when stored in this manner.
The purity of 99.6% refers to the white form of MF
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I am aware that mercury fulminate is no longer used in firearms primers. Also I do have around 200g of resorcinol, which is beyond a lifetime supply
if the only thing I want to make with it is lead styphnate.
I do intend on also making lead styphnate based primers, but I also want to try out mercury fulminate even if it isn't technically the best (mercury
fulminate tends to make the brass more brittle and prone to rupture, and also more limits the life of reloaded cartridges). The reason why is just out
of curiousity and experimentation. Another reason is I found a lot of old-school mercury thermometers and tilt switches with mercury. I feel like I
need to do something with it.
Also isn't white MF technically less sensitive to friction and impact than lead styphante?
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greenlight
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Was that the the primary reason for its discontinuation? Compromising the structural integrity of brass casings?
Interesting.
It appears that lead styphnate is definitely more sensitive to friction than white mercury fulminate and brown mercury fulminate. The white and brown
fulminates are quite close in sensitivity to each other as well.
Lead styphnate is recorded as having less sensitivity to impact though, requiring more Joules of energy than mercury fulminate.
This data is from charts with a couple of sources too not just one.
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ManyInterests
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| Quote: Originally posted by greenlight | Was that the the primary reason for its discontinuation? Compromising the structural integrity of brass casings?
Interesting.
It appears that lead styphnate is definitely more sensitive to friction than white mercury fulminate and brown mercury fulminate. The white and brown
fulminates are quite close in sensitivity to each other as well.
Lead styphnate is recorded as having less sensitivity to impact though, requiring more Joules of energy than mercury fulminate.
This data is from charts with a couple of sources too not just one.
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Partially. The other issue is the thermal stability of mercury fulminate and the long-term storage (older primers with mercury fulminate tend to
degrade over years, which leads to reliability issues), and also the possibly corrosive qualities of mercury discharge.
Lead styphante is much easier to use in making non-corrosive primers and also has much better long-term stability that allows for high performance
cartridges that can be stored for decades before they're needed. The military needs to know how well they store especially. If you are in a place
where old Com Bloc rifles and pistols are available, you will also find that there are still a LOT of old surplus ammunition that works perfectly.
Problem is, they used old corrosive ammunition which can lead to problems if you don't clean your gun sufficiently.
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