Originally Posted by
Marshall
@All,
More testing data:
EP Mod 14 50% initiator, 25% oxidizer, 25% fuel (no glass)
Pb(H2PO2)2 25%
Ba(NO3)2 50%
Sb2S3 15%
CaSi2 10%
100%
This does NOT work. I could tell when seating the anvil, that no double salt formation was taking place. The cup only contained a moist goo that easily squished around. So, this is a dead end. On-the-other-hand, the lack of reaction between Ba(NO3)2 and Pb(H2PO2)2 gave me hope that using Ba(NO3)2 in the place of PbO2 would work.
EP Mod 13 50% initiator, 25% oxidizer, 25% fuel (no glass)
Pb(H2PO2)2 25%
Pb(NO3)2 25%
Ba(NO3)2 25%
Sb2S3 15%
CaSi2 10%
100%
This mixture works about the same as EP 9 which it was based on. I encountered one primer that would not fire and discovered a potential problem in my build method. It appears that the packed pellet sometimes does not completely moisten which limits how much reaction takes place. This was proven by scrapping out the unfired mixture for the failed primer, moistening the mixture outside the cup and repacking the moist mixture into the cup (with the dimple removed). After drying, the primer fired normally. I have probably been having this issue all along with all of my test primers. Therefore, I may have to go to wet packing until my tests are completed.
@perotter,
At the moment, I am not using any binder. I have been able to get away with this because the double salt reaction itself hardens and binds the pellet together as the lead nitratohypophosphite crystals form. As this happens during and after the anvil is seated, the resulting hardened pellet makes for a very reliable primer. That is partly why I prefer dry loading and then moistening the packed pellet. I have found that if you delay seating the anvil too long after moistening the mixture, it becomes difficult to seat them because of how hard the pellet becomes. Because of this, in my latest build method, I only moisten 5 primers at a time so I can quickly seat the anvils before the mixture becomes too hard.
Regarding finding/calculating the optimal amount of oxidizer/fuel. I think I have enough guidance from published information on this topic. Experimentation will allow me to hone in on the best ratios to use. However, please share anything you find or calculate on this question.
Marshall