Mercury fulminate was used for a long time, but lead styphnate has been the primary primer compound since the 1930's.
Part of the problem with mercury is that residue from the priming can weaken brass cases.
Tula and Wolf use “lead free primers” which use DDNP
“To: Atlas Sneezed
Primers are the only component that is truly “explosive, and few companies want to work with mercury fulminate, which has been the ingredient since the 19th century. All those generations, and no one has come up with an alternative to the ugliest of ammo components.
Mercury fulminate was used for a long time, but lead styphnate has been the primary primer compound since the 1930’s.
Smokeless Primers
Part of the problem with mercury is that residue from the priming can weaken brass cases.”
Primer development took some time.
Flint & steel: 1500s
Percussion cap: initial use in 1807 in Scottish sporting guns; initiating element was fulminate of mercury. Military organizations were slow to change over (insufficient reliability, no established manufacturer nor supply, incompatible with training/tradition). US Ordnance did not present a purpose-designed percussion-ignition musket for adoption until 1842.
Metallic Cartridge: 1845 (lead ball stuck into business end of percussion cap). Suitable military cartridges did not come along until the 1860s, and were at first rimfire. Of course, black powder was still the propellant: all of that points to much shorter case life, so it would not have made much sense to reload, even had the components existed.
Centerfire cartridge: 1867-69. Cases could now be reloaded, but the reloading of militarily useful rifle cartridges meant little, as the deep-draw brass fabrication processes central to modern case manufacture lagged. And the mercury fulminate was found to have an adverse impact on shelf life, not to mention reloading suitability.
Nitro propellant: 1886, introduced by the French. Other powers scrambled to catch up. It was hoped that the corrosion problem would be licked, but it was not so.
Circa 1890s: Potassium chlorate (think, head of a kitchen match) replaced mercury fulminate; this extended shelf life and reloadability, but bores still rusted. Nailing down the exact causes took some time, compounded by the severe bore erosion caused by early nitro propellants, and ill-understood metallurgy (compared to today) of fashioning gun barrels. The cause of bore rusting was isolated to the priming compound before WWI, but the discovery and implementation took time.
1927: Remington introduced styphnate priming compound under the trade name “Kleanbore.” Sporting ammunition makers were quick to change over, but again the military lagged. Uncertainty over the stability and shelf-life of the new compounds lingered; US forces fought all the way through WWII and most of Korea with chlorate-primed 30-06 ammunition. The first US small arm to specify non-corrosive priming in ammunition was the M1 Carbine (1941). As late as the 1960s, Frankford Arsenal was still turning out chlorate primers for use in National Match Ammunition; target shooters demanded it, as accuracy results were better.
Styphnate primers are markedly more difficult to manufacture and the chemical synthesis for components is more exacting, demanding investment in plant and personnel that hardly any entrepreneur will tackle (that’s before we get to the ever-tightening standards placed on the making of anything chemical, thanks to EPA etc). Similar difficulties attend the making of nitro propellants. Black powder and chlorate primers are another story. DoD has published technical and field manuals instructing troops on it; the little books (intended for Special Forces or down aircrews, one guesses) were quite the hot seller at gun shows in the late 1970s, in the heyday of survivalism (predates peppers by a generation).
Too, manufacture of anything gun-related is hobbled by tradition more than other industries. The buying public is relatively backward, mulish in its insistence that “older is better” (and that prices ought to return to the levels of four generations back). So capital equipment modernization and personnel training lag; many factories might benefit from updates, but lack the surplus funds and the dynamic spirit to change. By way of illustration on this point: the very first US metallic cartridge was introduced in 1857, to be fired from Smith & Wesson’s first revolver. It was what we now call the 22 Short, and it is still very much in production.
All this just reinforces the natural reluctance of any industrial firm that makes consumer commodities to invest in newer machines or more/better workers, when demand may evaporate, supply of raw materials is subject to official whim, and the regulatory apparatus may negate everything in a heartbeat.