.43 Spanish (Venturino Data)

.43 Spanish (Venturino Data)

The .43 Spanish, also known as the 11.15×57mmR, is a black powder cartridge developed in the 1860s by Remington for use in its famous rolling block rifles, especially those intended for export. Adopted by Spain and several South American countries, the cartridge became widely associated with the Remington Rolling Block military rifles used during the late 19th century — a time when metallic cartridge development was advancing rapidly worldwide.

According to historical data and Mike Venturino’s extensive work on black powder military cartridges, the .43 Spanish used a rimmed, bottleneck case capable of holding a substantial black powder charge — typically around 70 grains of FFg black powder. This case propelled a .439–.446" diameter lead bullet, weighing approximately 370 to 400 grains, to moderate velocities of 1,250 to 1,350 feet per second. These ballistics were quite respectable for the period and offered sufficient energy for both military and hunting purposes, especially at medium ranges.

One of the standout features of the .43 Spanish case was its unique case construction. Original Berdan-primed brass manufactured in the late 1800s by Spanish arsenals or European contractors featured a thick rim and sometimes a paper-patched bullet seated deeply into the case neck. Venturino has noted that the bore diameter of .43 Spanish rifles can vary significantly between examples — a common issue with military surplus rifles — and handloaders are encouraged to slug their barrels before selecting appropriate bullets.

In terms of reloading, Venturino’s published data highlights the use of soft lead bullets cast from molds such as the Lyman 439186 or similar designs. He emphasizes the importance of consistent bullet lube (such as SPG) and careful case preparation — particularly trimming, chamfering, and occasional annealing — to extend case life. Venturino often recommends loading with black powder or black powder substitutes like Pyrodex or Triple Seven, noting that smokeless powders can work when reduced cautiously, but are best left to experienced black powder cartridge reloaders due to pressure unpredictability in antique rifles.

In practical shooting applications, Venturino's experiments show that with proper bullet fit and moderate charges, the .43 Spanish can produce groups in the 2–3 inch range at 100 yards. He often reports success with Swiss FFg and heavy bullets seated over card wads to manage compression and fouling. Given the long throats and generous chambers of many old rolling block rifles, bullet seating depth may need adjustment on a rifle-by-rifle basis for best results.

Though obsolete in military use, the .43 Spanish holds enduring interest for black powder cartridge rifle (BPCR) shooters and collectors. Venturino’s work has helped preserve knowledge of this historical cartridge, and many of his loading practices are still considered the gold standard for safe and accurate shooting with vintage firearms.

Source: Mike Venturino – Black Powder Cartridge Rifle Writings and Data