The only kind of powder that should be used in a muzzleloader is black powder (or a manufacturer‑approved black powder substitute, such as Pyrodex), and never modern smokeless powder.

Below is a Quick Scoop–style breakdown tailored to your prompt.

Quick Scoop: What powder is the only kind that should be used in a

muzzleloader?

Direct answer

For standard, traditional muzzleloaders, the correct and safe choice is black powder , with approved black powder substitutes (like Pyrodex or similar products specifically labeled for muzzleloaders) also acceptable. Modern smokeless powder must not be used in typical muzzleloading firearms because it can generate dangerously high pressures and cause catastrophic failure of the barrel.

In other words: if it’s not real black powder or clearly labeled as a black- powder substitute for muzzleloaders, don’t pour it down the barrel.

Why “only black powder” in a muzzleloader?

  • Muzzleloaders are engineered for the pressure curves produced by black powder, which ignites and burns relatively quickly but at lower peak pressures compared with smokeless powder.
  • Smokeless powder, commonly used in modern rifle and shotgun cartridges, burns differently and can create peak pressures far beyond what a traditional muzzleloader barrel is designed to handle.
  • Because of this, hunter education materials and state manuals emphasize that black powder is the only type of powder that should be used in muzzleloaders , adding that approved synthetic substitutes (like Pyrodex) are acceptable but smokeless powder must never be used.

A typical safety line reads essentially: “Don’t use modern-day smokeless powders in black powder firearms. Smokeless powders can cause serious injury if used in muzzleloaders.”

Black powder vs. substitutes vs. smokeless

Here’s a clear view of what’s generally considered safe and what is not for most consumer muzzleloaders:

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Powder type Use in muzzleloaders? Notes
Black powder (Fg, FFg, FFFg, FFFFg) Yes – this is the traditional and primary recommended powder. Designed for muzzleloaders; comes in different grain sizes (coarse to very fine) for cannons, rifles, shotguns, and priming.
Black powder substitutes (e.g., Pyrodex, Triple Seven, similar products labeled for muzzleloaders) Yes – if marked as an approved substitute for muzzleloaders. Formulated to mimic black powder performance, often with cleaner burning; must be specifically labeled for use in muzzleloading or black powder firearms.
Smokeless powder (modern rifle/shotgun propellant) No – must not be used in typical muzzleloaders. Develops far higher pressure; standard muzzleloader barrels and breech systems are not built for these pressures, creating a high risk of gun failure and serious injury.

Mini safety notes and example

  • Always read the markings on your barrel and your owner’s manual; many barrels explicitly say “black powder or approved substitute only – no smokeless powder.”
  • Stick to powders that clearly state they are intended for “muzzleloading” or “black powder firearms.”
  • Never improvise with random “gun powder” from modern cartridges or reloading benches; those are almost always smokeless blends not meant for a muzzleloader.

Example scenario:
A hunter with a .50 caliber inline muzzleloader chooses FFg black powder or a pelletized Pyrodex charge that is labeled for muzzleloaders, measures the recommended volume, and loads according to the manual. They never substitute in smokeless rifle powder, even if they have it on hand for reloading cartridges, because the pressure curve is completely different and unsafe for that firearm.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.