A firearms content creator has issued a strong warning against using WD-40 on guns, explaining that the popular penetrating oil leaves behind a persistent, gummy residue that can impair firearm function over time. The advice comes in response to viewer questions following a previous video about a seized .300 upper receiver, where the host emphasized that the product is unsuitable for firearms maintenance despite its slippery properties.

Key Concerns with WD-40

• Temperature range is only passable, not optimized for firearms use
• Grabs gunk effectively but holds it in place rather than clearing it away
• Primary action involves penetrating then drying to leave a protective coating, which combines poorly with its gunk-trapping ability
• Water displacement properties can promote rust at metal-on-metal contact points due to atmospheric moisture
• May damage wood stock finishes by displacing moisture within the wood

Alternative Products Evaluated

The host also addressed several alternative products suggested by viewers. Transmission fluid was deemed unsuitable due to poor cold-weather performance and breakdown at high temperatures above boiling water levels. Red brake fluid, while having good temperature and gunk-moving properties, was rejected because it forms problematic emulsions when contaminated with water. Kroil received a neutral assessment, with the host noting no direct contraindications but lacking personal experience with the product.

Recommended Approach

“When it comes to cleaning our guns, I guess I only really have one rule and that is that you can use whatever you want to clean your gun provided that you get it all out when you’re done,” the host stated. The creator ultimately recommends firearms-specific CLP products for their tailored temperature ranges (such as -49° to 500°), gunk-clearing capabilities, and minimal side effects, while acknowledging personal preference for convenience over multi-step cleaning processes.