Expanding Full Metal Jacket

Defense

Expanding Full Metal Jacket (EFMJ) bullets appear like standard FMJ externally but are engineered to expand on impact similar to hollow points. Federal's EFMJ line uses a rubber insert under a lead core that compresses on impact, forcing the jacket to open. This design was created for markets where hollow point ammunition is restricted but self-defense capability is still desired. EFMJ feeds like FMJ (important in older or problematic firearms) while providing expansion comparable to JHP. The technology bridges the gap between target and defensive ammunition.

Use Type

Self Defence

Specifications

Core Material: Lead with rubber insert
Jacket Material: Copper (full coverage)
Appearance: FMJ-like external
Expansion: Controlled, similar to JHP
Feed Reliability: Excellent (FMJ profile)
Legal Status: Allowed where HP restricted
Manufacturer: Federal
Best Use: Self-defense in restricted jurisdictions

Comparison

Type	Appearance	Expansion	Feeding
EFMJ	FMJ-like	Yes	Excellent
JHP	Visible cavity	Yes	Good
FMJ	Full jacket	No	Excellent

FAQ

Why use EFMJ over JHP?

EFMJ is designed for jurisdictions where hollow points are illegal or restricted (like New Jersey in certain contexts, or some international locations). It also feeds more reliably in older firearms that struggle with JHP profiles.

Is EFMJ as effective as JHP?

Testing shows comparable expansion and penetration to quality JHP ammunition. Federal's EFMJ consistently expands to 1.5x+ diameter while penetrating 12-14 inches in gel. For defense where JHP isn't available, EFMJ is an excellent alternative.

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