ELDM vs ELDX (construction-wise)

[Petey308]

Hornady ELDX vs ELDM: Construction, Lineage, and Practical Notes​

This thread compares Hornady’s ELDX and ELDM bullets, and how each relates to older Hornady designs (SST and AMAX). Photos will be posted in the first comment for a direct side-by-side view.

Short Summary​

- ELDX — Developed from the SST lineage. Thicker jacket, interlock-style construction, acetyl resin tip, and a slightly more aerodynamic profile for higher BC.
- ELDM — Developed from the AMAX lineage. Jacket thickness and core comparable to the AMAX, with an updated tip and profile for improved BC and extended range.

Construction & Key Differences​

- Jacket thickness: ELDM/AMAX examples ~0.024". ELDX examples ~0.051" with interlock-style feature.
- Tips: Both use Hornady’s acetyl resin tip, improving ballistic consistency.
- Cannelure / interlock: SST had a cannelure. Many ELDX omit it but retain interlock; omitting reduces drag, boosting BC.

Terminal Behavior & Velocity Considerations​

- ELDX: Tougher construction, but can over-expand at very high impact velocities. Performs lesser than the ELDM at ~2000 fps and lower, in regards to overall expansion. Hits a wall around 1800 fps for reliable expansion.
- ELDM: Expands more reliably at reduced velocities (~1800 fps to around 1400 fps). Best suited for extended-range impacts or lower impact velocities.

Notable Exception​

The 285 gr .338 AMAX (and its ELDM successor) are built more like ELDX bullets, with a thicker jacket and interlock. Treat them like ELDX for terminal performance.

Practical Guidance​

- Sectional density (SD) is important for close-range, high-velocity shots.
- Tougher jackets or bonded bullets may require lower SD to avoid over-penetration.
- Match bullet construction and weight to your expected impact velocity and game size.

Quick Comparison Table​

Bullet	Lineage	Jacket Thickness	Core	Tip	Special Features	Velocity Window (approx.)	Best Use Case
ELDM	AMAX	~0.024"	Pure lead	Acetyl resin	High BC, match profile	Expands down to ~1400 fps	Extended range, low-velocity impacts
ELDX	SST	~0.051" (tapered)	Lead w/ interlock	Acetyl resin	Thicker jacket, higher BC	Performs well above ~1800 fps	General hunting, closer to mid-range
SST	Hunting design	~0.051" (tapered)	Lead w/ interlock	Polymer tip	Has cannelure	Similar to ELDX but lower BC	Close to mid-range hunting
AMAX	Target design	~0.024"	Pure lead	Polymer tip	High BC (discontinued)	Same terminal as ELDM	Long-range target & hunting (legacy)
285 gr .338 AMAX/ELDM	Hybrid	Thick jacket + interlock	Lead alloy	Acetyl resin	Constructed like ELDX	Treat like ELDX	Large game, high energy impacts

Photos & Test Notes​

I’ll post side-by-side photos of ELDX, ELDM, and AMAX in the first comment. Each will include measurement details.

 

[Petey308]

 

[Guffawk]

“Terminal Behavior & Velocity Considerations​

- ELDX: Tougher construction, but can over-expand at very high impact velocities. Performs better than ELDM at ~1800 fps and lower.
- ELDM: Expands more reliably at reduced velocities (~2000 fps and below). Best suited for extended-range impacts.”

Is there a typo here under eldx? I thought the ELDM had the better lower velocity performance?

 

[Petey308]

“Terminal Behavior & Velocity Considerations​

- ELDX: Tougher construction, but can over-expand at very high impact velocities. Performs better than ELDM at ~1800 fps and lower.
- ELDM: Expands more reliably at reduced velocities (~2000 fps and below). Best suited for extended-range impacts.”

Is there a typo here under eldx? I thought the ELDM had the better lower velocity performance?

Yes, not sure what happened there to be honest. I fixed it though. Thank you for pointing out that error.

 

[Wally243264]

Yes, not sure what happened there to be honest. I fixed it though. Thank you for pointing out that error.

Would it be safe to assume the jacket wall will vary with different caliber bullets? For example, a 6mm ELD-M vs a 30 caliber ELD-M.

 

[Petey308]

Would it be safe to assume the jacket wall will vary with different caliber bullets? For example, a 6mm ELD-M vs a 30 caliber ELD-M.

It will, but only slightly and not enough to make a significant difference. I’ve noted the ones where it’s an actual significant difference- such as the 285gr ELDM in .338”. That one is built more like an ELDX.

Any other ELDMs and ELDXs I’ve sectioned in varying calibers only vary by around .001-.002” at the most.

Great question though.

 

[Wally243264]

It will, but only slightly and not enough to make a significant difference. I’ve noted the ones where it’s an actual significant difference- such as the 285gr ELDM in .338”. That one is built more like an ELDX.

Any other ELDMs and ELDXs I’ve sectioned in varying calibers only vary by around .001-.002” at the most.

Great question though.

Thank-you for the quick response! Your post was very informative.