Spine 400 Easton 4MM FMJ vs Spine 500 Easton 5MM Axis: specs compared
Updated 05 September 2026.
9.8 GPI
Spine 400 Easton 4MM FMJ wins on grains per inch
On grains per inch, Spine 400 Easton 4MM FMJ leads: 9.8 GPI versus 8.1 GPI.
| Spec | Spine 400 Easton 4MM FMJ | Spine 500 Easton 5MM Axis |
|---|---|---|
| Model | Easton 4mm FMJ | Easton 5mm Axis |
| Brand | Easton | Easton |
| Spine | 400 | 500 |
| Outside diameter | .234 in OD | |
| Weight | 9.8 GPI | 8.1 GPI |
| Grains per inch | 9.8 GPI | 8.1 GPI |
| Inside diameter | .204 in | .204 in |
| Stock nock | Easton 4mm Microlite nock | Easton X nock (9 gr) |
| Stock insert | Easton 8-32 aluminium half-out (50 gr) | Easton ST Axis HIT insert (16 gr) |
| Point thread | 8-32 | 8-32 |
| Straightness | +/-.002 in (Match Grade +/-.001) | +/-.003 in |
| Suits | a medium draw of roughly 45 to 65 lb | a lighter draw of roughly 25 to 45 lb |
Questions and answers
Which has the higher grains per inch, Spine 400 Easton 4MM FMJ or Spine 500 Easton 5MM Axis?
On grains per inch, Spine 400 Easton 4MM FMJ leads: 9.8 GPI versus 8.1 GPI.
How do Spine 400 Easton 4MM FMJ and Spine 500 Easton 5MM Axis compare?
On grains per inch, Spine 400 Easton 4MM FMJ leads: 9.8 GPI versus 8.1 GPI.