Maruzen M870 Extension Custom Wood Stock Version: specs, joules & FPS
Partial data Maruzen Gas NBB (non-blowback)
Maruzen M870 Extension Custom Wood Stock Version, NBB: 0.45 J, 220 FPS, 2,600 g, 6 rounds. Full specs from the official source, with FPS for every BB weight.
Power
Within Italy's 1 J limit
Estimated energy: the source does not give the BB weight, so we used 0.20 g, the standard weight manufacturers and shops use to measure velocity. With other BBs the value changes: always check with a chronograph.
For information only, based on the energy the manufacturer declares for this version. Not legal advice: always check current local law and the version the shop sells.
Technical specifications
| Brand | Maruzen |
|---|---|
| Model | M870 Extension Custom Wood Stock Version |
| Manufacturer code | n/a |
| Category | Shotguns |
| Power source | Gas NBB (non-blowback) |
| Platform | M870 |
| Weight | 2,600 g |
| Length | 927 mm |
| Inner barrel | n/a |
| Magazine | 6 rounds |
| Hop-up | Fixed |
| EAN / UPC | n/a |
Velocity with different BB weights
At the same energy, heavier BBs leave the barrel slower. Expected velocity with the most common weights:
| BB weight | FPS | m/s |
|---|---|---|
| 0.20 g | 220 | 67 |
| 0.25 g | 197 | 60 |
| 0.28 g | 186 | 57 |
| 0.30 g | 180 | 55 |
| 0.32 g | 174 | 53 |
| 0.36 g | 164 | 50 |
| 0.40 g | 156 | 47 |
Theoretical calculation at constant energy (0.45 J). Real-world values can differ slightly with hop-up and replica.
Data source
The values on this page come from the product page of the shop redwolfairsoft.com, checked on 2026-11-07. The manufacturer does not publish full specs: values may refer to the version that shop sells.
Shop product page ↗ redwolfairsoft.com
Not declared by the manufacturer: Inner barrel.