GHK M4 GBBR (Navy Seal, Keymod MOD1): specs, joules & FPS
Complete specs GHK CO2
GHK M4 GBBR (Navy Seal, Keymod MOD1), CO2: 1.56 J, 410 FPS, 2,610 g, 40 rounds. Full specs from the official source, with FPS for every BB weight.
Power
Above Italy's 1 J limit
Italian shops sell versions tuned below 1 J: ask the shop which version they ship.
Energy computed from the velocity with 0.20 g BBs, the standard weight manufacturers and shops use to measure FPS.
For information only, based on the source's data for this version. Not legal advice: always check current local law and the version the shop sells.
Technical specifications
| Brand | GHK |
|---|---|
| Model | M4 GBBR (Navy Seal, Keymod MOD1) |
| Category | Assault rifles & carbines |
| Power source | CO2 |
| Platform | AR/M4 SERIES |
| Weight | 2,610 g |
| Length | 683 mm |
| Magazine | 40 rounds |
| Hop-up | Adjustable |
Weighs 2,610 g: lighter than 69% of CO2 replicas in the same category in the database (65 with weight).
Similar alternatives
Replicas of the same type and category that stay within the Italian 1 J limit.
| Replica | Energy | FPS | Weight |
|---|---|---|---|
| GHK AK74 GBBR | 0.95 J | 320 | 3,460 g |
| VIVA Arms Mosin Nagant M44 Carbine (Real Wood CO2 Version) | 0.95 J | 320 | 3,760 g |
| RWC GHK M4 SCW GBBR | 1.49 J | 400 | 2,660 g |
| APS TX2 Xtreme GBB | 1.49 J | 400 | 2,710 g |
| APS X1 Xtreme CO2 Blowback Airsoft M4 GBB Rifle | 1.49 J | 400 | 2,710 g |
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 | 410 | 125 |
| 0.25 g | 367 | 112 |
| 0.28 g | 347 | 106 |
| 0.30 g | 335 | 102 |
| 0.32 g | 324 | 99 |
| 0.36 g | 306 | 93 |
| 0.40 g | 290 | 88 |
Theoretical calculation at constant energy (1.56 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
Spotted a wrong or missing value? Let us know.