Gunsmith Bros GB01 TF Aluminum 5.5 inch GBB: specs, joules & FPS
Complete specs Gunsmith Bros GBB (gas blowback)
Gunsmith Bros GB01 TF Aluminum 5.5 inch GBB: 1.27 J, 370 FPS, 710 g, 31 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 | Gunsmith Bros |
|---|---|
| Model | GB01 TF Aluminum 5.5 inch GBB |
| Category | Pistols |
| Power source | GBB (gas blowback) |
| Platform | CZ75 |
| Weight | 710 g |
| Length | 245 mm |
| Magazine | 31 rounds |
| Hop-up | Adjustable |
Weighs 710 g: lighter than 75% of GBB replicas in the same category in the database (466 with weight).
Similar alternatives
Replicas of the same type and category that stay within the Italian 1 J limit.
| Replica | Energy | FPS | Weight |
|---|---|---|---|
| Novritsch SSP18 Gas Blowback Pistol | 0.95 J | 320 | 735 g |
| RWC Inokatsu M&P9 Steel Slide Custom | 0.95 J | 320 | 760 g |
| Novritsch SSP28 Split-Slide GBB | 0.95 J | 320 | 823 g |
| VFC SA 320 | 0.81 J | 295 | 675 g |
| G&G GTP 9 | 0.84 J | 300 | 770 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 | 370 | 113 |
| 0.25 g | 331 | 101 |
| 0.28 g | 313 | 95 |
| 0.30 g | 302 | 92 |
| 0.32 g | 293 | 89 |
| 0.36 g | 276 | 84 |
| 0.40 g | 262 | 80 |
Theoretical calculation at constant energy (1.27 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.
Available colours
The same model is also sold in these colours. The specs on this page refer to the first version; each colour links to its own page at the source.