Artemis Snowpeak GU1200S 4.5mm — Gas-Spring Rifle with Under-Barrel Cocking
The GU1200S is a purpose-built 4.5 mm gas-spring rifle featuring an under-barrel cocking lever that keeps the barrel fixed to the receiver during the cocking cycle. That means when you mount an optic or red-dot, the barrel axis and aiming line remain aligned through reloading — the typical post-reload deviation found in break-barrel designs is effectively eliminated. For shooters who demand consistent point-of-aim after every shot, this design is a clear advantage.
Compared with its breaking predecessor (the GR1200S), the GU1200S uses a high-quality steel rifled barrel and a gas spring instead of a coiled wire spring. The gas spring significantly reduces vibration on discharge, improving shot-to-shot accuracy and delivering a predictable feel. The trade-off for the under-barrel mechanism is slightly more mass and length — this model is 360 g heavier and 20 mm longer than the GR1200S — but many users accept that for the stability and precision gains.
Built for both recreational plinking and competitive shooting, the GU1200S comes with an automatic safety, an adjustable sight bar with fiber-optic front sight, dovetail optics rail, and a durable polymer stock and bedding. It uses standard 4.5 mm lead pellets and puts them out at an initial velocity of about 305 m/s — a versatile performer for range time or sport.
Key Features
| Feature |
Benefit / Note |
| Action type |
Gas-spring — reduced vibration vs wire spring |
| Cocking system |
Under-barrel cocking lever — barrel remains motionless |
| Barrel material |
High-quality steel, grooved (rifled) |
| Optics mounting |
11 mm dovetail rail for optics/collimators |
| Sights |
Adjustable sight bar + front sight with fiber-optic threads |
| Safety |
Automatic safety for safe handling |
| Stock / Bedding |
Polymer — durable and lightweight |
| Ammunition |
4.5 mm lead pellets |
| Use cases |
Recreational and sports shooting |
| Compared to GR1200S |
+360 g weight, +20 mm length |
Specifications
| Specification |
Value |
| Type |
Gas-spring |
| Caliber |
4.5 mm |
| Initial bullet velocity |
305 m/s |
| Sighting devices |
Adjustable sight bar with front sight (fiber-optic) |
| Number of charges |
1 |
| Safety |
Automatic |
| Stock / Grip material |
Polymer |
| Type of cocking |
Under-barrel lever |
| Optics rail |
Dovetail 11 mm |
| Barrel length |
480 mm |
| Barrel type |
Steel, grooved (rifled) |
| Total length |
1170 mm |
| Weight |
3.15 kg |
