FX DRS 500 Base, PCP, .177 (4.5 mm)

The FX DRS 500 Base is the action from the first generation of FX's DRS platform: action, trigger and a 500 mm barrel in .177 (4.5 mm) – supplied without a stock. It is intended for shooters who want to build their own PCP rifle around a chassis or stock of their choice, for example a compact, light setup for pest control or practice on the range.

What makes the DRS special is that the air reservoir sits as a shroud around the barrel instead of as a bottle beneath it. The profile is significantly lower, and the action takes up less space in transport. With its 500 mm barrel, it is the shortest DRS Base in the first generation, and the reservoir holds just over 200 cc. It is cocked with a sidelever on the right, and the mini magazine allows very low scope mounting.

The technology in the DRS 500 Base

The same adjustment options as a complete DRS rifle.

• Reservoir in the barrel shroud: The air sits around the barrel rather than in a separate cylinder, which lowers the height over bore and keeps the weight close to the barrel's axis.
• Externally adjustable AMP regulator: The AMP MkII regulator is adjusted from the outside, so working pressure can be matched to your diabolo or slug. Stable pressure gives consistent velocity from shot to shot.
• Adjustable hammer spring: Without a stock fitted, you have access to the hammer spring preload. More preload holds the valve open longer and lets more air through – the aim is pressure behind the projectile all the way out without wasted air at the muzzle.
• HP plenum and Superior liner: The 500 has FX's High Power plenum between regulator and valve. The Superior liner with Smooth Twist X (STX) rifling pressed in from the outside gives a smooth bore, low friction and a good seal.
• Adjustable two-stage trigger: Both stages can be set, and the blade can be moved and rotated to suit your stock. The barrel has a ½ UNF thread with thread protector for an optional moderator.

Maintenance and safety

• Only fill with clean, dry compressed air via the fill port on the right, and do not exceed the maximum fill pressure of 230 bar.
• Check the O-rings at the fill port and magazine regularly, and replace them at signs of wear or leaks.
• Adjust the regulator and hammer spring in small steps, and check the result with a chronograph before using the action.
• Store the action unloaded and out of reach of children. Check the air rifle regulations in your country before purchase.