Geissele Defense Pistol GDP 300 Blackout 8" Bbl Black Pistol 08-607B

Geissele Defense Pistol GDP 300 Blackout 8" Bbl Black Pistol 08-607B takes the GDP's compact, GFW-based platform and chambers it for a round built specifically to work in short barrels — supersonic or subsonic, suppressed or not.

The Geissele Defense Pistol GDP 300 Blackout runs an 8" cold hammer forged, chrome-lined barrel with a 1:7 twist on Geissele's tapered profile, paired with a custom pistol-length gas system through an Antistrike Super Compact Gas Block. Geissele's Phased Array® gas system with Tri-Port™ metering keeps cycling smooth across that wide range of 300 BLK loads — a real concern in an 8" barrel, where lesser gas systems tend to run either too hot or too sluggish depending on ammo. A GFW bolt carrier group paired with Geissele's Stressproof Bolt handles the reciprocating side of things, full-auto rated even though this is strictly a semi-auto build.

The Geissele GDP's dual-telescoping brace opens with one motion and locks into two solid positions — no fiddly adjustment required when speed matters. A 7" MK16 M-LOK handguard with Geissele's Center Tab mating keeps the front end rigid, and the SSA X® Wide Body Lightning Bow trigger gives it a break that feels intentional rather than an afterthought on a compact build.

Key Features:

• 8" cold hammer forged, chrome-lined barrel, 1:7 twist, 300 BLK
• Custom pistol-length gas system w/ Antistrike Super Compact Gas Block
• Geissele Phased Array® gas system w/ Tri-Port™ metering
• GFW bolt carrier group w/ Geissele Stressproof Bolt
• SSA X® Wide Body Lightning Bow trigger
• Dual-telescoping GDP brace
• 7" MK16 M-LOK handguard, black finish
• HUXWRX Flash Hider-QD 762

This Geissele pistol is built for shooters who want 300 Blackout's dual-role ballistics in the most compact package Geissele offers.