Geissele SAG .375 Suppressor Alignment Gage 10-1639-F

Geissele SAG .375 Suppressor Alignment Gage 10-1639-F ensures the alignment of a suppressor to the bore of a firearm barrel, catching a misalignment problem most shooters never think to check for.

This Geissele SAG .375 Alignment Gage works because a suppressor is usually much longer than the barrel-to-muzzle-device interface, so a small deviation at the mounting point translates into a much larger deviation at the suppressor's exit hole. Those small deviations can also compound rather than cancel out, making misalignment worse the farther down the suppressor's length it travels — a real concern on .375-caliber precision and hunting builds where a baffle strike would be an expensive mistake.

Manufactured from hardened steel and ground 0.002" under nominal bore diameter, this Suppressor Alignment Gage helps prevent wear from abrasive powder residue while ensuring precise alignment along its full 18" length. That extended length is what allows for accurate verification of suppressor alignment, which matters more the longer and heavier the suppressor gets. Its purpose is straightforward: verify suppressor alignment before firing, not after a baffle strike reveals the problem.

Key Features:

• Approximately 18" length, .375 caliber
• Hardened steel construction
• Ground 0.002" under nominal bore diameter
• Designed to verify alignment before firing
• Resists wear from powder residue
• Identifies complete pass, partial failure, and complete failure conditions
• Black finish
• Made in the USA

This suppressor alignment gage turns a guessing game into a verifiable check, catching misalignment on a .375-caliber platform before it becomes a baffle strike.