Geissele .375 Caliber Suppressor Alignment Gage

The Geissele .375 Caliber Suppressor Alignment Gage (brand part no. 10-1639-F) is a precision fit-check gage used to confirm a suppressor mount or adapter is properly concentric with a .375-caliber bore before the suppressor is ever fired. Geissele Automatics builds this gage as a safety verification step rather than the suppressor mount itself, catching a misaligned thread or baffle stack before it becomes a baffle strike downrange on a large-bore rifle host. This is not an NFA-regulated item; it’s a gunsmithing verification tool that any builder can own and use without special paperwork, even though it’s sometimes filed alongside suppressor parts. Stock it with the rest of our gunsmithing tools and gunsmith supplies for large-bore suppressor-host rifle builds.

Key Specifications

• .375 Caliber Bore Sizing Ground specifically to check alignment for this bore diameter.
• Alignment Verification Function Confirms a suppressor mount or adapter is concentric with the bore before live fire.
• Pre-Fire Safety Check Used as a build-verification step rather than a suppressor part itself.

Frequently Asked Questions

Why does bore size matter for which gage I buy? Each gage is ground to a specific bore diameter, so the .375 caliber version won’t give an accurate reading on a different bore size.

Do I need an NFA transfer to buy this gage? No, this is a gunsmithing verification tool, not the suppressor itself, and requires no special paperwork to purchase or own.

Buy the Geissele .375 Caliber Suppressor Alignment Gage

Large-bore suppressor hosts deserve the same alignment diligence as any other caliber. Order this gage from our Lubbock, Texas gun shop for fast, insured shipping to your bench.