Grovtec US Inc GTHM74 Horizontal Hammer Extension for 1983 Marlin Steel

The Grovtec GTHM74 is a horizontal hammer extension designed to give you better control and reach on Marlin lever-action rifles. If you shoot a scoped Marlin or just want more comfortable hammer access, this steel extension adds a larger contact surface that makes cocking and handling smoother—especially when your scope or rings are eating into your thumb space. Grovtec builds these to fit specific firearms precisely, so you get a rock-solid fit without guesswork.

Marlin lever-actions are legendary for reliability and heritage, but their compact hammers can feel cramped behind modern optics or in gloved hands. A horizontal extension is the right move when you need that extra reach and leverage, and Grovtec's design mounts cleanly without fuss. The extension can be positioned on either side to suit your preferences and setup.

This extension is engineered for Marlin lever-actions manufactured in 1983 and later—that covers the workhorse models: 39A, 39M, 1894, 1894C, 1895S, 336C, 336T, 375, 444S, and Glenfield 30A. Before mounting, verify your rifle's year and model against that list to ensure correct fit and safe function. Like all Grovtec parts, it's finished to professional standards and built to last.

Key Features

• Horizontal design expands hammer contact surface for easier cocking and control
• Mounts on right or left side to match your shooting style
• Designed specifically for Marlin lever-actions—indexed fit, no improvisation
• Solves scope clearance issues on scoped Marlin rifles
• Quality steel construction and finish

Specifications

Frequently Asked Questions

Will this hammer extension fit my Marlin rifle?

The GTHM74 is designed for Marlin lever-actions made in 1983 and later, including the 39A, 39M, 1894, 1894C, 1895S, 336C, 336T, 375, 444S, and Glenfield 30A. Verify your rifle's year and model before purchase. Do not use this extension on any firearm not listed in its compatibility range—correct fit is essential for safe function.

Can I mount the extension on either side of the hammer?

Yes. The GTHM74 can be mounted on the right or left side of the hammer, so you can position it to match your shooting preference and setup.

Why would I need a hammer extension on a scoped Marlin?

Modern rifle scopes and scope rings can reduce clearance between your thumb and the hammer. A horizontal extension like the GTHM74 gives you a larger contact surface and better reach, so you can cock the hammer comfortably without banging your hand into the scope.