GrovTec GTHM70 Hammer Extension — Marlin 1957-1982

The GrovTec GTHM70 is a hammer extension made for Marlin lever-action rifles manufactured between 1957 and 1982. It provides a horizontal extension to the hammer to increase the contact surface and improve grip and control, particularly useful where an optic reduces clearance. The extension can be mounted on either the right or left side depending on user preference. Each GrovTec hammer extension is specific to the firearms listed in its fitment information and should only be used on compatible models.

Key Specifications

• Fits Marlin Lever Actions manufactured 1957–1982.
• Material is listed as Steel in the product attributes.
• Finish/style is listed as Blued (source also lists Black in attributes).
• Hammer type is Extension.
• Product type is Hammer Extension.
• Mounting is listed as right or left side.
• Dimensions are listed as 1.20 x 2.85 x 4.90 (as provided by source).
• Weight is listed as 0.0313 (as provided by source).

This hammer extension is a straightforward, purpose-built accessory for period Marlin lever actions where added hammer surface or improved ergonomics are desired. Its compact profile and steel construction are intended to integrate cleanly with the original hammer geometry while allowing installation on either side. Buyers seeking a simple, durable solution to improve hammer purchase—especially when running optics—will find this part tailored to those Marlin model years.