Which of the following triggers is considered "non-adjustable"?

The Ruger M77 Mk2 is classified as having a non-adjustable trigger. This means that the trigger pull weight and characteristics are set at the factory and cannot be modified by the user. The trigger is designed for reliability and to function consistently without the need for user adjustments, appealing to those who prefer a straightforward shooting experience without the potential variability introduced by adjustments.

In contrast, the other firearms listed typically feature adjustable triggers, allowing users to customize the trigger pull to their personal preference for weight, length of travel, or reset characteristics. This adjustability is often sought after by competitive shooters or individuals who wish to tailor their firearm to enhance accuracy and comfort.