Abstract: A trigger mechanism for a firearm which has a light trigger pull, reliably contains the high forces of the firing pin spring and achieves this with a mechanism which is simple and with few parts. A toggle linkage prevents the firing pin retainer releasing the firing pin whilst still allowing a light pull. It contains no internal sear and no pins within the toggle mechanism. It is adjustable for variations in manufacturing and can cater for various levels of trigger pull force. It realizes considerable economies for production, assembly and repair without sacrificing functionality.