Magna-Trigger from Tarnhelm Supply

Magna-Trigger from Tarnhelm Supply

The Magna-Trigger Safety was designed by Joe Davis and is a modification to select revolvers and prevents anyone not wearing a unique magnetic ring from firing the weapon.  The heart of the unit is a magnetic module that fits into a cut away portion of the front strap of the revolver’s frame.  When a shooter wearing one of the unique rings is gripping the revolver the reverse polarity between the ring and the module permitted the revolver to fire.  The ring has* to be worn on the shooter’s middle or ring finger (dependant on the gun) and can be used with almost any wooden revolver stocks excluding those with finger-groves or any rubber revolver stocks excluding those with a reinforced steel insert steel insert.

A common recommendation is that the shooter wears one ring on each hand to permit weak-hand shooting, and that the revolver be converted to double-action-only since a Magna-Trigger equipped revolver taken away in a single action cocked condition could still fire once.

There are two items of note. First, cutting away a portion of the revolver’s frame will void any Smith and Wesson warrantee, thought for certain special situations I believe it is a reasonable trade-off.  Second, the common handgun disarm method known at the “Walk-through” and practiced by prison inmates could bend the remaining portion of the revolver’s frame sufficiently to disable the safety.  This is possible with long barreled revolvers but very unlikely with the short barreled snub. Overall, for the revolver owner who requires immediate access to a firearm but must weigh that access against the possibility of small children or other unauthorized hands stumbling across the weapon the Magna-Trigger Safety remains a serious consideration.

 Regarding the advice “has to be worn on the correct finger” – that is important. Several years ago I was invited to attend the Lethal Force Institutes (LFI) 20th union. Lt. Adam Kasanof for the NYCPD (now retired) was also a guest lecturer and the only other revolver armed shooter. At the end of the week long event the class participated in a shooting match that required a back-up gun. Well that day Adam had is 4-inch duty gun but no back-up gun. I had a 2 and 1/2-inch snub but no second gun. Well then, naturally Adam and I loaned each other our guns for the match. Unfortunately (for me) I didn’t listen closely enough to Adam’s directions. His K-frame was fitted with a Magna-trigger and he loaned me both rings. He directed me to put them on my middle finger. I sadly put them on my ring finger. Long story short I could not get Adam’s gun to fire untilled I moved the rings to where they were designed to be worn.  Bottom line – The Magna-Trigger worked exactly as advertised.

The Magna-Trigger is available for the K-, L- and N-frame Smith and Wesson revolvers and the Ruger Security Six revolver.

Rick Deviod, owner and chief armorer of Tarnhelm Supply Co., of Boscawen, NH is the only gunsmith licensed to install the Murabio safety. The fee for the instillation is $350.00 per revolver, $60 for each ring plus shipping as of this writing. Rick can be contacted at 603-796-2551 or through his e-mail at