Choosing And Fitting Triggers

I don’t know if Davy Crockett adjusted his rifle trigger for a smoother release but chances are he did. Ever since folks began contemplating long range work with the rifle they have addressed the need for a light crisp let off to allow them to hold the sights steady as they pressed the trigger. On the other hand, military men remain frightened of the troops using a light trigger. Heavy two stage triggers are the rule there.

This can be an aid in marksmanship when the nerves are rattled or when wearing gloves but sometimes these military rifles end up in the hands of sport shooters. We are used to lighter and Below center: Some aftermarket trigger assemblies demand more work than others, depending on the rifle, but in the end this is the author’s recommended procedure. crisper trigger actions on commercial actions. When military actions were cheap and plentiful the trigger gets lots of attention.

There have been plenty of military rifles in the hands of sportsmen who despised the original triggers. The two stage trigger is a good choice for the military and not a bad choice for hunters using rifles at moderate range, especially those hunting in cold climates with gloved hands. You always know that you are in control with the two stage trigger. There is a bit of take-up and then the final compression. Still, for top accuracy there is no question that a lighter, crisper trigger action is needed.

Some have taken the path of modifying the original trigger action by polishing the sear. I prefer to replace original two stage triggers and not modify them. While this may be a controversial statement in some quarters, the availability of modern triggers leaves no profit in attempting to tune a two stage trigger given the time and effort. I have come to feel much the same concerning the 1911 trigger action in pistols and use quality ignition sets rather than modifying the original.

The good gunsmiths that attempted to modify military triggers, such as the late T. N. Hughston, knew exactly what they were doing. Others did not. There are those that have successfully and safely modified Mauser-type military triggers. Before you begin to modify a two stage military trigger it would make sense to completely understand what the trigger is and what it does. The original design of the two stage trigger allows quite a bit of take up before the trigger action begins breaking the sear.

The design is relatively simple. There are two rises or bumps on the trigger bar that create the two stages. For those

Above center: The AR-15 is full of pins and parts. It pays to keep a few on hand. wishing to modify the existing trigger it is obvious that elimination of the first stage is the only way to improve the trigger or create a sporting trigger from an original Mauser type as commonly found on the ’98 and others. The take up stage involves pressing the trigger enough to just begin sear movement. The next stage actually trips the sear.

A sport shooter simply wishes to eliminate the first stage which can be done by grinding the first rise or bump off. However, all we have done is decrease take up. The trigger may still be heavy. In order to both eliminate the initial take up and also to produce a smoother trigger action, lighten or cut the sear spring for lighter trigger compression. This can make for a light, Watching the movement of the cocking knob is a good means of gauging the action.

Far even crisp, trigger but when this modification is performed there often is a problem with the proper sear reset. If the sear doesn’t reset properly the trigger action may be inconsistent.

The rifle may go off too early or the weakened sear spring may even induce a negligent discharge. (As an NRA certified instructor, I do not recognize the term "accidental discharge." Most are negligent discharges.) Sear engagement may appear fine at first but the elimination of some metal from the sear spring may leave the sear inconsistent. The reason for this is that the cocking piece and the sear do not always mate perfectly each time and the ratio is increased with the modification of the sear and sear spring.

You really need to observe a modified rifle in action and watch the

cocking piece, observing for consistent lockup. It may not always move the same amount with a modified trigger action. Why not simply install a modern trigger assembly that offers a wide range of adjustment? These replacement units are designed to replace the original trigger action and behave like a sporting trigger. Triggers such as the Timney offer a good tight fit, are precision machined and offer good adjustment. The sear is a different design from the military makes with a true sear bar operating the sear.

The sear bar is a fulcrum design that is seen moving forward and downward. Much less pressure is needed to trip the sear bar with this type of design. As such the need for extensive sear engagement is negated. It is not unusual to address the custom trigger with an action of three pounds or less, versus five to six pounds with the military trigger. While it is aside issue, the new style trigger also makes the installation of a modern sporting safety much easier. How do you install the new trigger assembly?

Mausers have across pin holding the trigger in place. Simply tap out the cross pin and remove the old trigger assembly. The new trigger assembly is pressed into the old recess and the cross pin is driven back into place. There is a lock screw that needs to be tightened at the front of the housing. Sometimes a little stock modification is needed. There is a range of adjustments in these triggers. A bit of creep may prevent the shooter from completely controlling the trigger.

While surprise break is good in theory, a good shot should know exactly when the trigger will break. The operator will control the trigger. An abrupt stop is also bad news, as this may cause the rifle to move just as the shooter fires. Remember, reducing the trigger weight of factory triggers by filing or polishing also reduces contact points. This isn’t safe. While modern triggers area great boon to general shooting chores their use in a true hard use rifle should be carefully weighed.

An important concern is that the modern trigger is more enclosed as opposed to the more open style of the military trigger, allowing an accumulation of crud and debris in the enclosed housing. Sometimes a mix of crud will impede a good trigger action, other times it will actually stop the trigger. I have seen triggers that were practically glued shut and quite a few more that were so tight they demonstrated approximately double the original trigger press.

On the other hand, the original military trigger action is among the most reliable ever fielded. Be certain that you understand exactly what the customer wants and needs and where they are heading. Then be certain they understand that the finest aftermarket almost always is more prone to fouling than the original. Finally, explain the trigger guard may have to be enlarged and the stock modified for installation. Step By Step Timney triggers are popular, work well and are affordable.

The Timney is indicated even with rifles already having so-called adjustable triggers because some simply cannot be adjusted to preferred levels. The Timney is usually adjustable from 1.5 to 4 pounds pull and features an over travel adjustment. Construction is of 440C stainless steel. The final fit and finish appear good in every unit I have examined. The kit for most rifles comes with the trigger, sear, spring and Allen wrench. The first step is to remove the action from the stock.

Then there are action pins that must be drifted out with a small punch to free the trigger. These are usually driven out with 1/8 inch punches. In some cases, all that is required is to push out the pins with the supplied Allen wrench. Next, match the trigger to the factory safety. Specifics unique to your rifle American Gunsmithing Association

Above center: The AR-15 receiver isn’t exactly fragile but it is aluminum. Do not force pins into place. Use quality parts and the result will be a considerable improvement in crispness and control. are in the included instructions. As directed, file a section of the trigger so that it mates properly with the safety. If you take off excess material the rifle may fire even with the safety activated! The safety will not engage until sufficient metal is removed by the cut and try method.

When the rifle trigger is correctly installed and the rifle is cocked there is no take up in the trigger at all. In most cases several attempts are needed to get this operation correct. When properly done the parts are in contact and only lightly touch. The goal is to prevent binding but never leave a gap between the safety and the trigger as this would allow a dangerous situation in which the rifle might fire when the safety is engaged. There are variations in the triggers that are worth noting.

The Timney, as an example, features a small adjustment setscrew that can control sear engagement depth. However, the setscrew can sometimes be very difficult to convince to move. Jared’s trigger features very small adjustment screws for sear engagement, over travel, weight of pull and offers good adjustment. Quite a number of AR-15 rifles come into the shop for trigger jobs. There are also a number of aftermarket triggers available. One of the triggers I count on is from Wilson Combat.

This trigger is usually a drop in unit, turning the AR-15 into a solid sporting rifle. Installing anew AR-15 trigger isn’t really much more difficult than a simple clean and lubrication. The two pins to worry about are the trigger pin and the hammer pin. This is a job that calls for careful hand fitting. If these pins don’t quite fit on installation, don’t force them. The pins may need to be polished on the edge but nothing more. I test fit the pins before installation. They should press into place freely.

The pin holes and the holes in the hammer and trigger should be lightly greased before we begin. Lower receivers aren’t as robust or hard as steel receivers and can be damaged. The safety lever should be in the fire position as you begin your work. After stripping the old trigger assembly from the receiver, place the trigger carefully into the lower receiver. As you do so, be certain that the return spring remains in position. The disconnect spring also must remain in place.

The rear or tail of the trigger assembly will be placed under the safety bar. The disconnect is placed and the holes are lined up. I use an assembly punch. Press the punch from left to right. The punch runs into the trigger but not the disconnect channel. Position the disconnect. Pay close attention to the position of the disconnect spring. By pressing the disconnect downwards the positioning hole lines up with the trigger hole. Begin to press the pins in from right to left as the punch holds the pieces in place.

After seating, the parts should move normally. If not, check the springs. The legs of the hammer spring should point to the rear of the AR-15’s receiver. These legs ride on top of the trigger pin. The right hand leg keeps the trigger pin from coming out by riding a groove. To fully seat the pins keep the hammer pressed down and forward as you seat the pins. Now do the safety check. Remember, the safety can only be applied in a properly operating AR 15 when the hammer is cocked.

The trigger is pressed while the safety is on and the hammer should not fall. While maintaining pressure on the trigger, move the safety to the fire position. The hammer should not fall. Release pressure on the trigger and then press again, while holding the hammer with the fingers. The hammer should fall. Watch the hammer as you release the trigger. The hammer should be forced to rise slightly by the disconnect as the trigger is released.

It isn’t possible to cover every type of aftermarket rifle trigger but the main ones operate on the same principle. Do your research and get it right. AG