New AR-15 Triggers

I am presently working on anew book project. It is quite challenging but very rewarding at the same time. This new book on rifles, marksmanship, and personal defense is years in the making. I have had the opportunity to test and evaluate quite a few AR-15 rifles. Inevitably, the rifles come up short, to my standard, in one way or the other as they are pushed to the highest degree. The rifles are reliable, in the best versions, and the Colt, Ruger, CORE, and Smith and Wesson rifles have given good results overall.

One area that has been less than ideal for accuracy work is the trigger. Of those tested, the average was around six pounds. I was not surprised. I recently tested HK-type .308 rifles with triggers as much as nine pounds! This isn’t ideal for good accuracy. The AR-15 rifle’s trigger action was designed for durability and ruggedness, not precision. The rifle may be hot or dirty but the trigger will reset.

The action is suited to a military rifle with full auto capability but accuracy potential cannot be fully realized with the standard unit. While some triggers may be managed well enough from a solid benchrest, from position (especially offhand) hits are more difficult. For this reason, I have replaced many triggers over the years. How AR-15 Triggers Work Standard AR-15 triggers have a front that lies in a notch in the hammer to remain a full cock. There is no intermediate sear.

The disconnect and spring ride inside of the trigger, and the disconnect hook is located at the rear of the hammer. With the safety applied, the rear of the trigger cannot rise. When moved to "fire", the safety clears the trigger. When the trigger is pressed, the trigger moves from its slot in the hammer and the hammer falls. After the rifle fires the bolt carrier recoils and cocks the hammer. With the trigger still depressed, the disconnect hook grasps the disconnect.

Releasing the trigger releases the hammer from that hook, giving a characteristic click as the trigger resets. If modified or worn, the disconnect tips too much to the rear and the rifle may fire when the trigger is pressed and again when the trigger is released for reset. If the disconnect fails the rifle may not fire at all as the hammer will ride down with the bolt without firing the rifle. AR-15s for civilians are more akin to a Designated Marksman Rifle than the short barrel full-auto used by the military.

Repeatability and reliability is paramount, with a smooth trigger action and rapid reset. Most of us prefer a smooth trigger to a light trigger but both lighter than standard and smooth is good to have. For a service rifle the action must be reliable with all

They are well made of good material. types of ammunition. This means a standard hammer fall. A trigger action with low forces at the trigger may not always equal a heavy hammer fall, so a balance is needed. Hiper Fire Hiper Touch While factory AR-15 triggers are heavier than we like for precision use, they do have a fast reset. After some study I chose the Hiper Touch EDT 3 duty trigger (HiperFire.com, for use in one of my AR-15 rifles.

This rifle was a reliable performer but had left the factory with a nine-pound trigger. I wouldn’t lighten a factory action by polishing and removing metal in such triggers because exposing the softer material of the hammer and trigger could lead to big trouble. A quality The Hiper Fire trigger was delivered with two spring sets. One is for a trigger pull weight of four pounds plus and the other six pounds plus.

What drew me to the design is the geometry of the trigger and hammer allow a light let off while the hammer fall is as heavy as mil spec despite the lighter pull. Other advantages of the trigger are discernible under magnification. The Hiper Fire trigger has slots running the length of its bottom so the disconnect will move debris (unburned powder and other particles) from the trigger to prevent jamming.

The underside of the trigger has been raised and the end ramped up to increase the clearance between the trigger and the lower replacement is demanded. Initial examination of the Hiper Fire trigger showed a good design with excellent fit and finish. The surface was well finished and the parts seem well fitted. fire control cavity. According to Hiper Fire, this will help prevent a blown primer cup or other debris from jamming the trigger. The trigger installed with a minimum of work.

Hiper Fire recommends a 200-cycle dry fire break in. The trigger was delivered lubricated and I performed this

This is a good fit and trigger action. break-in without problem. To install, clear the rifle, then break the action open and remove the upper assembly. Never allow the hammer to fall on the bolt catch as you can crack the lower receiver. The lower receiver should be stabilized in a vise or block. Drive out the pins holding the trigger and hammer. Remove the trigger action. Assemble the Hiper Fire trigger assembly. Place each side of the spring on the shoulder of the trigger.

When the trigger goes into the receiver, the legs of the spring must be curved under the trigger and facing toward the front of the lower receiver. The disconnect spring will ride in the trigger in the circular cutout. The larger end of the disconnect spring is down in This is a big plus. the trigger and the smaller tip is facing upward. A punch may be used to push this down properly. The disconnect rides the top of the disconnect spring so that the holes in the side line up with holes in the trigger.

When pressing the trigger pin in to secure the trigger action, be certain it is flush with each side of the receiver. Also, when ordering, be certain to order the correct parts. The Colt AR-15 takes a different trigger pin. I tested a Smith & Wesson M&P 15 fitted with a Hiper Fire trigger extensively with good results. The intrinsic accuracy of the rifle isn’t affected but the practical accuracy is.

Using a Burris AR-F3 red dot optic and new trigger, I was able to better my groups by a quarter inch at 50 yards using Creedmoor 75 grain HPBT ammunition. The primary improvement was in rapid offhand fire. A magazine full of a steel cased load was dirtier and much less accurate than the match grade load, but the hammer cracked the primers, which is all we may ask. Ruger Trigger Ruger surprised me by offering a high quality drop-in trigger for their AR 556 series.

While well suited to any AR-15 rifle, the Ruger uses small pins (0.154 inch) so this won’t fit the Colt. The Ruger Elite 452 MSR is a twostage trigger designed for all Modern Sporting Rifles with 0.154" pins, this unit is delivered with a press weight of 4.5 pounds according to Ruger. My example breaks 4.6 pounds so we are on the money, and it should smooth in with use. I have used the Ruger extensively in testing and in the world of seven hundred dollar AR-15 rifles, the Ruger is the one to beat.

The rifle is delivered with sights, and the forward assist and dust cover are intact. The easily removable handguard and serrated front sight ramp are other advantages.

I carefully examined the Ruger trigger to verify that the hammer is full strength and acceptable for critical use. The 452 MSR uses a lightweight hammer to retain a full hammer strike. To verify reliability, I use handloads with CCI Rifle Primers as they’re traditionally hard. When using a rifle with a floating firing pin, a hard primer is a good thing. Resistance to high pressure is also good. I also added a number of steel cased loads in order to quality reliability.

The Ruger 452 MSR is supplied with a safety selector and the springs and pins for installation. I was impressed that the trigger is delivered in a polymer approximation of the AR-15 firing handle. This makes for easy acclimation and dry fire before installation. I am certain this assembly will be found in well-stocked shops and allow shooters to decide if they wish to install the lighter trigger in their personal rifle. Ruger’s trigger was easily installed—no surprises there.

While it would be suitable for any AR-15 with small pins, the Ruger AR 556 was the subject of this test. The trigger settled into 4.5 pounds after a bit of dry fire. The rifle was test fired with a variety of handloads using the CCI rifle primer and also some steel-cased loads that I have not enjoyed the best service with. However, it was all bang-bang with good reliability. Firing at 50 yards for accuracy with the accurate Creedmoor load produced good results.

Both of these trigger actions are relatively new and have passed the road test. They are good kit, well worth their price. When installing, place the lower receiver in a fixture and insert the disconnect spring with the flared side down. Be certain the spring legs of the new trigger rest on top of the receiver’s lower interior, not the cut out for the trigger. Be certain of disconnect orientation.

With the trigger in place install the hammer spring legs across the top of the trigger pin and cock the hammer into place. AG American Gunsmith Reader Services 1.