In the previous chapters we covered the workings of a single and 2 stage trigger for AR-15 style rifles. I will bring it all to together in this last chapter.
To begin with, you need to determine how you are going to use your AR-15. Are you looking for a 3 gun / speed gun? A long range target heavy barrel open target rifle? Will you only use it for national match, high power competition? Are you looking for a rifle that will be an all around fun rifle to shoot with accuracy at the range with your family? Once you know that you can start to pick out the base rifle or the parts you need.
If you want a 3 gun only rifle, you’ll want a single stage trigger with very low trigger pull weight. This will give you a very fast trigger and work well for this type of shooting. If the rifle will only be used this way, OK. But keep in mind that triggers that are super light with very short resets are not safe for inexperienced shooters. You’re asking for trouble if you hand that rifle to a young son or daughter or your spouse without much shooting experience. Anything below 2.5 pounds of pull is starting to get too touchy for the average shooter. Some of the speed triggers are less than 1 pound. Many instructors won’t let you use a rifle set up that way in a defense or tactical class. If you want a speed gun, great. But please only use it in competition and at a controlled range. Remember safety first. You don’t get a second chance at firearms safety.
For a long range target rifle that will not have to meet a minimum pull weight, a 2 stage trigger is a must. Look for one that is adjustable. If this will be a long range bench rest gun, drop the pull weight down to what feels good to you. But remember all the safety issues you get with super light triggers. If this is only a bench rest gun, great. If you think you’re going hunting or plan to shoot off hand at some point, don’t do it. Light trigger pulls are not safe when out of a controlled environment. I’m sorry for repeating myself. Remember safety first. You don’t get a second chance at firearms safety.
There is good news for you super light trigger people. An AR-15 has only 2 pins holding the lower receiver to the upper receiver. Buy yourself a second lower and put in a trigger with more pull if you want to take it out of the competition environment. Put on the same stock and pin your competition upper to the lower and you’er set. You can now go out to the range with a much safer gun and still get the feel of your competition rifle. Don’t forget, higher pull weight is still not an excuse for poor firearm safety.
If national match type shooting will be the main use of your rifle, the 2 stage trigger is for you. You’ll want one that is reliable, smooth, adjustable and with a crisp break. Let’s look at your needs one at a time.
Reliability. You want a trigger that will not fall apart in the middle of a match. You want a trigger that will not go out of adjustment in the middle of a match. I will explain more about adjustment later. A big part of reliability is the heat treating. Heat treating done wrong will cause the hammers to crack and then snap in two.
Smoothness. You need to buy quality. Mass produced triggers will not get you there. Good triggers are machined well, great triggers are machined perfectly, then hand test fit individually.
Adjustability. Without an adjustable disconnector you’ve lost before the match even starts. Other adjustments like overtravel and second stage pull weight are also very important. The overtravel adjustment will allow you to get the feel you want and smooth out your pull. With adjustable second stage weight you can fine tune the trigger pull to your preference. First stage is adjustable on all triggers that are not a sealed drop in. Just bend the trigger spring legs to increase the pull. You can look at our instillation instructions to see how it is done.
One of the important parts of adjustability to take a look at is how is the adjustment done. On some triggers, a patched thread is used. A patch is a small piece of nylon pressed into the thread of a fastener. The patch will hold a screw or nut in place. Using them is fine in the proper place, but some manufactures use them in high stress points like a disconnector adjuster and they will not hold. The best way to hold adjustment in a high stress location is to use Loctite. Yes. Loctite is not as easy as turning a screw but it holds and holds for a very long time.
You also need to look at were the adjustment takes place. The placement of the adjuster is important. Putting it in the wrong spot can weaken the hammer or trigger body. The point that the adjuster stops at is also important. Adjusters that stop on aluminum will wear and feel soft when they stop. Adjusters that stop on steel will not wear and will have a very positive stop.
Crisp release. This is one of the most important things to look for. A well-made trigger with a bad release is next to useless. Unfortunately you can’t see the release of a trigger. You need to feel it for yourself. So do some research, ask around to see just who is winning matches and who is complaining about creep and pull through.
The good news is a match AR-15 must have a pull weight of no less then 4.5 pounds to pass inspection.
This means your rifle has a relatively safe pull weight. But remember a heaver trigger pull is no substitute for safety. Your rifle my be a bit heavy for inexperienced shooters so keep this in mind when you’re at the range and you let someone shoot it. You can pin a new light barreled upper on your lower and pull the stock weights out in short time. Now you have a lighter rifle but still have the national match trigger for novices shooters to get a feel for. You’re also saving wear and tear on your high dollar upper. I’m sorry to repeat myself again but, please follow all the safe firearms handling rules at all times.
For an AR-15 that is good for most all situations, I would stick with a 2 stage trigger. For one thing, they are more accurate then a single stage. If you plan on doing some hunting you’ll have the accuracy at longer ranges to make the shot. With the 2 stages you can teach a new shooter to slow down and get a good site picture before pulling the trigger. You don’t need adjustable overtravel. But if you get it, it won’t hurt. You should still get an adjustable disconnector to keep the creep out of your trigger. This makes the pull so much more predictable, I can’t imagine shooting a rifle without it.
I promise this is the last sales pitch in this set of posts. How does the M-K line of trigger stack up and meet the needs of shooters?
Speed. Our M-K IIA2 and M-K IIA3 models have a shortened reset which gives them good speed for a 2 stage trigger. We can’t compete with a 1 pound single stage trigger for speed but they can’t compete with our release. And they are not in the same league with us for accuracy.
The M-K X I will admit is a slow trigger. It has a long reset and a long first stage. That’s what you get when you have the best release possible. This is a pure accuracy trigger and was designed to be the best in the world.
Reliability. All M-K trigger are heat treated to our specs. Sorry, it’s a secret. Our hammers just do not break. I had to crack one in half for a test one time. We locked it in a vice and hit it with a hammer. Nothing happened so I hit it harder. I mean really hard. It snapped with a crack and sent the top half of the hammer across the shop into the windshield of the shop truck.
Adjustability. All M-K trigger have adjustable disconnectors. They are all zero creep triggers. They all come with multiple second stage springs and a preload plug in the bottom of the trigger body to fine tune the second stage pull weight.
The M-K IIA3 and the M-K X have adjustable overtravel. They use a proprietary safety selector with the adjusting screw built in. The adjusting screw is stopped by hitting the floor of the trigger. This way you have steel on steel for your stop. The selector can also be installed from the left or right side of the receiver, to accommodate left or right handed shooters. The selector has just one switch lever, unlike most ambidextrous safeties that use two. With just one you don’t have the unneeded switch lever messing up your grip.
Smoothness. M-K trigger pin holes are hand-honed. All M-K trigger and hammer hooks are machined to extreme surface tolerances. This gives the shooter a smooth feel (No Grit) through the entire trigger pull.
The Break. M-K triggers have been known for the finest break on the market since Charlie invented them. I could go on trying to explain the feel all day long. But you need to try one to get the experience of what a true national match trigger should feel like. Ask the shooter that has one, or stop in our shop. I’ll be happy to let you try some.
I think that’s about all for now. I’m sure something will pop in to my head that I forgot about so keep looking for updates.