Fixed vs. Variable Scope for Your AR-15, What Do You Prefer?

Fixed vs Magnification Scope for AR 15

Choosing the best rifle scope for your AR-15 can be challenging especially if you’re new to scopes. There are hundreds of scope options on the market leaving you with a huge decision to make. Do I go with a variable or fixed scope? These are some of the questions to ask as you look forward to selecting an ideal scope for your AR rifle. The fixed and variable scopes are the two types of scopes in the market.

Before we even get to decide the best scope for an AR-15, let find out the differences between these two types of scopes.

Fixed Scopes


A fixed scope just as the name suggests uses a specific power that cannot be changed. They have no adjustment on the magnification. This provides them with the benefits of being less complicated, lighter, compact and cheap. They are highly portable, easy to carry something that makes them a great pick for beginners.

However, fixed scopes lack flexibility when it comes to setting the right magnification. They might not be an ideal pick when you need to use different magnifications.

Variable Scopes


These are scopes tailored with variable magnification powers to suit different situations when shooting or hunting. One of the most significant benefits of the variable scope is being able to tailor the amount of magnification to the target at hand. You can adjust to maximum magnification to spot targets at long distances before narrowing down the magnification for a precise shoot.

However, they come with their disadvantages. They are usually bulky and heavier making transportation in the field an issue. They also require parallax adjustment and are usually hard to site in.

So, What Type of Scope’s the Best Choice for Your AR-15?

In general, the only difference between a fixed and variable scope is the settings on their magnifications. The AR-15 is one of the most versatile rifles to use and one that will require a robust scope. The choice between a Fixed and a Variable Scope for Your AR-15 will still come down to the exact use of the scope. A fixed scope can work well for sports purposes where you have to shoot at close ranges. However, the most versatile scope for an AR-15 is the variable scope which gives you good speed up close and great precision when shooting at long ranges.

For long range shooting, you need variable long range scope to gain more shooting capabilities. You can easily nail down targets from distances of 600 yards using variable long range scope as compared to fixed scopes.

The variable scope might have the weight drawback, but that will not be a major concern when you consider the versatility they give your AR-15. They also come with a variety of features which enable different users to achieve their goals. The target game is also crucial in determining magnification as opposed to range. There is a misconception that range usually determines magnification when hunting small game. Hunting a squirrel at 100 yards will require the same magnification as a deer 600 yards.

This is where our variable scope comes in with the primary benefit of collecting information first. A variable scope on your AR-15 when hunting can collect information at very high magnifications. Once you have the target on site, you can then lower the magnification to engage targets easily.

Final Verdict

For the AR enthusiasts, choosing a variable scope for your AR-15 comes with plenty of benefits. Think about your needs carefully and choose a model that matches them. Navigating the variable scope might be the hard. However, it is not as hard as navigating your AR-15 rifle. While a fixed scope is also excellent, it is not the best when handling a versatile rifle like the AR-15. It does not offer AR-15 users the much-needed flexibilities when shooting. Flexibility to play with your magnification to get the target at close and long range is only possible with a flexible scope.

The Millett DMS-1 Optic For Your AR-15

The Millett DMS-1

The Millett DMS-1 has recently jumped onto the market as an excellent value for those looking for a variable low power scope. DMS stands for “Designated Marksman Scope”.

In an effort to find something with more versatility than the ACOG or the Aimpoint, I decided to try out the DMS-1. As an optic that adjusts from 1-4x, with a battery illuminated “dot in donut” reticle, this optic showed some promise from the start.

With the magnifiers for Aimpoints and such, you can see why something like this needed to come about.

Millett DMS-1 with 30mm LaRue Tactical SPR-S mount

Add in the price tag (just a little over $200 at most places) and you have a very tempting scope for many of us in the world of AR15 rifles.

Knowing that an optic is only as good at it’s mount, I chose the best mount on the market for such a purpose, the LaRue Tactical SPR-S mount. LaRue stands above them all in almost every category of mount or railed handguard. They are also known for excellent customer service as well as quality.

This top notch quality and customer service comes at a price though. The mount cost almost as much as the optic.

Still, for a quality optic/mount combo coming in at around the $400 mark, I have no complaints.

Custom 20″ AR15 build with Millett DMS-1

I decided to mount the scope on my custom built 20″ AR15. It features a 20″ Colt govt profile 1/7 twist chrome lined barrel. It also features a Hiperform free floated carbon fiber handguard and a 2-stage trigger. I’ve shot 1″ groups with it at 100 yards in the past so I know it is capable of respectable accuracy.

I could do a couple more things to squeeze out every last bit of precision from the gun (mostly by upgrading the barrel), but I am quite happy with it as is. Mostly because I prize lightweight and durability in a combat rifle.

I took it out for testing a couple times to see how it would do and can say that at this point so far I am pleased. I also had a few others inspect, test out and try the scope and they were all impressed with the clarity and function of the scope.

3 shot group, 1 inch boxes

In my accuracy testing I shot the above group from 50 yards with 75gr Prvi Partizan Match ammo. It was a fairly windy day (about 10 mph winds) but I believe any lack of precision should be blamed on me, not the wind, optics, or the weapon, as I am no sniper.

However, I was happy with the group for my purposes.

My conclusion is that this is a very good optic for the money. If I had one issue, it would be that I wish it had more eye relief.

I really like the precision of the dot with the quick acquisition of the “donut”.

I saw little need for the reticle to be illuminated during day time shooting as it was much like a regular scope.

I don’t think it really does either job better than the ACOG (4x) or the Aimpoint (1x), but it is a good compromise and goes extremely well on this particular rifle. I don’t like the idea of a dedicated long range AR15 because I believe that the most likely combat scenarios for a normal citizen (and even most LE and maybe even military) is going to be under 100 yards.

Even though this is my “long range” AR15, it is still fairly useful at close range because I can use the scope at 1 power.

Only time will tell how well it holds up, but I am optimistic.

Which Caliber for your AR15 Carbine?


A large part of this is subjective. You may have particular criteria you want/need your AR15 carbine to meet, you may or may not reload your own ammo, etc… You may even have several AR15’s in a variety of calibers.

That said, of all of the various calibers out there for the AR15, I prefer the 5.56. There are several reasons for this. For one, 5.56 is plentiful and easy to get a hold of and much of it is made domestically. If for any reason, production and shipment of ammo from foreign countries were to cease certain cartridges would lose a lot of appeal and would suddenly cost MUCH more than currently.

Also, it is fairly inexpensive, when compared to most other rifle rounds. This means you can shoot more often and stash more of it. I believe that shot placement is paramount. The best way to improve that is through shooting. 5.56 costs less to shoot than many other calibers.

The 5.56 round is an underrated round in my opinion. No, it’s no death ray, but it is effective when placed in the right spot. The light round allows you to carry a lot of ammo. Light recoil allows for fast follow up shots. It is also a very flat shooting round.

Most of the various AR15 calibers are not nearly as common. Most are impractical, but the biggest reason to avoid them is because of parts availability for AR15’s in those calibers. If your primary defensive carbine is in another caliber such as 6.8, I recommend you keep plenty of spare parts/magazines and get into reloading.

.223Rem and 5.56 ammo have the same case dimensions on the outside but 5.56 is generally loaded to higher pressures. Therefore, you can safely shoot .223Rem ammo in your .223Rem or 5.56 chamber. I wouldn’t attempt to shoot 5.56 in a .223Rem chamber though. It could be dangerous.

However, not many AR15’s are even made with a .223Rem chamber. Still, steer clear of a .223Rem chamber in a tactical carbine if you come across one.

The .223Wylde chamber was created as a bit of a hybrid chamber that could also shoot both .223Rem and 5.56, and do so more accurately than a 5.56 chamber.

Shooting .223Rem in a .223Rem chamber will slightly increase the accuracy and velocity of the .223Rem round as opposed to shooting it in a 5.56 chamber. The .223Wylde bridges this gap just a little bit better for both cartridges.

It should be noted that the barrel will indicate which caliber your AR15 is chambered in. If your barrel says “5.56” and your receiver says “.223”, your AR15 is chambered in 5.56.

Superlight AR15


When I first started into the AR15 world, I had a strange desire to get an HBAR (Heavy Barrel). When I finally got myself one, I quickly saw the downside to it and learned why I didn’t want one anymore. All it took was a few outings with the HBAR. It was pure misery.

I had also come to realize that the AR15 was originally designed to be lightweight. The original 20″ AR15 sporters sold by Colt weighed in at around 7.6lbs loaded. The AR15 was never meant to be a machine gun or a sniper rifle originally.

M4 vs. Superlight

M4 Profile Barrel (Top) vs. Superlight Barrel Profile (bottom)

Superlight barrel carbines point vert fast and balance the weapon much better than heavier AR15 barrels. Although many people who advocate HBAR’s are quick to point out that thinner barrels heat up much faster, they tend to forget that they also cool down much faster.

Yes, you lose some accuracy, but not the practical kind in short-lived defensive shootouts.

I’ve gone through carbine classes where people’s superlights (many LEO’s) have held up just fine through all of the shooting drills even though we were putting a lot of rounds downrange quickly. I’m convinced that the superlight barrels are just fine for any likely scenario one might encounter as a civilian or an LEO.

My Superlight AR15 (bottom) in it’s original configuration

This particular carbine that I built was inspired by a rifle my brother had built with a chrome lined superlight “pencil” barrel and a carbon fiber free floated handguard. This is the same guy that told me not to get the HBAR in the first place. However, some of us have to experience things the hard way before we learn…

We had done several builds (for me and helping others) and had so many leftover parts from past builds that I practically had enough to build another complete rifle. This happens as most AR15’s we built were upgraded and utilize other various parts, leaving various extra parts. All I really needed was a barrel and the lower receiver.

I have since upgraded and changed out certain parts, including the buttstock, handguards (now DPMS carbon fiber free floated), and from an A2 fixed carry handle upper to a flat top upper with a cut down detachable carry handle.

Superlight AR15 build

With a loaded 30 round magazine, this 16″ superlight weighs in at 7.5lbs

It may not even have finished it’s full transformation. I might even try to lighten it up even more with a Cavalry Arms complete AR15 lower, which I estimate may drop close to 1lbs from the total weight.

Although it is mine, I built this one with my wife in mind. She shoots it very well too. At one point I had considered getting her an M1 Carbine, but the Superlight AR15 is very light. On top of that, it shoots a better round that I already own, shoot, and reload for, and it has parts that are compatible with my other AR15 rifles.

It’s a light and handy carbine that I can trust with my life and the life of my loved ones.