A friend at work has recently expressed an interest in buying a semi-automatic rifle, likely an AR-15. I started jotting down what considerations he should ponder and decided to do a full write up in a post here so it can be easily referenced later. So here we go!
The primary consideration when choosing a rifle is the use case. What purpose is the rifle for? There are many options and it is entirely up to the purchaser to decide them. Perhaps they include target shooting, competition, training or skill building, hunting or a variety of other options. Considering what one wants to do with a rifle is the foremost consideration and will drive the following choices.
Once you have decided on the use case, I think the next important decision is the sights. Will the rifle be used with iron sights only? A red dot sight? A magnified optic (traditionally called a scope)? Making that choice first will help narrow down options for the top end configuration. A red dot sight and iron sights can be easily included on the same rifle. Choosing a rifle with iron sights and a magnified optic reduces choices, but can be done. The primary use of the rifle will help drive what sort of sight or sights will be chosen. For keeping it affordable, iron sights are king.
If this is your first AR platform rifle and you don't have a specific use in mind, I suggest a low powered magnified optic with an illuminated reticle. This allows for fast shots like a red dot and lets the user crank up the magnification for target shooting. There are some decent options today for around $200, which isn't that much more than a basic red dot sight.
Next to choose is caliber. The AR-15 is commonly available in more cartridges than ever. In addition to the traditional 5.56 nato / .223 Remington, we can find lots of options chambered in:
300 Blackout
9mm
6.5 Grendel
6.8 SPC
7.62x39
450 Bushmaster
There are of course other options, but these are the most common options, options for which there is both a multi-year history of use and a half dozen or more manufacturers that make parts for them. Some of these use standard AR-15 parts, some do not. This chart shows whether each caliber uses standard AR-15 bolts, magazines and buffers. In general standard configuration parts are more affordable.
| Cartridge | Standard Buffer | Standard Bolt | Standard Magazine |
|---|---|---|---|
| 300 Blackout | Yes | Yes | Yes |
| 9mm | No | No | No |
| 6.5 Grendel | Yes | No | No |
| 6.8 SPC | Yes | No | No |
| 7.62x39 | Yes | No | No |
| 450 Bushmaster | Yes | No | Yes |
For a first rifle I recommend 5.56 for a general use rifle. It is the most common, most reliable and most affordable overall. A rifle chambered in 5.56 can also shoot .223, where a rifle chambered in .223 should not shoot 5.56. If a person wants something a little more versatile, consider 300 Blackout. I would only recommend one of the other options if your use case demands something with those capabilities, like medium game hunting. If you want your rifle to be useful for something like deer hunting, then consider 6.5 Grendel, 6.8 SPC, 7.62x39 or 450 Bushmaster. 9mm is handy for indoor practice, because it is much quieter than the other rounds, or for shooting a lot because the ammo is the cheapest, but outside of that, I wouldn't recommend it for a first or only AR rifle.
The last important choice to make is the barrel type and length. Again, this should be dictated by your use case. Long range target shooting? Pick a heavy stainless barrel, maybe something a little longer. Longer barrels offer more velocity and less muzzle blast, with the tradeoff of being heavier. Plan to use the rifle to take tactical classes where you are moving a lot and shooting 600 rounds in a weekend? A 16" chrome lined barrel is a good choice. You also want to consider twist rate, which is dependant on caliber and usage. For 5.56, 1:7, 1:8 or 1:9 twist will serve most people for most purposes.
As part of the barrel we should consider the gas block. You have two basic choices, a gas block with a built in front sight or a low profile gas block. If you are going to run a rifle with a front sight, choosing a barrel with a front sight gas block saves you trouble later on. If you plan to run a magnified optic or scope, then a low profile gas block that sits under the handguard will be a better choice. Once you have those choices settled, you can start shopping for options.
Once you have some basic options decided, you can look to the other options. Any of these are easy to change out later if you decide to, the AR-15 is quite modular. You can swap a adjustable stock in a minute, or a grip in 5 minutes. Handguards are relatively easy to change, as are muzzle devices like a flash hider or compensator.
A basic handguard works fine for many applications and if you want to add attachments later you can swap it out for a Magpul MOE handguard for $35 or so. Or lots of affordable rifles come equipped with a MOE handguard right off. If you plan to mount optics forward of the reciever or want to squeeze the most accuracy out of your barrel, a free-float handguard is a good choice, but will cost extra. This can be changed out later, but depending on the rifle configuration may take a bit of effort. You can find free floating handguards that are designed for stock gas block sights or for low profile gas blocks.
The standard A2 flash hider works fine. There are devices that are better at being a flash hider or you can run a compensator. I would recommend against a compensator if you plan to use the rifle indoors. As mentioned, this is easy to change out later on, so there is no need to worry much about what the rifle comes with at first.
There are a dozen different choices in grips, so you can either find a rifle that has one you like or spend $20 - $30 later on to change it.
There are 20 or more options for stocks. The standard collapsing (adjustable) stock works fine, or you can spend $40 or $100 or $300 on a stock that offers extra features or comfort. Stocks change out quite easy.
Lastly I'm going to offer some options for rifles for different purposes.
First up- A basic rifle. Start with a basic Ruger, Smith&Wesson, Diamondback AR-15 with a 16" barrel chambered in 5.56. Or pick another reputable brand. (if you have a question about a given brand, please ask in the comments and I will respond) For around $600 you can find a new model with a fixed front sight, a folding rear sight (so you can flip it down if you run a red dot sight) and basic furniture. For not much more you can get into a rifle with a free float handguard, but keep in mind you will need to add a front sight to many of those models if you want to use iron sights. Buy some ammo, a few magazines and a sling and you are set.
Next option- a target or hunting rifle. We will start with a 18" Diamonback or PSA in 6.5 Grendel. Both come with free float handguards for each attachment of a bipod or other accessory. Put a variable power scope on it, like a Burris 1 - 4 power or a Primary Arms 1 - 6 power or something similar. You get low light capabilities with the illumination and some magnification for target identification when hunting or target shooting. Get some affordable steel case 6.5 Grendel ammo for practice and some high quality ammo for hunting or long range shooting and you are set.
Of course you can spend big money on a Noveske, Daniel Defense or BCM rifle if you want top quality, but in my experience the lower tier rifles today are reliable and accurate enough for most uses. You can find a AR-15 with a 24" stainless bull barrel for tack driving accuracy, or a 14.7" lightweight barrel with a welded on flash hider (to get it to the legal 16") for a ultra-light setup. You can run a $600 Aimpoint red dot that you can drive a truck over or a high end Zeiss scope scope to count the hairs on a spider's leg at 100 yards. Furniture (the stock, grip and handguard) are available in various colors. There are literally hundreds of options.
The good news is the platform is very modular and it's easy to change many things out later on. Please feel free to ask any questions you may have in the comments and I will answer to the best of my ability.
If you would like my thoughts on choosing a AR-15 for deer hunting, you can read that here.
https://steemit.com/hunting/@pistolpete/deer-hunting-with-an-ar-15
https://steemit.com/hunting/@pistolpete/deer-hunting-with-an-ar-15-part-2