Building an AR-Style Rifle from a Gun Kit? These Are Some of the Most Practical Upgrades to an AR15 Kit

Building an AR15 or an AR-style platform from a gun kit? Most AR15 kits come with everything you need to assemble a fully-functional rifle, minus the lower receiver.

Many parts kits come with standard parts or mil-spec parts. While this might sound like a good thing, for some shooters, mil-spec parts just don’t cut it.

One misconception is that “mil-spec” is synonymous with “better.” This is not the case. Mil-spec just means it meets military specifications; other aftermarket parts may be far superior in terms of performance.

So, if you’re building an AR15 from a kit and are looking for parts to upgrade that will improve performance, these are some of the most practical.

Bolt Carrier Group Upgrades

If your AR15 kit comes with a bolt carrier group (not all of them do) and it’s a mil-spec BCG, it’s probably going to be phosphate coated.

Phosphate-coated BCGs are good enough. They’re matte (which makes them non-reflective and is good for concealment) and they’re fairly low maintenance. Phosphate-coated parts are also fairly easy to maintain and resist corrosion and wear.

But they are not the best in terms of permanent dry lubricity and resistance to moisture and corrosion. There are a wide range of more modern coatings, including nickel boron, titanium nitride, and black nitride, all of which offer superior performance.

All of these coatings (though expensive compared to phosphate) are extremely hard, wear, water, and corrosion resistant, and all of them exhibit superior permanent dry lubricity.

This means they require less liquid lubrication (which traps dust and dirt), making them easier to clean and maintain, overall.

Muzzle Devices

Muzzle devices are another impactful upgrade you can make to an AR gun kit. Some kits come with them, many don’t. If your kit comes with one, it’s probably a flash hider.

Flash hiders, which conceal your muzzle flash, can be useful in combat situations, as they can keep your position hidden. Other than that, they look cool but don’t offer much use.

There are two other classes of muzzle devices that offer much more practicality for the majority of civilian shooters: muzzle brakes and suppressors.

Suppressors, also known informally as silencers, trap some of the expanding gases at the muzzle before they exit the barrel, substantially diminishing muzzle report. They are NFA items, though so be aware of them.

The other one is a muzzle brake. At first sight, you might confuse a muzzle brake and flash hider, because they often look very similar, but the function of these muzzle devices is fairly different.

While flash hiders conceal a muzzle flash, muzzle brakes change the manner in which gases are ported around the muzzle. This helps redirects some of the force of recoil, which helps mitigate felt recoil and muzzle flip.

This, in turn helps keep your sights on target, enabling faster, more accurate follow-up shots.

(Note: regardless of barrel length, if your barrel is threaded and you don’t want to isntall one of these muzzle devices, it’s a good idea to get a thread protector and use that instead as barrel threads are very suspect to damage.)

Buffer Weights

While you can change felt recoil by adjusting the gas system (not necessarily recommended unless you are having problems with feeding/ejection) or by installing a muzzle device like a brake, you can also make an impact on felt recoil by tuning the buffer system.

An AR-15 rifle’s standard buffer weight is between 2.9 and 3.0 ounces. However, some builders prefer to up the weight to a heavy, or H2 buffer, which weighs 3.8 ounces.

This nearly full-extra ounce, when added to the buffer system, substantially increases the reciprocating mass of the rifle.

Most importantly, it enables you to cut felt recoil substantially without having to adjust the gas system or install a muzzle device. If you feel as though your rifle kicks a bit sharply for your liking, one of the simplest things you can do to adjust this is up the buffer weight.

Trigger Upgrades

Mil-spec AR-15 triggers that come with some gun kits are passable, but other shooters don’t prefer them and some even consider them gritty.

If you’re looking for an upgrade, there are tons of AR-15 compatible trigger units out there and many are drop-in ready without requiring you to take a trip to the gunsmith.

Consider TriggerTech Triggers, which are the only triggers on the market that don’t require sliding friction to operate, delivering an extremely crisp experience and a short reset.

Plus, if you upgrade your AR’s trigger, you can keep the trigger unit that came with the gun kit as a backup in case you ever need to replace it.

Handguard Upgrades

If your build kit came with one of those polymer handguards with aluminum heat shields that are commonly found on M16 rifles, it wouldn’t be too surprising if you end up looking for something better.

They are serviceable but lack attachment points and trap heat around the barrel anyway. Some AR-15 rifle kits come with upper receivers and handguards with mil-spec quad rails; others don’t.

Consider an M-LOK or KeyMod handguard as a replacement for a Pic rail or a plain handguard without attachment points. These are lighter and just as strong as Pic rails and offer greater flexibility with respect to mounting shooting attachments.

Another quick upgrade you could make to your AR-15 kit is to get a vert grip and install that at the bottom of the handguard; these can improve handling and are low-cost and easy to install.

High-Quality Gun Kits

In addition to AR 15 kits, we offer a wide range of gun kits including pistol build kits that are perfect for completing your own platform at home, and customizing it during the process.

We also carry thousands of gun parts in our online shop and in our showroom in Easton, Pennsylvania. Take a look through what we have listed online and if you’re looking for something specific for your build, get in touch with us at 610-250-3960.