Rifle Roundup: APF AR-15 In .300 BLK With A Lucid Optics P8 Sight

.300 Blackout works great with a suppressor, so we're teaming this rifle up with one from SIG Sauer.

posted on June 30, 2023

This week on Rifle Roundup, it’s an APF Guardian AR-15 in 300 Blackout, along with a Lucid Optics P8 4x sight and a SIG Sauer suppressor.

The AR15 is a versatile platform that, with a few modifications, can shoot a number of different calibers. If you’re looking to shoot something other than the ubiquitous .223 Rem. and 5.56 rounds, one of the easiest to use is the .300 Blackout cartridge. .300 Blackout (or .300BLK for short) uses the same bolt face as .223 Rem./5.56, which means all you need to do in order to .300BLK in your AR is swap out the barrel (and probably your magazine followers) and you’re ready to go. However, rather than change barrels and re-zero your sights every time you switch from .300BLK to 5.56 (or back), it’s a lot easier to buy or build a dedicated .300BLK upper or AR-15, saving you the time and energy of swapping out a barrel on your AR when you want to change calibers.

The question then becomes, why choose .300BLK over .223 Rem. or 5.56? The answer to this question for me isn’t either .223 Rem./5.56 or .300BLK, it’s both. Each of these cartridges has a role to play, and both play it very well. The lower cost of .223 Rem. and 5.56 ammunition make it ideal for training, practice and trips to the range. .223 Rem./5.56 is also more accurate than .300BLK at more than 300 yards, so they are a better choice when you need to reach out and touch something. However, practically all .223 Rem./5.56 ammunition is supersonic, which means that it makes a loud “Crack!” as it flies downrange, reducing the effectiveness of a suppressor.

.300BLK, on the other hand, was designed from the ground up to be suppressed, and also works well with shorter barrels. A supersonic .300BLK round also has slightly more muzzle energy than a typical .223 Rem./5.56 round, making them a good choice for hunting medium-sized game such as feral hogs. However, .300BLK isn’t made in the same quantities as either .223 Rem. or 5.56, which means you’re going to pay a bit more for your ammo than those other calibers. With that being said, let’s look at the rifle we’re featuring today, the APF Guardian, which we’ve closed to shoot in .300BLK.

Rifle: .300BLK APF Guardian

APF is one of the hidden gems of the AR world. They make excellent AR pattern rifles, including AR-15s, AR-10s and even AR-style rifles chambered in heavy-hitting calibers like .300 Win Mag and .30 Nosler. The Guardian is their base model with a free-floated 16 inch barrel, a 15 inch slimline M-Lok handguard and an M-16 style bolt carrier group. The Guardian also has an M4 pattern adjustable stock, A2-style grip and a “birdcage” flash hider, which I removed so I could add the quick disconnect for my SIG Sauer suppressor (more on that later).

One of the things I like about APF rifles is all the Cerakote options they have available for their guns. Whatever color scheme you can dream up for your AR, chances are, APF can make it real.

A firearm chambered in .300BLK can use a standard pattern AR-15 magazine, but .300BLK works best with magazines that have followers shaped to that cartridge. Also, it is possible to chamber a round of .300BLK in a firearm that shoots .223 Rem./5.56, but it will not shoot. In fact, it’ll probably blow up your gun as you try to squeeze a .30 bullet into a .22 diameter hole.

This would be a bad thing. As a result, if you’re like me and have both .300BLK AR-15’s and .223 Rem./5.56 AR-15, it’s best to use a unique style of magazine with you .223 Rem./5.56 guns, and a completely different style of magazine with your .300BLK guns to avoid mixing up your ammo and causing a disaster when you press the trigger.

Optic: Lucid Optics P8 4x Prism Scope

The P8 is a new scope from Lucid Optics, an upgrade from the previous P7 prism optic. It’s a fixed, 4X optic, which makes it usable at shorter ranges and out to 300 or 400 yards. For really close encounters, however, that 4X magnification might be too much, so an offset set of backup iron sights or a red dot sight might be a good idea if your target is within bad breath distance.

One of the nicer features of this scope is that the illumination is powered by a single AAA battery, which means that spare batteries are both cheap and readily available. The illumination itself is a bit different, as Lucid uses a blue LED to light up the reticle inside this scope. The reason for this, Lucid says, is that blue light gives better contrast against most common objects and works better with night vision gear than other LED colors.

The reticle itself has both a 16-MOA rough aiming circle and a 2-MOA dot in the center. There is also 4-MOA circle at the bottom of the aiming circle that is ideal for close quarters work and elevation hash marks in 4-MOA increments below the aiming circle.

The optic, like just about everything that Lucid makes, is very clear and offers a lot of great features for the price. Lucid has recently invested a lot of time and energy into upgrading the coatings on their optics, and the difference is, well, clear.

Accessory: SIG Sauer SRD762-QD Suppressor

This is my personally-owned .30-caliber suppressor, and I bought it specifically to work with a .300BLK large format pistol that I own. The suppressor is very effective and can be attached and detached from my gun in a matter of seconds, thanks to its quick-disconnect muzzle device.

However, that quick detach (QD) muzzle device, while really useful, also highlights one of the problems with a QD mount suppressor versus one that uses threads to attach to your gun. SIG Sauer no longer makes this particular model of suppressor, I can still purchase QD muzzle devices from SIG Sauer directly, but its future is up for grabs.

In the meantime, the SRD-762QD on the APF Guardian shows the real strength of the .300BLK cartridge. Supersonic rounds (147 grains and lighter) can reach out to 300 meters, with ballistics similar to the 7.62x39mm round. Subsonic rounds that weigh more than 200 grains, however, are shorter-ranged, but hit with the power of a .45 ACP round and are seriously quiet. Quite often, the only things I hear when shooting .300BLK subsonic with a suppressor are the "sproing” of the buffer tube spring next to my ear and the gentle “thwack” as the round impacts the paper target downrange.

.300BLK may not be everybody’s cup of tea, but it certainly has its uses, especially if you own a .30-caliber suppressor and an AR, or better yet, one of the purpose-built ARs like the one we talked about today.



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