Blackout Ammunition .300 Blackout 125gr Sierra MatchKing, 20 Round Box

The Blackout Ammunition .300 Blackout 125gr Sierra MatchKing, 20 Round Box is a 300 Blackout load held in stock. What follows is the practical version: construction, velocity, and who it suits.

Specifications

Cartridge	300 Blackout
Bullet weight	125 grain
Projectile	Match Hollow Point Boat Tail
Bullet diameter	.308
Typical muzzle velocity	1,000 fps subsonic, 2,100 to 2,300 fps supersonic
Usual twist rate	1:7 to 1:8
Platform	AR-15
Rounds per pack	20
SKU	GA300125SMK
Price	$32.99
Cost per round	$1.650

What this match hollow point boat tail bullet is built to do

This is a a target design chosen for consistency rather than terminal effect. The hollow point is a manufacturing artefact of the jacket drawing process, not an expansion mechanism, so it should not be selected as a hunting bullet.

Bullet weight and bullet construction get conflated constantly. Weight sets trajectory and momentum; construction sets what happens on impact.

What 300 BLACKOUT is good at

Full powder burn by roughly 9 inches, which is why it dominates short barrel builds.

Muzzle velocity for 300 Blackout typically runs 1,000 fps subsonic, 2,100 to 2,300 fps supersonic, from a AR-15 platform with a 1:7 to 1:8 twist. Expect real world variation against those figures. A chronograph and ten rounds will tell you more than any spec sheet.

Choosing this bullet weight

At 125 grain this is on the lighter side for 300 Blackout. Lighter bullets leave the muzzle faster and shoot flatter, which helps on smaller targets and at distance, but they bleed velocity sooner and depend more on impact speed to do their job.

Pack size and cost per round

20 rounds at $32.99 works out at $1.650 per round. A box this size suits load development, hunting stock and defensive carry rather than high volume practice.

Compliance

Shipping rules for ammunition vary by state and sometimes by city. Some destinations require a licence, an approved recipient, or refuse delivery entirely. Check before you order rather than after. See our shipping and delivery page for the current detail.

Intended use

Before buying, be honest about the use case. This is a target and load development projectile. It is not a hunting bullet, and choosing it for game is the single most common mistake with this bullet line.

Barrel length and velocity

Do not assume box velocity applies to your barrel. Published figures usually come from long test barrels, and real rifles run slower. For 300 Blackout specifically, expect 1,000 fps subsonic, 2,100 to 2,300 fps supersonic as the published band and treat your own chronograph as the authority.

How to store this

Ammunition stores for decades if you keep moisture and temperature swings away from it. Sealed containers with a desiccant pack beat an open box in a shed every time.

See also

Browse our 300 Blackout ammunition for other weights and projectile types, or run your setup through the ballistics calculator.

Choosing 300 Blackout over something else

Against 5.56 it gives up range and gains suppressed performance and short barrel efficiency. Against 8.6 Blackout it gives up roughly half the subsonic energy and gains an AR-15 platform and far cheaper ammunition.

None of that makes one cartridge better in the abstract. It makes them better at different jobs, and the job is yours to define.

How this is stored

What ships is sealed factory ammunition, stored indoors and rotated so the oldest stock moves first. Packing is chosen to stop cartridges moving inside the box.

New to this cartridge? Start with a single box. Barrel to barrel variation is real, and the only way to know how a load performs in your rifle is to shoot it.

Frequently asked questions

What rifle does 300 Blackout run in?

300 Blackout is normally chambered in a AR-15 platform with a 1:7 to 1:8 twist. Full powder burn by roughly 9 inches, which is why it dominates short barrel builds.

What velocity should I expect from 300 Blackout?

Typically 1,000 fps subsonic, 2,100 to 2,300 fps supersonic. Barrel length, temperature and lot all shift it, so chronograph your own rifle.

Is the match hollow point boat tail projectile suitable for what I am shooting?

It is a a target design chosen for consistency rather than terminal effect. The hollow point is a manufacturing artefact of the jacket drawing process, not an expansion mechanism, so it should not be selected as a hunting bullet. Match that against your intended use before buying.

Why choose 125 grain?

Weight sets the trade between velocity and momentum. 125 grain is one point on that curve; the right pick depends on your barrel, your distance and your target rather than on the number itself.

What is in the pack?

20 rounds at $32.99, which is $1.650 per round.

Do you actually have this in stock?

Yes, this is held stock rather than drop shipped, and the listing comes down when it sells out.

Can you ship this to my state?

In most cases yes, though several states and cities restrict ammunition shipments or require a licence. Our shipping page lists current restrictions.

Do you sell components for this cartridge?

We stock projectiles and brass for several of our calibres alongside loaded ammunition. Check the projectiles and brass category for what is currently available.

Do you offer bulk pricing?

Larger pack sizes carry a lower cost per round, which is listed on each product page so you can compare directly rather than doing the arithmetic yourself.

How is this stored before it ships?

Indoors at stable temperature, rotated oldest first, and packed so cartridges do not move in transit.