Blackout, 8.6 Blackout, 300gr Sierra MatchKing Subsonic Ammunition, 80 Round Bucket

The 8.6 Blackout 300gr Sierra MatchKing subsonic bucket puts 80 match grade rounds on your bench for $109.96, about $1.37 a round. It is the load we recommend for zeroing a new 8.6 Blackout rifle, tuning a suppressor and shooting groups, because the 300gr MatchKing is the most consistent bullet in the caliber’s subsonic range. It is not a hunting round, and this page explains why as well as what it does well.

What the bucket gives you

Eighty rounds in a resealable bucket, loaded on the same line and to the same inspection standard as the 20 round retail box. Buying the 8.6 Blackout 300gr Sierra MatchKing load in bulk saves about 30 percent against four boxes, and the bucket itself is the container most shooters end up carrying to the range anyway.

Every round uses factory new brass, a match primer and a charge tuned so the bullet leaves a 12 inch barrel just above 1,000 feet per second. Overall length and neck tension are held to the tolerances a match bullet deserves. That consistency is the whole point of paying for a MatchKing rather than a plain open tip bullet.

The Sierra MatchKing bullet

Sierra’s MatchKing family has set more national records than any other match bullet line, and the 300 grain .338 caliber version is one of the heaviest. It is a boat tail hollow point with a long secant ogive, a thin, uniform jacket and a lead core drawn to tight weight tolerances. Nothing about the design is meant to expand. Everything about it is meant to fly the same way every time.

In 8.6 Blackout that matters because subsonic bullets spend a long time in the air. A round that takes a third of a second to reach 100 yards has more time for wind to act on it than a supersonic bullet. The 300 grain MatchKing’s high ballistic coefficient of about 0.750 means it resists that drift far better than a lighter subsonic.

Velocity, drift and drop

Barrel	Muzzle velocity	Energy	Drop at 150 yd (100 yd zero)	Drop at 200 yd
8 inch	About 960 fps	About 615 ft lbs	About 14 inches	About 40 inches
12 inch	About 1,010 fps	About 680 ft lbs	About 13 inches	About 36 inches
16 inch	About 1,030 fps	About 705 ft lbs	About 12 inches	About 34 inches

Also in Subsonic Ammo & Suppressors: Blackout Silverback, 8.6 Blackout, 285gr Fracturing Subsonic Ammunition, 80 Round Bucket, Blackout, 8.6 Blackout, 285gr Fracturing Subsonic Hunting Ammunition, 20 Round Box and Blackout, 8.6 Blackout, 300gr Sierra MatchKing Subsonic Ammunition, 20 Round Box. Load guide: best 8.6 Blackout subsonic ammo for hunting.

The figures are rounded from our 8.6 Blackout ballistics chart. Run your own barrel and zero through the ballistics calculator for a card you can tape to the stock. Because the bullet’s coefficient is so high, its wind drift at 200 yards in a 10 mile per hour crosswind is only about 8 inches, roughly half what a 220 grain 300 Blackout subsonic shows at the same range.

The 8.6 Blackout 300gr Sierra MatchKing load also holds velocity unusually well. It arrives at 200 yards still doing around 950 feet per second, which is why it remains stable and accurate past the distances where lighter subsonics start to wander. Our ballistics guide explains the physics in more depth.

Shipping, tax and age

Ships to your home address in all 50 states. No tax stamp, no NFA paperwork, no dealer transfer and no tax added at checkout. Orders over $300 ship free. Ammunition is not an NFA item, so there is no dealer transfer or waiting period. Under federal law at 18 U.S.C. 922 no federal licence is needed to buy or possess ammunition. You must be 21 or older to purchase rifle ammunition, and an adult must sign for the parcel. Ammunition travels by ground carrier as a limited quantity shipment under 49 CFR 173.63, so air shipping is never offered.

Details are on the shipping and delivery page and in the FAQ. Ammunition cannot be returned once shipped, see the returns policy for damaged deliveries. The bucket weighs about 7 pounds packed and ships in one carton.

Every load we sell is manufactured to the pressure and dimensional standards published by SAAMI. If a match grade subsonic at bucket pricing is what your 8.6 needs, this is the one to order.

Frequently asked questions

Is the 8.6 Blackout 300gr Sierra MatchKing load for hunting?

No. Sierra builds the MatchKing for accuracy, with a thin jacket and a hollow point that is not designed to expand reliably in game. Use it for zeroing, group testing, suppressor tuning and match shooting. For hunting, choose the 285gr fracturing or 342gr Pork Shredder loads.

How is the 8.6 Blackout 300gr Sierra MatchKing bucket packed?

Eighty loose rounds in a resealable plastic bucket with a lid. It is the most economical way to buy this load and the bucket doubles as a range box.

What velocity does it run?

About 1,010 feet per second from a 12 inch barrel and 1,030 from a 16 inch, which keeps it subsonic in almost all conditions. On a freezing morning with a 16 inch barrel it can approach the sound barrier, so listen for a crack and step down barrel length if you hear one.

What is the ballistic coefficient?

The 8.6 Blackout 300gr Sierra MatchKing carries a G1 ballistic coefficient of about 0.750, which is exceptional for a subsonic load and the reason it drifts so little in wind compared with lighter bullets.