.223 Remington Ammo Guide: 55 Grain, Twist Rates and Chambers

This .223 Remington ammo guide covers the cartridge, how it relates to 5.56 NATO, which bullet weights suit which barrels, and what we stock. Our .223 line is PMC Bronze 55 grain FMJ-BT, kept deep enough to sell by the 20-round box or the 1,000-round case. Each pack has a live count and a 360-degree spin of the actual box on its product page.

What .223 Remington is

.223 Remington is the commercial cartridge introduced in the 1960s, closely related to the military 5.56x45mm NATO. The outside dimensions are nearly identical, but .223 is loaded to lower pressure and a .223 chamber has a shorter throat. In practice, .223 Remington ammunition is safe in rifles marked .223 Remington, 5.56 NATO and .223 Wylde. 5.56 ammunition should only go in a .223-marked rifle if the maker approves it. Read the full 5.56 vs .223 answer before mixing them.

Who shoots .223

• AR-15 owners who want a lead-core, brass-case range load, or who shoot at ranges that ban steel-core bullets such as M855
• Bolt-action and varmint rifle owners, since many factory bolt guns are chambered in .223 Remington, not 5.56
• Ranch and pest control users, along with new rifle shooters who want mild recoil
• Reloaders, because brass-case, boxer-primed .223 like PMC Bronze can be reloaded

55 grain and your twist rate

55 grain is the classic .223 weight, and it stabilizes in nearly every barrel ever made for the cartridge. That includes slow 1:12 and 1:14 twists on older and varmint rifles, which may not stabilize heavier 62 to 77 grain bullets. If you are not sure of your twist rate, 55 grain is the safe default. Faster 1:7 to 1:9 barrels shoot 55 grain fine too.

The .223 we stock

PMC Bronze .223 Remington 55 grain FMJ-BT (223A) is a full metal jacket boat-tail bullet over a brass, boxer-primed case. The boat-tail base helps the bullet hold velocity downrange, which is why this style is common for general range work. We carry it in 20-round boxes, 200-round, 500-round and 1,000-round packs, so you can try a box before buying the case. The lead core means no steel-core range problems. See the full .223 Remington category for current stock, and our 5.56 NATO guide for the 62 grain M855 and SS109 lines.

Accuracy expectations

FMJ-BT range ammunition is built for consistency and volume, not match-grade precision. From a typical AR-15 carbine, expect groups that are fine for steel plates, drills and zeroing at 50 and 100 yards. Bolt-action rifles often group tighter with the same ammunition. If your zero shifts when you change loads, re-zero on paper rather than chasing it with the scope.

Buying, shipping and pickup

Shipping is by weight, so a 1,000-round case, roughly 27 to 30 pounds packed, usually ships more efficiently per round than smaller packs. Orders ship UPS Ground from Phoenix. Check where we ship. You must be 21 or older to order. In the Phoenix area, call 480-623-4515 and pick up Monday to Friday, 9am to 5pm, with ID.

.223 ammo questions

Can I shoot .223 in a 5.56 rifle?

Yes. A 5.56 NATO chamber safely fires .223 Remington. Some rifles show slightly different accuracy or velocity with .223 because of the longer 5.56 throat, but function is normal. The reverse is the combination to be careful with: 5.56 in a .223-only chamber.

What does FMJ-BT mean?

Full metal jacket, boat tail. The bullet is fully covered in a copper-alloy jacket at the front, and its base tapers like the back of a boat. The taper reduces drag, so the bullet holds velocity and drifts less in wind than a flat-base bullet of the same weight.

Is .223 FMJ good for varmints or coyotes?

FMJ bullets are designed not to expand, so they are a practice load. For varmints and predators, most hunters use a soft point, polymer-tip or hollow point varmint bullet. Check Arizona Game and Fish rules for the species and season you are hunting.

Is .223 brass reloadable?

Brass-case, boxer-primed .223 such as PMC Bronze can be reloaded with standard dies and equipment. Inspect cases for splits and measure length before reloading, and follow a published load manual.

More answers in our ammo FAQ, or browse all rifle ammo.