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.204 Ruger vs .223 Rem: Maker-Page Loads and SAAMI Specs Side by Side

By Cole Harlan, EditorUpdated Nov 5, 2026How we verifyEditorial standards

This page puts .204 Ruger and .223 Rem side by side using only our own ammo guides, .204 Ruger ammo (9 loads) and .223 Rem ammo (40 loads) (the guide lists 44 loads for .223 Rem and 5.56 NATO together; 40 are labeled “223 Rem” and only those are used here), plus the cartridge specs SAAMI publishes in ANSI/SAAMI Z299.4, its centerfire rifle standard. The guides copy bullet weights, velocities, energies and test barrels from maker product pages (checked Nov. 4 and 5, 2026). We don’t rate or rank cartridges, and we don’t subtract one maker’s velocity from another’s, because their test barrels differ.

How to read this page: every number is copied from a maker page or from SAAMI, and a test barrel length sits next to every velocity (or says the maker lists none). A dash (—) means the maker has no load in our tables for that cartridge. Fire only the cartridge your rifle’s maker says it is chambered for.

SAAMI specs side by side

These are the figures in ANSI/SAAMI Z299.4 (approved Feb. 10, 2025), as already recorded in the SAAMI sections of our .204 Ruger and .223 Rem guides. Pressures are as SAAMI lists them.

Measure	.204 Ruger	.223 Rem
SAAMI name	204 RUGER [204 RUGER]	223 REMINGTON [223 REM]
Drawing issued / revised	06/23/2004 / 04/24/2023	04/21/1980 / 09/25/2023
Maximum average pressure (transducer)	57,500 psi	55,000 psi
Crusher pressure	Not established	Not in our .223 guide
Cartridge overall length	2.125 in min to 2.260 in max	2.125 in min to 2.260 in max
Case length	1.850 in (−.020)	1.760 in (−.030)
Bullet diameter (as SAAMI prints it)	.2045 in (−.0030)	.2245 in (−.0030)
Bore / groove diameter	Not yet verified	.219 in / .224 in
Twist and grooves	1 in 12.00, 6 grooves (marked optional)	Not in our .223 guide
SAAMI reference velocity	Not yet verified (the PDF text does not clearly pair each weight with its velocity)	Not in our .223 guide
SAAMI velocity test barrel	24 in standard rifle test barrel (SAAMI’s general statement; not among its listed exceptions)	Not in our .223 guide

The .223 Rem column shows only SAAMI’s 223 Remington drawing (55,000 psi). Our guide records no 5.56 NATO pressure, and we do not put one in that cell. Fields our .223 guide does not record are marked, not filled from elsewhere.

Load ranges by maker and test barrel

Each line groups one maker’s loads that share a test barrel, so a velocity is only ever shown with the barrel it was measured in. Ranges are bullet weight and muzzle velocity as the maker page prints them. Do not read across makers: their barrels and bullets differ. For how barrel length moves velocity, see our barrel length vs velocity data.

Maker	.204 Ruger loads in our table	.223 Rem loads in our table
Federal	test barrel not listed: 1 load, 32 gr, 4,100 fps	test barrel not listed: 20 loads, 50 to 77 gr, 2,720 to 3,400 fps
Remington	test barrel not listed: 2 loads, 32 to 40 gr, 3,900 to 4,225 fps	—
Hornady	26 in test barrel: 3 loads, 24 to 40 gr, 3,900 to 4,400 fps	24 in test barrel: 20 loads, 35 to 75 gr, 2,790 to 4,000 fps
Nosler	24 in test barrel: 3 loads, 32 to 40 gr, 3,625 to 4,000 fps	—

Same maker, same line, both cartridges

Where one maker sells the same product line in both cartridges, the loads are listed side by side exactly as the maker pages print them. We match lines by the maker’s own product-line name in our guide tables. Compare only within a row, and check the test barrel in each cell.

Maker line	.204 Ruger	.223 Rem
Federal Varmint & Predator	32 gr Hornady® V-Max®, 4,100 fps, 1,194 ft-lb, test barrel not listed, item V204VM32	50 gr Jacketed Hollow Point, 3,325 fps, 1,227 ft-lb, test barrel not listed, item AE223G 50 gr Jacketed Hollow Point, 3,325 fps, 1,227 ft-lb, test barrel not listed, item AE22350VP 53 gr Hornady® V-Max®, 3,400 fps, 1,360 ft-lb, test barrel not listed, item V223VM53 53 gr Hornady® V-Max®, 3,400 fps, 1,360 ft-lb, test barrel not listed, item V223VM53B

What the sources say when you choose

These are points taken from the figures above, each with the page it rests on. They are not recommendations or scores.

If pressure rating is your question: SAAMI lists a maximum average pressure of 57,500 psi (transducer) (SAAMI establishes no crusher pressure) for .204 Ruger and 55,000 psi (transducer) (our guide records no crusher figure) for .223 Rem. Source: ANSI/SAAMI Z299.4.
If bullet weight is your question: The .204 Ruger loads in our table run from 24 gr (Hornady Superformance Varmint 83209) to 40 gr (Remington Premier AccuTip-V 29220). The .223 Rem loads in our table run from 35 gr (Hornady Superformance 83266) to 77 gr (Federal Gold Medal Sierra MatchKing GM223M3). Sources: those maker pages.
If you want to see the printed velocities: the slowest and fastest muzzle velocities in our table: for .204 Ruger: 3,625 fps, 24 in test barrel (Nosler Ballistic Tip Varmint 61021) and 4,400 fps, 26 in test barrel (Hornady Superformance Varmint 83209). For .223 Rem they are 2,720 fps, test barrel not listed (Federal Gold Medal Sierra MatchKing GM223M3) and 4,000 fps, 24 in test barrel (Hornady Superformance 83266). These come from different barrels and bullets, so we show them side by side without subtracting.
If you are comparing against a box or a chronograph: SAAMI says all standard rifle test barrels are 24 in long. Many maker pages list a different barrel or none, as the tables above show. A shorter barrel than the one a maker lists will likely give lower velocities than the box; see our barrel length vs velocity data. Source: ANSI/SAAMI Z299.4 and the maker pages linked above.
If chamber fit is your question: SAAMI publishes a separate cartridge drawing for each: case length 1.850 in (−.020), cartridge overall length 2.125 in min to 2.260 in max for .204 Ruger; and case length 1.760 in (−.030), cartridge overall length 2.125 in min to 2.260 in max for .223 Rem. Check the cartridge named in your rifle’s manual or marked on its barrel. Source: ANSI/SAAMI Z299.4.

Not yet verified

Our 5.56/.223 guide lists 44 loads; 40 are labeled “223 Rem” and 4 are labeled 5.56 (NATO or 5.56x45mm). Only the 40 “223 Rem” loads are used on this page.
SAAMI’s rifle standard has no separate 5.56x45mm NATO entry, per our guide. The .223 Rem column uses only the 223 Remington drawing, and no 5.56 NATO pressure is shown.
Winchester and other makers not shown in a column are not in that guide’s table (see the “Not yet verified” section of each guide), so a dash means no load in our table, not that the maker sells none.
Some SAAMI fields are not recorded for .204 Ruger and .223 Rem in our guides (marked above); we have not filled them from other sources.
Prices, recoil, accuracy and hands-on results are not in our data, so this page says nothing about them.

See the full tables in our .204 Ruger ammo and 5.56/.223 ammo, plus 5.56 vs .223 and SAAMI’s 5.56 Commercial, 300 Blackout vs 5.56, .22-250 ammo, 5.56/.223 barrel length vs velocity, the SAAMI maximum average pressure table, the barrel length vs velocity data, the new ammo of 2026, all ammo releases, all comparisons.

Frequently asked questions

What is the SAAMI maximum pressure for .204 Ruger and .223 Rem?

SAAMI lists 57,500 psi (transducer) (SAAMI establishes no crusher pressure) for .204 Ruger and 55,000 psi (transducer) (our guide records no crusher figure) for .223 Rem, in ANSI/SAAMI Z299.4.

Which test barrel do the makers list?

It varies by maker and load. SAAMI says standard rifle test barrels are 24 in. Our tables show the barrel each maker page lists next to every velocity, and many pages list none.

Which is better, .204 Ruger or .223 Rem?

We don't rate or rank cartridges. This page copies maker-page figures and SAAMI specs side by side, and it does not cover price, recoil or hands-on results.

Where do these numbers come from?

From our own ammo guides (.204 Ruger ammo and .223 Rem ammo), which copy maker product pages, and from ANSI/SAAMI Z299.4.

SAAMI specs side by side

Load ranges by maker and test barrel

Same maker, same line, both cartridges

What the sources say when you choose

Not yet verified

Related guides

Frequently asked questions

Sources

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