Head to head

.243 Win vs 6mm Creedmoor: Maker-Page Loads and SAAMI Specs Side by Side

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

This page puts .243 Win and 6mm Creedmoor side by side using only our own ammo guides, .243 Win ammo (26 loads) and 6mm Creedmoor ammo (11 loads), 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, 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 .243 Win and 6mm Creedmoor guides. Pressures are as SAAMI lists them.

Measure	.243 Win	6mm Creedmoor
SAAMI name	243 WINCHESTER [243 WIN]	6MM CREEDMOOR [6MM CM]
Drawing issued / revised	05/29/1979 / 04/05/2022	06/14/2017 / 11/17/2021
Maximum average pressure (transducer)	60,000 psi	62,000 psi
Crusher pressure	52,000 CUP	Not established
Cartridge overall length	2.540 in min to 2.710 in max	2.550 in min to 2.800 in max
Case length	2.045 in (−.020)	1.920 in (−.020)
Bullet diameter (as SAAMI prints it)	.243 in (−.003)	.2434 in (−.003)
Bore / groove diameter	.237 in / .243 in	.237 in / .243 in
Twist and grooves	1 in 10.00 in, right-hand (marked optional), 6 grooves	1 in 7.50 in, right-hand (marked optional), 6 grooves
SAAMI reference velocity	Not in our .243 guide	Not yet verified (the PDF text does not clearly pair each weight with its velocity)
SAAMI velocity test barrel	24 in standard rifle test barrel (SAAMI’s general statement; .243 is not among its listed exceptions)	24 in standard rifle test barrel (SAAMI’s general statement; 6mm Creedmoor is not among its listed exceptions)

SAAMI prints the bullet diameter as .243 in for the .243 Win and .2434 in for the 6mm Creedmoor, and lists the same .237 in bore and .243 in groove for both. We copy the figures as printed and draw no conclusion about interchangeability: the case lengths and cartridge drawings differ.

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	.243 Win loads in our table	6mm Creedmoor loads in our table
Federal	test barrel not listed: 11 loads, 75 to 100 gr, 2,960 to 3,425 fps	test barrel not listed: 3 loads, bullet weight not printed in our table, 2,900 to 3,000 fps
Remington	test barrel not listed: 6 loads, 75 to 100 gr, 2,960 to 3,375 fps	test barrel not listed: 2 loads, bullet weight not printed in our table, 3,000 fps
Hornady	24 in test barrel: 9 loads, 58 to 100 gr, 2,800 to 3,925 fps	24 in test barrel: 6 loads, 80 to 108 gr, 2,960 to 3,325 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	.243 Win	6mm Creedmoor
Remington Core-Lokt	100 gr Pointed Soft Point Core Lokt, 2,960 fps, 1,945 ft-lb, test barrel not listed, item R27802	Pointed Soft Point Core Lokt, 3,000 fps, 1,998 ft-lb, test barrel not listed, item 29049
Hornady Precision Hunter	90 gr ELD-X® Precision Hunter®, 3,150 fps, 1,983 ft-lb, 24 in test barrel, item 80462	103 gr ELD-X® Precision Hunter®, 3,050 fps, 2,127 ft-lb, 24 in test barrel, item 81392
Hornady Superformance	95 gr SST® Superformance®, 3,185 fps, 2,140 ft-lb, 24 in test barrel, item 80463 58 gr V-MAX® Superformance®, 3,925 fps, 1,984 ft-lb, 24 in test barrel, item 8343	90 gr CX® Superformance®, 3,325 fps, 2,209 ft-lb, 24 in test barrel, item 813944

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 60,000 psi by transducer for .243 Win (plus 52,000 CUP by crusher) and 62,000 psi by transducer for 6mm Creedmoor, with no crusher pressure established. Source: ANSI/SAAMI Z299.4.
If bullet weight is your question: the .243 Win loads in our table run from 58 gr (Hornady Superformance 8343) to 100 gr (Federal Power-Shok Rifle 243B). The 6mm Creedmoor loads run from 80 gr (Hornady V-Match 81397) to 108 gr (Hornady Match 81391). Sources: those maker pages.
If you want to see the printed velocities: the slowest and fastest .243 Win muzzle velocities in our table are 2,800 fps, 24 in test barrel (Hornady Custom Lite 80466) and 3,925 fps, 24 in test barrel (Hornady Superformance 8343). For 6mm Creedmoor they are 2,900 fps, test barrel not listed (Federal Gold Medal Berger GM6CRDLRHT1) and 3,325 fps, 24 in test barrel (Hornady Superformance 813944). These come from different barrels and bullets, so we show them side by side without a difference. Sources: those maker pages.
If you are comparing against a box or a chronograph: SAAMI says all standard rifle test barrels are 24 in long, and neither cartridge is on its list of exceptions. 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, with case length 2.045 in (−.020) for .243 Win and 1.920 in (−.020) for 6mm Creedmoor, and cartridge overall length 2.540 in min to 2.710 in max and 2.550 in min to 2.800 in max. Check the cartridge named in your rifle’s manual or marked on its barrel. Source: ANSI/SAAMI Z299.4.

Not yet verified

Winchester and SIG Sauer loads are not in either guide’s table (see the “Not yet verified” section of each guide).
A dash in the range table means the maker has no load in that guide’s table, not that the maker sells none.
Many 6mm Creedmoor rows in our guide print no bullet weight on the maker page, so weight ranges for them are partial (see the notes in the range table).
SAAMI reference velocities are not recorded for either cartridge in our guides.
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 .243 Win ammo and 6mm Creedmoor ammo, the barrel length vs velocity data, 6.5 Creedmoor vs 6.5 PRC, .308 Win vs .30-06, .270 Win vs .308 Win, the new ammo of 2026, all ammo releases and .243 Win vs .270 Win, all comparisons.

Frequently asked questions

What is the SAAMI maximum pressure for .243 Win and 6mm Creedmoor?

SAAMI lists 60,000 psi (transducer) and 52,000 CUP (crusher) for .243 Win, and 62,000 psi (transducer) with no crusher pressure for 6mm Creedmoor, in ANSI/SAAMI Z299.4.

Do .243 Win and 6mm Creedmoor have the same bullet diameter?

SAAMI prints .243 in (−.003) for .243 Win and .2434 in (−.003) for 6mm Creedmoor, and lists a .237 in bore and .243 in groove for both. They are separate cartridges with different case lengths (2.045 in and 1.920 in); use the one your rifle is marked for.

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, .243 Win or 6mm Creedmoor?

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 (.243 Win ammo and 6mm Creedmoor 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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