Head to head

.280 Rem vs .280 Ackley Imp: Maker-Page Loads and SAAMI Specs Side by Side

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

This page puts .280 Rem and .280 Ackley Imp side by side using only our own ammo guides, .280 Rem ammo (11 loads) and .280 Ackley Imp ammo (4 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. 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 .280 Rem and .280 Ackley Imp guides. Pressures are as SAAMI lists them.

Measure	.280 Rem	.280 Ackley Imp
SAAMI name	280 REMINGTON [280 REM] (previously 7mm Express Remington [7MM EXP REM])	280 ACKLEY IMPROVED [280 ACK IMP] (a cartridge separate from the 280 Remington)
Drawing issued / revised	06/20/1986 / 05/05/2022	02/01/2008 / 05/05/2022
Maximum average pressure (transducer)	60,000 psi	65,000 psi
Crusher pressure	Not in our .280 Rem guide	Not established
Cartridge overall length	3.150 in min to 3.330 in max	3.136 in min to 3.330 in max
Case length	2.540 in (−.020)	2.525 in (−.012)
Bullet diameter (as SAAMI prints it)	.2845 in (−.0030)	.2845 in (−.0030)
Bore / groove diameter	Not yet verified	Not yet verified
Twist and grooves	1 in 10.00, 4 grooves (marked optional)	1 in 9.00, 4 grooves (marked optional)
SAAMI reference velocity	Not yet verified (the PDF text does not clearly pair each weight with its velocity)	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; not among its listed exceptions)	24 in standard rifle test barrel (SAAMI’s general statement; not among its listed exceptions)

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 (where the guide table prints it) 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	.280 Rem loads in our table	.280 Ackley Imp loads in our table
Federal	test barrel not listed: 3 loads, 140 to 150 gr, 2,890 to 2,990 fps	test barrel not listed: 3 loads, 140 to 168 gr, 2,800 to 3,075 fps
Remington	test barrel not listed: 4 loads, 140 to 165 gr, 2,820 to 3,020 fps	—
Hornady	24 in test barrel: 1 load, 150 gr, 2,925 fps	24 in test barrel: 1 load, 162 gr, 2,850 fps
Nosler	24 in test barrel: 3 loads, 140 gr, 2,925 to 3,000 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	.280 Rem	.280 Ackley Imp
Hornady Precision Hunter	150 gr ELD-X® Precision Hunter®, 2,925 fps, 2,849 ft-lb, 24 in test barrel, item 81587	162 gr ELD-X® Precision Hunter®, 2,850 fps, 2,921 ft-lb, 24 in test barrel, item 85586

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 (transducer) (our guide records no crusher figure) for .280 Rem and 65,000 psi (transducer) (SAAMI establishes no crusher pressure) for .280 Ackley Imp. Source: ANSI/SAAMI Z299.4.
If bullet weight is your question: The .280 Rem loads in the table run from 140 gr to 165 gr; the .280 Ackley Imp loads in the table run from 140 gr to 168 gr. The ranges come from each guide’s own bullet-weight section. Source: .280 Rem guide and .280 Ackley Imp guide.
If you want to see the printed velocities: the slowest and fastest muzzle velocities in our table: for .280 Rem: 2,820 fps, test barrel not listed (Remington Core-Lokt 28417) and 3,020 fps, test barrel not listed (Remington Core-Lokt Tipped 29020). For .280 Ackley Imp they are 2,800 fps, test barrel not listed (Federal Berger Hybrid Hunter P280AIBCH1) and 3,075 fps, test barrel not listed (Federal Trophy Copper P280AITC1). 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 2.540 in (−.020), cartridge overall length 3.150 in min to 3.330 in max for .280 Rem; and case length 2.525 in (−.012), cartridge overall length 3.136 in min to 3.330 in max for .280 Ackley Imp. Check the cartridge named in your rifle’s manual or marked on its barrel. Source: ANSI/SAAMI Z299.4.

Not yet verified

The .280 Rem guide has 11 loads and the .280 Ackley Imp guide has 4, so load counts and ranges are not a measure of how many loads exist; they only reflect what is in our tables. .280 Ackley Imp has the thinner table (4 loads); we state that plainly and draw no conclusion from it.
SAAMI bore and groove diameters for .280 Rem and .280 Ackley Imp are not recorded in our guides, so that row is marked rather than filled. SAAMI crusher pressure is not recorded in our .280 Rem guide and is not established for .280 Ackley Imp.
SAAMI lists the .280 Ackley Improved as a cartridge separate from the .280 Remington (previously designated 7mm Express Remington). Check the cartridge named on your barrel or in your rifle’s manual; do not assume the two are interchangeable.
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.
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 .280 Rem ammo and .280 Ackley Imp ammo, plus 7mm-08 ammo, 7mm Rem Mag ammo, 7mm PRC ammo, .270 Win ammo, .30-06 ammo, 7mm-08 vs .308, .30-06 vs .270, 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 .280 Rem and .280 Ackley Imp?

SAAMI lists 60,000 psi (transducer) (our guide records no crusher figure) for .280 Rem and 65,000 psi (transducer) (SAAMI establishes no crusher pressure) for .280 Ackley Imp, 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, .280 Rem or .280 Ackley Imp?

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 (.280 Rem ammo and .280 Ackley Imp ammo), which copy maker product pages, and from ANSI/SAAMI Z299.4.

.280 Rem vs .280 Ackley Imp: Maker-Page Loads and SAAMI Specs Side by Side

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

Frequently asked questions

Sources

Keep exploring

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

Keep exploring

The Gun Release Report