Head to head

.270 WSM vs .300 WSM: Maker-Page Loads and SAAMI Specs Side by Side

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

This page puts .270 WSM and .300 WSM side by side using only our own ammo guides, .270 WSM ammo (8 loads) and .300 WSM ammo (17 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 firearm’s maker says it is chambered for.

SAAMI specs side by side

These are the figures in ANSI/SAAMI Z299.4, as already recorded in the SAAMI sections of our .270 WSM and .300 WSM guides. Pressures are as SAAMI lists them.

Measure	.270 WSM	.300 WSM
SAAMI name	270 WINCHESTER SHORT MAGNUM [270 WSM]	300 WINCHESTER SHORT MAGNUM [300 WSM]
Drawing issued / revised	02/01/2002 / 11/15/2021	06/13/2001 / 06/01/2022
Maximum average pressure (transducer)	65,000 psi	65,000 psi
Crusher pressure	None listed (our guide: crusher pressures are not established)	None listed (our guide: crusher pressures are not established)
Cartridge overall length	2.560 in min to 2.860 in max	2.560 in min to 2.860 in max
Case length	2.100 in (−.020)	2.100 in (−.020)
Bullet diameter (as SAAMI prints it)	.278 in (−.003)	.309 in (−.003)
Bore / groove diameter	.270 in / .277 in	.300 in / .308 in
Twist and grooves	1 in 10.00 in, right-hand (marked optional), 4 grooves	1 in 10.00 in, right-hand (marked optional), 4 grooves
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)

SAAMI measures pressure by transducer (psi) and, for some cartridges, by crusher (CUP). Compare psi with psi and CUP with CUP, never across. A “None listed” row means our guide records no figure; it is not a statement about the cartridge.

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	.270 WSM loads in our table	.300 WSM loads in our table
Federal	test barrel not listed: 5 loads, 130 to 150 gr, 3,060 to 3,280 fps	test barrel not listed: 11 loads, 165 to 200 gr, 2,810 to 3,130 fps
Remington	test barrel not listed: 1 load, 130 gr, 3,285 fps	test barrel not listed: 3 loads, 150 to 180 gr, 2,980 to 3,340 fps
Hornady	24 in test barrel: 2 loads, 130 to 145 gr, 3,100 to 3,150 fps	24 in test barrel: 3 loads, 165 to 200 gr, 2,820 to 3,130 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	.270 WSM	.300 WSM
Federal Berger Hybrid Hunter	140 gr Berger Hybrid, 3,200 fps, 3,183 ft-lb, test barrel not listed, item P270WSMBCH1	185 gr Berger Hybrid, 2,950 fps, 3,575 ft-lb, test barrel not listed, item P300WSMBCH1
Federal Fusion Rifle	150 gr Fusion Soft Point, 3,060 fps, 3,118 ft-lb, test barrel not listed, item F270WSMFS1	165 gr Fusion Soft Point, 3,100 fps, 3,521 ft-lb, test barrel not listed, item F300WSMFS1 180 gr Fusion Soft Point, 2,950 fps, 3,478 ft-lb, test barrel not listed, item F300WSMFS2
Federal Power-Shok Rifle	130 gr Jacketed Soft Point, 3,250 fps, 3,049 ft-lb, test barrel not listed, item 270WSME	180 gr Jacketed Soft Point, 2,980 fps, 3,549 ft-lb, test barrel not listed, item 300WSMC
Federal Terminal Ascent	136 gr Terminal Ascent, 3,240 fps, 3,170 ft-lb, test barrel not listed, item P270WSMTA1	200 gr Terminal Ascent, 2,810 fps, 3,506 ft-lb, test barrel not listed, item P300WSMTA1
Federal Trophy Copper	130 gr Trophy Copper, 3,280 fps, 3,105 ft-lb, test barrel not listed, item P270WSMTC1	180 gr Trophy Copper, 2,960 fps, 3,502 ft-lb, test barrel not listed, item P300WSMTC1
Hornady Outfitter	130 gr CX® Outfitter®, 3,150 fps, 2,864 ft-lb, 24 in test barrel, item 805574	180 gr CX® Outfitter®, 2,900 fps, 3,361 ft-lb, 24 in test barrel, item 822034
Hornady Precision Hunter	145 gr ELD-X® Precision Hunter®, 3,100 fps, 3,094 ft-lb, 24 in test barrel, item 80558	200 gr ELD-X® Precision Hunter®, 2,820 fps, 3,531 ft-lb, 24 in test barrel, item 82208
Remington Core-Lokt	130 gr Pointed Soft Point Core Lokt, 3,285 fps, 3,115 ft-lb, test barrel not listed, item 28940	150 gr Pointed Soft Point Core Lokt, 3,320 fps, 3,671 ft-lb, test barrel not listed, item 29489

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 65,000 psi by transducer for .270 WSM and 65,000 psi by transducer for .300 WSM. Source: ANSI/SAAMI Z299.4.
If bullet weight is your question: the .270 WSM loads in our table run from 130 gr (Federal Power-Shok Rifle 270WSME) to 150 gr (Federal Fusion Rifle F270WSMFS1). The .300 WSM loads run from 150 gr (Remington Core-Lokt 29489) to 200 gr (Federal ELD-X P300WSMELDX1). Sources: those maker pages.
If you want to see the printed velocities: the slowest and fastest .270 WSM muzzle velocities in our table are 3,060 fps, test barrel not listed (Federal Fusion Rifle F270WSMFS1) and 3,285 fps, test barrel not listed (Remington Core-Lokt 28940). For .300 WSM they are 2,810 fps, test barrel not listed (Federal Terminal Ascent P300WSMTA1) and 3,340 fps, test barrel not listed (Remington Core-Lokt Tipped 29043). 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: of the .270 WSM loads, 6 with no test barrel listed, 2 list 24 in; of the .300 WSM loads, 14 with no test barrel listed, 3 list 24 in. 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 in our guides.
If chamber fit is your question: SAAMI publishes a separate cartridge drawing for each, with case length 2.100 in (−.020) for .270 WSM and 2.100 in (−.020) for .300 WSM, and cartridge overall length 2.560 in min to 2.860 in max and 2.560 in min to 2.860 in max. Check the cartridge named in your firearm’s manual or marked on its barrel. Source: ANSI/SAAMI Z299.4.

Not yet verified

Makers and loads missing from either guide’s table (for example Winchester or SIG Sauer, where a guide says so) are listed in the “Not yet verified” section of that guide.
SAAMI reference velocities are not copied in our guides, because the PDF text does not clearly pair each weight with its velocity.
A dash in the range table means the maker has no load in that guide’s table, not that the maker sells none.
Maker status (in stock, discontinued) is not shown here. See each guide for the status wording on the maker pages.
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 .270 WSM ammo and .300 WSM ammo, the barrel length vs velocity data, .270 Win vs .308 Win, .300 Win Mag vs .300 PRC, .308 Win vs .300 Win Mag, the new ammo of 2026, all ammo releases and all comparisons.

Frequently asked questions

What is the SAAMI maximum pressure for .270 WSM and .300 WSM?

SAAMI lists 65,000 psi (transducer) for .270 WSM, and 65,000 psi (transducer) for .300 WSM, in ANSI/SAAMI Z299.4.

Which test barrel do the makers list?

It varies by maker and load. Our tables show the barrel each maker page lists next to every velocity, and many pages list none. See the ranges table above.

Which is better, .270 WSM or .300 WSM?

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 (.270 WSM ammo and .300 WSM 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

Keep exploring

The Gun Release Report