Head to head

.308 Win vs .300 Win Mag: Maker-Page Loads and SAAMI Specs Side by Side

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

This page puts .308 Winchester and .300 Winchester Magnum side by side using only our own ammo guides, .308 Win ammo (86 loads) and .300 Win Mag ammo (35 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, the centerfire rifle standard (approved Feb. 10, 2025). Pressures are maximum average pressure by transducer unless marked. The same figures appear in our .308 Win and .300 Win Mag guides.

Measure	.308 Winchester	.300 Winchester Magnum
SAAMI name	308 WINCHESTER [308 WIN]	300 WINCHESTER MAGNUM [300 WIN MAG]
Drawing issued / revised	05/29/1979 / 06/03/2022	04/21/1980 / 05/31/2022
Maximum average pressure (transducer)	62,000 psi	64,000 psi
Maximum average pressure (crusher)	52,000 CUP	54,000 CUP
Cartridge overall length	2.490 in min to 2.810 in max	3.215 in min to 3.340 in max
Case length	2.015 in (−.020)	2.620 in (−.020)
Bullet diameter	.309 in (−.003)	.309 in (−.003)
Bore / groove diameter	.300 in / .308 in	.300 in / .308 in
Twist and grooves on drawing	1 in 12.00 in; 4 grooves	1 in 10.00 in (marked optional); 6 grooves
SAAMI velocity test barrel	24.000 in	24 in (SAAMI's general rifle test-barrel statement; the .300 Win Mag is not among its listed exceptions)

SAAMI's velocity columns for these cartridges are not copied here, because the PDF text layout does not let us tie each velocity to one bullet weight with confidence.

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.

Maker	.308 Winchester loads in our table	.300 Winchester Magnum loads in our table
Federal	test barrel not listed: 26 loads, 130 to 205 gr, 1,000 to 3,050 fps	test barrel not listed: 18 loads, 150 to 200 gr, 2,810 to 3,150 fps
Remington	test barrel not listed: 16 loads, 150 to 205 gr, 1,050 to 2,840 fps	test barrel not listed: 7 loads, 150 to 190 gr, 2,850 to 3,290 fps
Hornady	13 in test barrel: 1 load, 178 gr, 2,260 fps 24 in test barrel: 21 loads, 125 to 180 gr, 2,600 to 3,000 fps	24 in test barrel: 9 loads, 150 to 200 gr, 2,860 to 3,275 fps 26 in test barrel: 1 load, 178 gr, 2,960 fps
Nosler	24 in test barrel: 12 loads, 110 to 175 gr, 2,600 to 3,150 fps test barrel not listed: 3 loads, 168 to 175 gr, 2,600 to 2,750 fps	—
Berger	26 in test barrel: 7 loads, 155.5 to 200.2 gr, 2,532 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 here side by side exactly as the maker pages print them. We match lines by the maker's own product-line name on each page. Compare only within a row, and check the test barrel in each cell.

Maker line	.308 Winchester	.300 Winchester Magnum
Federal Barnes TSX	150 gr Barnes Triple-Shock X Bullet (TSX), 2,820 fps, 2,648 ft-lb, test barrel not listed, item P308V 165 gr Barnes Triple-Shock X Bullet (TSX), 2,650 fps, 2,573 ft-lb, test barrel not listed, item P308H	180 gr Barnes Triple-Shock X Bullet (TSX), 2,960 fps, 3,502 ft-lb, test barrel not listed, item P300WP 165 gr Barnes Triple-Shock X Bullet (TSX), 3,050 fps, 3,408 ft-lb, test barrel not listed, item P300WR
Federal Trophy Copper	150 gr Trophy Copper, 2,820 fps, 2,648 ft-lb, test barrel not listed, item P308TC3 165 gr Trophy Copper, 2,700 fps, 2,671 ft-lb, test barrel not listed, item P308TC2	180 gr Trophy Copper, 2,960 fps, 3,502 ft-lb, test barrel not listed, item P300WTC1 165 gr Trophy Copper, 3,050 fps, 3,408 ft-lb, test barrel not listed, item P300WTC2
Federal Trophy Bonded Tip	165 gr Trophy Bonded Tip, 2,700 fps, 2,671 ft-lb, test barrel not listed, item P308TT2 180 gr Trophy Bonded Tip, 2,620 fps, 2,743 ft-lb, test barrel not listed, item P308TT1	180 gr Trophy Bonded Tip, 2,960 fps, 3,502 ft-lb, test barrel not listed, item P300WTT1 165 gr Trophy Bonded Tip, 3,050 fps, 3,408 ft-lb, test barrel not listed, item P300WTT2
Federal Berger Hybrid Hunter	168 gr Berger, 2,700 fps, 2,719 ft-lb, test barrel not listed, item P308BCH1	185 gr Berger Hybrid, 2,950 fps, 3,575 ft-lb, test barrel not listed, item P300WBCH1
Federal Terminal Ascent	175 gr Terminal Ascent, 2,600 fps, 2,627 ft-lb, test barrel not listed, item P308TA1	200 gr Terminal Ascent, 2,810 fps, 3,506 ft-lb, test barrel not listed, item P300WTA1 175 gr Terminal Ascent, 3,030 fps, 3,567 ft-lb, test barrel not listed, item P300WTA2
Federal ELD-X	178 gr ELD-X, 2,610 fps, 2,692 ft-lb, test barrel not listed, item P308ELDX1	200 gr ELD-X, 2,860 fps, 3,632 ft-lb, test barrel not listed, item P300WELDX1
Remington Core-Lokt	150 gr Pointed Soft Point Core Lokt, 2,820 fps, 2,648 ft-lb, test barrel not listed, item 27842 180 gr Pointed Soft Point Core Lokt, 2,620 fps, 2,743 ft-lb, test barrel not listed, item 21479 180 gr Core-Lokt Soft Point, 2,620 fps, 2,743 ft-lb, test barrel not listed, item 27844	180 gr Pointed Soft Point Core Lokt, 2,960 fps, 3,502 ft-lb, test barrel not listed, item 29497 150 gr Pointed Soft Point Core Lokt, 3,290 fps, 3,605 ft-lb, test barrel not listed, item 29495
Remington Core-Lokt Copper	150 gr Copper HP, 2,820 fps, 2,648 ft-lb, test barrel not listed, item R27854	180 gr Copper HP, 2,850 fps, 3,246 ft-lb, test barrel not listed, item R27858
Remington Core-Lokt Tipped	150 gr Core-Lokt Tipped, 2,840 fps, 2,686 ft-lb, test barrel not listed, item 29039 165 gr Core-Lokt Tipped, 2,700 fps, 2,671 ft-lb, test barrel not listed, item 29044 180 gr Core-Lokt Tipped, 2,640 fps, 2,785 ft-lb, test barrel not listed, item 29041	180 gr Core-Lokt Tipped, 2,980 fps, 3,549 ft-lb, test barrel not listed, item R29038
Remington Premier CuT	150 gr Copper Tipped, 2,800 fps, 2,611 ft-lb, test barrel not listed, item R22344	180 gr Copper Tipped, 2,960 fps, 3,502 ft-lb, test barrel not listed, item R22345
Remington Premier Scirocco	165 gr Swift Scirocco Bonded, 2,680 fps, 2,631 ft-lb, test barrel not listed, item 29332	180 gr Swift Scirocco Bonded, 2,960 fps, 3,502 ft-lb, test barrel not listed, item R29330
Remington Premier Long Range	172 gr Speer Impact, 2,635 fps, 2,651 ft-lb, test barrel not listed, item R21345	190 gr Speer Impact, 2,885 fps, 3,511 ft-lb, test barrel not listed, item R21346
Hornady American Whitetail	150 gr InterLock SP, 2,820 fps, 2,649 ft-lb, 24 in test barrel, item 8090 165 gr InterLock SP, 2,700 fps, 2,671 ft-lb, 24 in test barrel, item 80904	180 gr InterLock® SP American Whitetail®, 2,960 fps, 3,502 ft-lb, 24 in test barrel, item 82044 150 gr InterLock® SP American Whitetail®, 3,275 fps, 3,572 ft-lb, 24 in test barrel, item 8204
Hornady Outfitter	150 gr CX, 2,800 fps, 2,611 ft-lb, 24 in test barrel, item 80982 165 gr CX, 2,610 fps, 2,496 ft-lb, 24 in test barrel, item 809864	180 gr. CX® Outfitter®, 2,960 fps, 3,502 ft-lb, 24 in test barrel, item 821974
Hornady Superformance	150 gr SST, 3,000 fps, 2,997 ft-lb, 24 in test barrel, item 80933 150 gr CX, 2,900 fps, 2,801 ft-lb, 24 in test barrel, item 80944 165 gr SST, 2,840 fps, 2,955 ft-lb, 24 in test barrel, item 80983 165 gr CX, 2,750 fps, 2,771 ft-lb, 24 in test barrel, item 80990 180 gr SST, 2,650 fps, 2,807 ft-lb, 24 in test barrel, item 80772	180 gr SST® Superformance®, 3,130 fps, 3,915 ft-lb, 24 in test barrel, item 82193 165 gr. CX® Superformance®, 3,260 fps, 3,893 ft-lb, 24 in test barrel, item 820264
Hornady Precision Hunter	178 gr ELD-X, 2,600 fps, 2,671 ft-lb, 24 in test barrel, item 80994	200 gr ELD-X® Precision Hunter®, 2,860 fps, 3,632 ft-lb, 24 in test barrel, item 82002 178 gr ELD-X® Precision Hunter®, 2,960 fps, 3,463 ft-lb, 26 in test barrel, item 82041
Federal Gold Medal Sierra MatchKing	168 gr Sierra Matchking Boat-Tail Hollow Point, 2,650 fps, 2,619 ft-lb, test barrel not listed, item GM308M 175 gr Sierra Matchking Boat-Tail Hollow Point, 2,600 fps, 2,627 ft-lb, test barrel not listed, item GM308M2	190 gr Sierra Matchking Boat-Tail Hollow Point, 2,900 fps, 3,548 ft-lb, test barrel not listed, item GM300WM

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 62,000 psi for .308 Winchester and 64,000 psi for .300 Winchester Magnum by transducer, and 52,000 CUP and 54,000 CUP by crusher. Source: ANSI/SAAMI Z299.4.
If bullet weight is your question: the .308 Winchester loads in our table run from 110 gr (Nosler Varmageddon 40272) to 205 gr (Federal Subsonic 308SUB1). The .300 Winchester Magnum loads run from 150 gr (Federal Power-Shok Rifle 300WGS) to 200 gr (Federal ELD-X P300WELDX1). Sources: those maker pages.
If you want to see the printed velocities: the slowest and fastest .308 Winchester muzzle velocities in our table are 1,000 fps, test barrel not listed (Federal Subsonic F308TF3SUB) and 3,150 fps, 24 in test barrel (Nosler Varmageddon 40272). For .300 Winchester Magnum they are 2,810 fps, test barrel not listed (Federal Terminal Ascent P300WTA1) and 3,290 fps, test barrel not listed (Remington Core-Lokt 29495). 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's rifle test barrel is 24 in for both cartridges, and 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 2.015 in (−.020) for .308 Winchester and 2.620 in (−.020) for .300 Winchester Magnum, cartridge overall length 2.490 in min to 2.810 in max and 3.215 in min to 3.340 in max, and the same bullet diameter, .309 in (−.003). 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).
Speer's and CCI's caliber menus we captured on Nov. 4 list only handgun and rimfire calibers, so neither maker is in either guide.
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 .308 Win ammo and .300 Win Mag ammo, the .308 Win barrel length data, the .300 Win Mag barrel length data, .300 Win Mag vs .300 PRC, the new ammo of 2026, all ammo releases and .270 Win vs .308 Win, 6.5 PRC vs .300 PRC, .338 Lapua vs .300 Win Mag, .270 WSM vs .300 WSM, all comparisons.

Frequently asked questions

What is the SAAMI maximum pressure for .308 Win and .300 Win Mag?

SAAMI lists 62,000 psi (52,000 CUP) for .308 Winchester and 64,000 psi (54,000 CUP) for .300 Winchester Magnum, in ANSI/SAAMI Z299.4.

Do .308 Win and .300 Win Mag use the same bullet diameter?

SAAMI lists .309 in (−.003) for both in ANSI/SAAMI Z299.4.

Which test barrel do the makers list?

It varies by maker and load. SAAMI's rifle test barrel is 24 in for both cartridges. Our tables show the barrel each maker page lists next to every velocity, and many pages list none.

Which is better, .308 Winchester or .300 Winchester Magnum?

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 (.308 Win ammo and .300 Win Mag 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