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.300 RUM vs .300 PRC: Maker-Page Loads and SAAMI Specs Side by Side

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

This page puts .300 RUM and .300 PRC side by side using only our own ammo guides, .300 RUM ammo (5 loads) and .300 PRC ammo (10 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 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 .300 RUM and .300 PRC guides. Pressures are as SAAMI lists them.

Measure	.300 RUM	.300 PRC
SAAMI name	300 REMINGTON ULTRA MAGNUM [300 REM ULTRA MAG]	300 PRECISION RIFLE CARTRIDGE [300 PRC]
Drawing issued / revised	01/07/1999 / 05/26/2022	06/13/2018 / 02/17/2022
Maximum average pressure (transducer)	65,000 psi	65,000 psi
Crusher pressure	Not established	Not established
Cartridge overall length	3.450 in min to 3.600 in max	3.575 in min to 3.700 in max
Case length	2.850 in (−.020)	2.580 in (−.020)
Bullet diameter (as SAAMI prints it)	.309 in (−.003)	.3084 in (−.0030)
Bore / groove diameter	.300 in / .308 in	.300 in / .308 in
Twist and grooves	1 in 10.00, 6 grooves (marked optional)	1 in 8.50, 6 grooves (marked optional)
SAAMI reference velocity	Not yet verified (the PDF text does not clearly pair each weight with its velocity)	2,800 fps for a 225 gr bullet, measured 15 feet from the test barrel
SAAMI velocity test barrel	24 in standard rifle test barrel (SAAMI’s general statement; not among its listed exceptions)	24.000 in (±.010) with 6 grooves and a 1:8.50 twist (SAAMI velocity and pressure test barrel)

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	.300 RUM loads in our table	.300 PRC loads in our table
Remington	test barrel not listed: 3 loads, 150 to 180 gr, 3,175 to 3,450 fps	—
Hornady	24 in test barrel: 2 loads, 180 to 220 gr, 2,910 to 3,200 fps	24 in test barrel: 5 loads, 165 to 225 gr, 2,810 to 3,200 fps
Federal	—	test barrel not listed: 2 loads, 210 to 212 gr, 2,850 to 2,860 fps
Berger	—	26 in test barrel: 3 loads, 205 to 245 gr, 2,720 to 2,985 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	.300 RUM	.300 PRC
Hornady Outfitter	180 gr CX® Outfitter®, 3,200 fps, 4,093 ft-lb, 24 in test barrel, item 82084	190 gr. CX® Outfitter®, 3,000 fps, 3,797 ft-lb, 24 in test barrel, item 82164
Hornady Precision Hunter	220 gr ELD-X® Precision Hunter®, 2,910 fps, 4,136 ft-lb, 24 in test barrel, item 8209	212 gr ELD-X® Precision Hunter®, 2,860 fps, 3,850 ft-lb, 24 in test barrel, item 82166

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 (transducer) (SAAMI establishes no crusher pressure) for .300 RUM and 65,000 psi (transducer) (SAAMI establishes no crusher pressure) for .300 PRC. Source: ANSI/SAAMI Z299.4.
If bullet weight is your question: The .300 RUM loads in our table run from 150 gr (Remington Premier Scirocco 27950) to 220 gr (Hornady Precision Hunter 8209). The .300 PRC loads in our table run from 165 gr (Hornady American Whitetail Tipped 82163) to 245 gr (Berger Elite Hunter 55020). Sources: those maker pages.
If you want to see the printed velocities: the slowest and fastest muzzle velocities in our table: for .300 RUM: 2,910 fps, 24 in test barrel (Hornady Precision Hunter 8209) and 3,450 fps, test barrel not listed (Remington Premier Scirocco 27950). For .300 PRC they are 2,720 fps, 26 in test barrel (Berger Elite Hunter 55020) and 3,200 fps, 24 in test barrel (Hornady American Whitetail Tipped 82163). 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 2.850 in (−.020), cartridge overall length 3.450 in min to 3.600 in max for .300 RUM; and case length 2.580 in (−.020), cartridge overall length 3.575 in min to 3.700 in max for .300 PRC. Check the cartridge named in your rifle’s manual or marked on its barrel. Source: ANSI/SAAMI Z299.4.

Not yet verified

The .300 RUM guide has 5 loads (Remington and Hornady only) and the .300 PRC guide has 10, so load counts and ranges are not a measure of how many loads exist; they only reflect what is in our tables.
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 .300 RUM 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 .300 RUM ammo and .300 PRC ammo, plus .300 Win Mag ammo, .300 WSM ammo, .300 Win Mag vs .300 PRC, 7mm PRC vs .300 PRC, 6.5 PRC vs .300 PRC, 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 .300 RUM and .300 PRC?

SAAMI lists 65,000 psi (transducer) (SAAMI establishes no crusher pressure) for .300 RUM and 65,000 psi (transducer) (SAAMI establishes no crusher pressure) for .300 PRC, 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, .300 RUM or .300 PRC?

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 (.300 RUM ammo and .300 PRC 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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