AR-10 – .300 RSAUM

(1 customer review)


AR-10 – .300 RSAUM

Step 2: Customize Barrel Options

  • 12″ Gas Tube + $12.00
  • 14″ Gas Tube + $35.00

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SKU: AR10300RSAUM01 Category: Product ID: 3458


The .300 RSAUM (RSAUM stands for Remington Short Action Ultra Magnum) is a cartridge developed by Remington Arms Company for use in hunting rifles. It is a relatively new cartridge, having been introduced in 2001. It is based on the .375 Remington Ultra Magnum case, which has been necked down to accept a .30 caliber bullet. It is intended to be used in short-action rifles, which are characterized by having a shorter bolt travel than long-action rifles.

The .300 RSAUM is intended to provide a high-performance cartridge with good ballistics and moderate recoil, making it suitable for hunting medium to large game at long ranges. It is capable of shooting bullets weighing from 115 to 220 grains, and can achieve velocities of up to 3,700 feet per second (1,128 meters per second). It is typically used with a 1:10 twist rate barrel, which is suitable for stabilizing the wide range of bullet weights that can be used with this cartridge.

In terms of performance, the .300 RSAUM is similar to other .30 caliber magnum cartridges, such as the .300 Winchester Magnum and the .300 Remington Ultra Magnum.

Turnaround Time:

Wait time for complete assemblies is 2-6 weeks.

Compatible with Armalite and DPMS platform rifles.

***Please make sure to use a DPMS style BCG.***

Try our Cerakote “Stainless” finish. It looks identical to bead blast, but doesn’t soak up oils or scratch easily.


If you placed an order via credit card, the fees charged to us by our merchant account will be deducted from your refund.
Custom barrels are warrantied but not subject to full refunds.

1 review for AR-10 – .300 RSAUM

  1. COLIN KULAS (verified owner)

    Bought a 22″ socom barrel, had to clean the chamber using twice Shot reloads but after that runs great, very accurate most break in was unnecessary very clean rifling

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