.338 RCM Load Data & Reloading Guide

Rifle

Also known as: .338 Ruger Compact Magnum

About .338 RCM

The .338 Ruger Compact Magnum, or .338 RCM, was introduced by Ruger and Hornady in 2008 as part of their collaboration to offer powerful cartridges in a shorter, more compact form, particularly suitable for shorter-action rifles. Developed from the .375 Ruger parent case, the .338 RCM was designed to deliver magnum performance in a standard length action, making it an appealing choice for hunters seeking a powerful cartridge that doesn't necessitate an oversized rifle.

The technical characteristics of the .338 RCM include a rimless, bottleneck case design with a case length of 2.10 inches and an overall length of approximately 2.83 inches. It is ballistically similar to the .338 Win Mag but achieves this performance with a smaller case, a testament to the modern powder chemistry employed. Standard rifling twist rates for this caliber are usually 1:10 inches to stabilize the heavier .338-inch diameter bullets, which generally range from 180 to 250 grains.

Ballistic performance wise, the .338 RCM can drive a 225-grain bullet over 2800 feet per second, offering substantial energy suitable for large and medium game hunting. The shorter case allows for efficient combustion, translating to excellent on-game performance and manageable recoil. The versatility of bullet weights also accomodates varied hunting requirements, from deer to elk and moose.

For reloaders, the .338 RCM offers several noteworthy advantages. Its efficient case design uses powder capacity effectively, which means reloaders can achieve desired performance using less powder compared to larger magnum cases. The availability of high-quality, wide-ranging bullet options to match specific needs and preferences further enhances its appeal. Additionally, being a short-action cartridge, it facilitates quicker cycling in compatible rifles, an advantage in dynamic hunting scenarios.

Technical Drawing

.338 RCM cartridge dimensions, C.I.P.L1 = 39.83 mm, L2 = 43.04 mm, L3 = 51.18 mm, L6 = 72.14 mmL1 = 39.83 mmL2 = 43.04 mmL3 = 51.18 mmL6 = 72.14 mm60.4°

Based on C.I.P., the max. allowed case length is 2.015 in / 51.18 mm, the max. cartridge length is 2.840 in / 72.14 mm, and the max. allowed pressure is 62,366 PSI / 4,300 bar.

Technical Specifications

Maximum Pressure:62366 PSI / 4300 bar
Case Volume:71 Grains of Water
Primer Size:Large Rifle (LR)
Safety Standard:C.I.P. (Datasheet)
Bore Area:56.95 mm²
Barrel Diameter:0.338" / 8.6 mm
L1:1.568" / 39.83 mm
L2:1.694" / 43.04 mm
L3:2.015" / 51.18 mm
L6:2.840" / 72.14 mm

Start Calculating to Develop your own Load Data for .338 RCM

Use our professional ballistics calculator to develop safe and accurate load recipes for .338 RCM.

Start Calculating

Standard Load Data — .338 RCM

Select your desired cartridge and bullet weight below to access the corresponding load table. From there, you can choose any listed load recipe and transfer it directly into the ballistics calculator for further refinement, optimization, and precision tuning.

All
165 gr
175 gr
180 gr
200 gr
210 gr
225 gr
250 gr
275 gr

Frequently Asked Questions

The maximum pressure for .338 RCM is 62,366 psi | 4,300 bar.

.338 RCM typically uses a Large Rifle (LR) primer.

The case capacity of .338 RCM is approximately 71 grains of water (H₂O).