Load data for .44 S&W Russian + .427 | 240gr | Rim Rock RNFP Cowboy

.44 S&W Russian cartridge drawing
Rim Rock logo

Load Specifications

Bullet Manufacturer:Rim Rock
Bullet Weight:240 gr
Bullet Diameter:0.427"
Bullet Length:<<locked>>
Case Length (l3):0.97"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:27.1 Grains of Water
Primer Size:Large Pistol (LP)
Barrel Length:4.5"
Max. allowed Pressure:14,504 psi

Load data in caliber .44 S&W Russian with .427 | 240gr | Rim Rock RNFP Cowboy bullet and 2 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ReloadSwiss RS 14 and Hodgdon TrailBoss.

Important Notice: DO NOT go below Minimum Charge or above Maximum Charge. Since we have no control over the equipment and components used, any responsibility and liability for the results achieved is rejected.

Only powders/loads that match the current filter criteria are displayed: max pressure of a load ≤ 90% of max. standardized pressure, fill rate ≥ 60% and propellant combustion ≥ 80%. Use the sliders above the tables to adjust these thresholds.

Charge: Powder weight in grains. Start with the minimum load and work up carefully.

FR (Fill Rate): Case fill as a percentage. Values above 100% mean compressed loads.

MaxP / %: Maximum chamber pressure in bar and as a percentage of the standardized maximum for this caliber.

V(0): Muzzle velocity in feet per second (fps) at the standardized barrel length.

z (Powder Burn): Estimated propellant combustion percentage at bullet exit.

A valid access license is required to use the Personalized Load Calculator.

You can find more information in our FAQ: How can I use the Personalized Load Calculator?

Max Load - Barrel Length: 4.5"

PowderChargeFRMaxP%V(0)z
Hodgdon TrailBoss<<locked>>88%12,720 psi88%692 fps100%
ReloadSwiss RS 14<<locked>>92%12,415 psi86%709 fps100%

Recommended = one of the top powders for this cartridge and bullet combination.

Start Load - Barrel Length: 4.5"

PowderChargeFRMaxP%V(0)z
Hodgdon TrailBoss²3.4 gr60%7,223 psi50%551 fps100%
ReloadSwiss RS 14²3.5 gr60%6,875 psi47%548 fps97.9%

Recommended = one of the top powders for this cartridge and bullet combination.

² fill rate low - you might want to consider using a filler to ensure proper ignition.

<<locked>> you need an access license to unlock this data.

This overview compares 2 powders for .44 S&W Russian loaded with the .427 | 240gr | Rim Rock RNFP Cowboy. ReloadSwiss RS 14 delivers the highest muzzle velocity at 709 fps; across all powders the maximum-charge window runs from 692 fps to 709 fps. ReloadSwiss RS 14 gives the best case fill at 92 %, and 2 of the 2 powders fall inside the usable 80–100 % fill window.

Relative to the caliber's maximum pressure (100 MPa), the top charges use 86–88 %, leaving at least 12 % headroom. ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for .44 S&W Russian with the .427 | 240gr | Rim Rock RNFP Cowboy they combine a high case fill with complete burn and sit in the upper velocity band. Hodgdon TrailBoss, ReloadSwiss RS 14 stay subsonic at start load. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.

← All load data