Load data for .38 Special + .358 | 180gr | Rim Rock LBT-WFN Gas Check

.38 Special cartridge drawing
Rim Rock logo

Load Specifications

Bullet Manufacturer:Rim Rock
Bullet Weight:180 gr
Bullet Diameter:0.358"
Bullet Length:<<locked>>
Case Length (l3):1.145"
Cartridge Length (C.O.L.):<<locked>>
Case Capacity:23.1 Grains of Water
Primer Size:Small Pistol (SP)
Barrel Length:4"
Max. allowed Pressure:21,756 psi

Load data in caliber .38 Special with .358 | 180gr | Rim Rock LBT-WFN Gas Check bullet and 9 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.

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Max Load - Barrel Length: 4"

PowderChargeFRMaxP%V(0)z
ADI AP 100*²<<locked>>72%19,580 psi90%863 fps89.5%
Alliant Herco²<<locked>>68%19,189 psi88%837 fps99.6%
Baschieri & Pellagri 102 Pistol²<<locked>>68%19,043 psi88%781 fps100%
Hodgdon TrailBossᴾ<<locked>>100%17,042 psi78%719 fps100%
ReloadSwiss RS 14ᴾ<<locked>>100%15,780 psi73%722 fps100%
Rottweil P 806*²<<locked>>68%19,348 psi89%912 fps93.9%
SNPE Vectan BA7 1/2*²<<locked>>64%19,319 psi89%840 fps94.8%
Vihtavuori N32C Tin Star²<<locked>>76%19,203 psi88%735 fps100%
Vihtavuori N350²<<locked>>64%19,609 psi90%860 fps96.4%

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

Start Load - Barrel Length: 4"

PowderChargeFRMaxP%V(0)z
ADI AP 100*²<<locked>>64%15,577 psi72%781 fps85.2%
Alliant Herco²<<locked>>60%15,592 psi72%768 fps98.2%
Baschieri & Pellagri 102 Pistol²<<locked>>60%15,171 psi70%722 fps100%
Hodgdon TrailBoss²2.5 gr60%7,803 psi36%528 fps100%
ReloadSwiss RS 14²2.6 gr60%7,542 psi35%531 fps99%
Rottweil P 806*²<<locked>>60%14,518 psi67%814 fps88.7%
SNPE Vectan BA7 1/2*²<<locked>>60%16,969 psi78%797 fps92.8%
Vihtavuori N32C Tin Star²<<locked>>60%13,126 psi60%640 fps100%
Vihtavuori N350*²<<locked>>60%17,056 psi78%814 fps94.4%

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

* not dangerous but load has suboptimal powder burnt with possible characteristics such as extensive muzzle flash or inaccurate loads.

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

ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.

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

This overview compares 9 powders for .38 Special loaded with the .358 | 180gr | Rim Rock LBT-WFN Gas Check. Rottweil P 806 delivers the highest muzzle velocity at 912 fps; across all powders the maximum-charge window runs from 719 fps to 912 fps. Hodgdon TrailBoss gives the best case fill at 100 %, and 2 of the 9 powders fall inside the usable 80–100 % fill window.

Relative to the caliber's maximum pressure (150 MPa), the top charges use 73–90 %, leaving at least 10 % headroom. Hodgdon TrailBoss, ReloadSwiss RS 14 reach 100 % fill or more at maximum charge, so these are compressed loads: they need a long drop tube to seat cleanly and react sensitively to the case capacity of your own brass lot. ReloadSwiss RS 14, Hodgdon TrailBoss rank at the top here: for .38 Special with the .358 | 180gr | Rim Rock LBT-WFN Gas Check they combine a high case fill with complete burn and sit in the upper velocity band. As outliers, ADI AP 100, Rottweil P 806, SNPE Vectan BA7 1/2 burn incompletely and react more sensitively to barrel length and temperature. ADI AP 100, Alliant Herco, Baschieri & Pellagri 102 Pistol 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.

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