Rim Rock Load Data
Our Rim Rock load data covers 96,549 load recipes for 217 bullets and 100 calibers. Find all bullets and reloading data below and compare the performance of different powders for each bullet and caliber combination side-by-side.

Rim Rock Bullets is a family-owned and operated ammunition manufacturer renowned for producing high-quality cast lead bullets. With a commitment to craftsmanship and customer service, the company takes a hands-on approach to every aspect of its operations—from production to personal communication. Owners Frank, Susan, and Frankie Brown pride themselves on treating customers like family, ensuring responsive service and maintaining consistent stock availability.
What sets Rim Rock Bullets apart is their dedication to precision casting and material quality. Each bullet is made from virgin lead alloy, carefully mixed with optimal amounts of tin and antimony for enhanced hardness, consistency, and accuracy. By sourcing lead in massive quantities—60,000 pounds at a time—the company ensures every batch maintains the same reliable composition, resulting in bullets that perform predictably shot after shot.
The manufacturing process emphasizes uniformity and consistency. Instead of alternating between calibers, Rim Rock dedicates production runs to a single bullet type at a time. For example, a .38/.357 158 grain SWC bullet might be produced on four machines for ten consecutive days—yielding more than 1 million identical bullets. This method ensures tight tolerances and consistent performance, making Rim Rock Bullets a trusted choice for target shooters, hunters, and reloaders alike.
With a focus on accuracy, availability, and exceptional service, Rim Rock Bullets continues to earn the loyalty of shooters across the United States. Their motto, "We are happy when our customers are happy," reflects a company culture deeply rooted in integrity, reliability, and customer satisfaction.
Bullets Covered
217 bullets
All Rim Rock Load Data
.45-70 Govt. + .458 | 405gr | Rim Rock RNFP Top Shelf
.45 Colt + .451 | 255gr | Rim Rock SWC
.45 ACP + .452 | 250gr | Rim Rock RNFP Top Shelf
.45 Colt + .451 | 250gr | Rim Rock RNFP
.45 ACP + .451 | 185gr | Rim Rock SWC
.44-40 WCF + .427 | 180gr | Rim Rock RNFP Cowboy
.45 Colt + .452 | 255gr | Rim Rock SWC Top Shelf
.44 Rem. Mag. + .427 | 240gr | Rim Rock RNFP Cowboy
.38 Special + .358 | 158gr | Rim Rock RN Cowboy
.45 Auto Rim + .452 | 255gr | Rim Rock SWC Top Shelf
.32-20 Win. + .313 | 100gr | Rim Rock RNFP Cowboy
.38 Special + .358 | 125gr | Rim Rock RNFP Cowboy
.357 Maximum + .358 | 180gr | Rim Rock LBT-WFN Gas Check
.45 ACP + .452 | 200gr | Rim Rock RNFP Top Shelf
.327 Federal Mag. + .313 | 100gr | Rim Rock RNFP Top Shelf
.45 Auto Rim + .451 | 255gr | Rim Rock SWC Top Shelf
.32-20 Win. + .313 | 100gr | Rim Rock DEWC
.32 H&R Mag. + .313 | 100gr | Rim Rock RNFP Cowboy
.357 Mag. + .358 | 155gr | Rim Rock DEWC
.32 S&W + .313 | 78gr | Rim Rock RN Top Shelf
.45 Colt + .451 | 185gr | Rim Rock SWC
.44 Rem. Mag. + .43 | 240gr | Rim Rock RNFP Top Shelf
.44 S&W Special + .427 | 200gr | Rim Rock RNFP Cowboy
.44 Rem. Mag. + .429 | 200gr | Rim Rock DEWC
About Rim Rock load data on XXL Reloading
This page collects every Rim Rock bullet we hold reloading data for, grouped by caliber and bullet weight. Each caliber and bullet combination links to a detail page with powder-by-powder load recipes: powder brand and type, start and maximum charge weight in grains and grams, case fill ratio, calculated peak chamber pressure, muzzle velocity and the barrel length the load was computed for.
Unlike a manufacturer's own tables, our Rim Rock data is generated with an inner-ballistics engine across the full powder range, so you can compare many powders side by side for the same bullet instead of the handful a single load manual prints. Charge weights, pressures and velocities are modelled consistently, which makes cross-powder and cross-caliber comparison meaningful when you work up a load.
Use the caliber and bullet-weight filters above to narrow the list, switch to the Bullets tab to browse the Rim Rock product range, and open any combination to see the full load table. All data is calculated reference data for experienced handloaders: always start at the minimum charge, work up carefully in your own rifle, and cross-check against current published data before firing.