Bring true big-bore, penetration-first performance to a classic revolver cartridge with Buffalo Bore Ammunition Standard Pressure “Strictly Business” .45 Auto Rim 255gr Hard Cast Flat Nose (HCFN). Built for shooters who run .45 Auto Rim in revolvers (often in rugged, practical platforms where reliability and straight-line performance matter), this load is designed around a heavy 255-grain hard cast flat nose bullet that prioritizes deep penetration, consistent tracking, and dependable function—all while staying standard pressure. Packaged 20 rounds per box and 12 boxes per case (240 rounds per case), this model is Item 31A20 with UPC 651815031019.
Why .45 Auto Rim still matters
The .45 Auto Rim cartridge was created to allow .45-caliber revolvers (notably those originally designed around .45 ACP) to run reliably without moon clips. For many revolver shooters, it remains a practical option that combines big-bore authority with straightforward revolver function. If you carry or train with an Auto Rim revolver, ammunition choice matters—especially when you want a load that does more than punch paper.
This Buffalo Bore offering is built for shooters who want a serious working load in .45 Auto Rim—one that emphasizes what the cartridge can do best: launch a heavy bullet with authority and predictability.
255gr Hard Cast Flat Nose: penetration-first, straight-line performance
The centerpiece of this load is the 255 grain hard cast flat nose bullet. This style of projectile is chosen for a very specific reason: it tends to penetrate deeply and maintain a consistent path, rather than relying on expansion. The flat nose (meplat) helps the bullet “work” on target, while hard cast construction helps it maintain shape for consistent performance.
This bullet style is popular among shooters who prioritize:
Deep penetration over expansion
Consistent performance through tissue and bone
Predictable results in a wide range of conditions
A heavy-for-caliber bullet that carries momentum
If you’re searching for terms like “Buffalo Bore 45 Auto Rim hard cast”, “255gr flat nose Auto Rim”, or “31A20 651815031019”, this is the exact configuration that matches.
Standard pressure: big-bore performance without +P variables
Buffalo Bore lists this load as standard pressure, which is important for shooters who want strong performance while staying within typical pressure expectations for the cartridge. Standard pressure ammunition can offer practical advantages, including:
Broad compatibility with appropriate .45 Auto Rim revolvers
Manageable recoil relative to higher-pressure options
Consistent handling characteristics for training and field use
(Always confirm your firearm is in safe operating condition and appropriate for the ammunition you choose.)
Ideal uses: field carry, outdoors utility, and serious revolver work
This load is a strong fit for:
Outdoor carry where penetration is often prioritized
Ranch/property use where a revolver is a working tool
Hunting backup and general field-sidearm roles
Revolver shooters who want a dependable heavy load for practical use
It’s also a smart option for shooters who want to standardize on a single heavy, penetration-focused load for their Auto Rim revolver—zero it, test it, and stick with it.
Packaging designed for stocking and consistency
Buffalo Bore keeps it straightforward:
20 rounds per box
12 boxes per case
240 rounds per case
That’s ideal for function testing, point-of-impact verification, and maintaining consistent inventory for carry rotation or field readiness.
SEO-friendly product identifiers and specs
Brand: Buffalo Bore Ammunition
Line: Standard Pressure / Strictly Business
Cartridge: .45 Auto Rim
Bullet Weight: 255 grain
Bullet Type: Hard Cast Flat Nose (HCFN)
Rounds per Box: 20
Boxes per Case: 12
Rounds per Case: 240
Item / SKU: 31A20
UPC: 651815031019
The bottom line
If you want a serious .45 Auto Rim load that emphasizes deep, straight-line penetration with a heavy-for-caliber bullet—without stepping into +P territory—the Buffalo Bore Standard Pressure Strictly Business .45 Auto Rim 255gr Hard Cast Flat Nose (31A20 / 651815031019) is built for the job. It’s a purpose-driven big-bore revolver round designed for shooters who carry their wheelgun to work, into the woods, or anywhere “strictly business” performance matters.
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