Buffalo Bore 45 Auto Rim 255gr Hard Cast – Solid Standard Pressure Load

Description

The Buffalo Bore 45 Auto Rim 255gr Hard Cast is a heavy cast load for a cartridge most people have never handled. A 255 grain hard cast flat nose at 850 fps produces roughly 409 ft-lbs, at standard pressure, in a case designed so that 45 ACP revolvers can be loaded without moon clips. Twenty rounds per box, item 31A/20.

• Buffalo Bore 45 Auto Rim 255gr Hard Cast Overview
• 45 Auto Rim Hard Cast Ammo Ballistics
• Why The 255 Grain Flat Nose Revolver Bullet Works Here
• Specifications
• Which Revolvers Take This Standard Pressure 45 AR Load

Buffalo Bore 45 Auto Rim 255gr Hard Cast Overview

The 45 Auto Rim exists for a specific reason. When the American military chambered revolvers for the rimless 45 ACP during the First World War, the cases had no rim for the extractor to grip, so half moon clips were needed to hold and eject them. Remington solved it in 1920 by making a rimmed case of the same dimensions.

That is still its whole appeal. A Smith and Wesson or Colt 1917, or any modern 45 ACP revolver, will chamber and extract 45 Auto Rim without any clips at all. The rim is thick, which both locates the cartridge in the chamber and gives the extractor star something to push against, so a 255 grain flat nose revolver bullet loads and ejects like any other rimmed round.

The bullet in the Buffalo Bore 45 Auto Rim 255gr Hard Cast is cast from a hard alloy with a flat nose, so it does not deform on impact. At 255 grains it is heavy for the calibre, which gives it the sectional density that decides how deep a non expanding bullet goes.

45 Auto Rim Hard Cast Ammo Ballistics

409 ft-lbs at 850 fps is a solid figure for a standard pressure load in this case. A typical 230 grain 45 ACP round at 850 fps makes about 369, so the heavier bullet is buying you a useful margin at the same velocity.

Against the +P version of this same bullet, which runs 1000 fps for 566 ft-lbs, you are giving up roughly a quarter of the energy. What you gain is a load that asks nothing at all of the revolver.

Energy is the wrong lens for a non expanding bullet in any case. 45 Auto Rim hard cast ammo converts its energy into depth rather than into opening up, so the comparison that matters is against other things that drive straight through.

Why The 255 Grain Flat Nose Revolver Bullet Works Here

Hard cast is the sensible choice in a cartridge working at these velocities. Expansion costs penetration, and at 850 fps there is not enough speed in reserve to pay for both. A bullet that does not deform keeps all of its weight and all of its frontal area and simply keeps going.

The flat nose is what makes that depth useful rather than merely long. A round nose of the same weight will push tissue aside and leave a narrow track. A flat meplat crushes and cuts, leaving a full calibre hole with clean edges from entry onward.

At 0.452 of an inch you are starting with a wide bullet before anything happens. That is the quiet advantage of the 45 family, and 45 Auto Rim hard cast ammo keeps that full diameter all the way through rather than trading it for a bigger frontal area early on.

And it makes an old revolver genuinely useful again. A 1917 or a Model 25 loaded with this is a capable field gun rather than a curiosity, and a standard pressure 45 AR load asks nothing of the gun that it was not built to handle.

Specifications

Which Revolvers Take This Standard Pressure 45 AR Load

Check that your revolver is chambered for 45 ACP or 45 Auto Rim before ordering. The two cartridges share everything except the rim, and a 45 Auto Rim round will not fit a chamber cut for something else. It will, however, work in any 45 ACP revolver without clips.

Standard pressure means no special requirements, which is the reason to pick this over the +P version. Any sound 45 ACP revolver in normal working order is a candidate, including older guns you would not want to feed heavier ammunition.

Confirm your point of impact. At 255 grains this is considerably heavier than the 230 grain ball most of these revolvers were regulated around, so it will usually print higher at twenty five yards.

Expect cast bullet fouling on the cylinder face. That is normal and not a problem, though moon clip free revolver ammunition with a lubricated cast bullet does leave the gun looking dirtier than jacketed ammunition would.

Moon Clip Free Revolver Ammunition Availability

This moon clip free revolver ammunition is in stock and ready to ship from MAG5 Firearms, a family owned FFL dealer in Collegeville, Pennsylvania. Ammunition orders ship to most states, and local customers are welcome to pick up in the shop. If you need case quantities or the +P version, call us and we will check what our distributors have on hand.

Manufacturer details are on the Buffalo Bore site. For more velocity from the same bullet, see the 45 Auto Rim +P 255gr hard cast. For an expanding bullet, compare the 45 Auto Rim 200gr JHP, or browse our full ammunition selection.