45 “Cowboy” Special

45 Cowboy Special (or sometimes just 45 Special) is a 45 ACP case, with a 45 Colt rim. The 45 Colt rim is smaller than the rim on a 45 Auto Rim. This lets it feed in many cowboy-action guns and use common 45 ACP load data. The smaller case-capacity means better performance with light loads, which is why I am interested in it. Starline now sells this brass to anyone (when I started this project the brass could only be had by buying the factory ammunition).

Factory Ammunition

👎 for position sensitivity, iffy chambering in 45 ACP/AR chambers.

I found a source for factory “American Cowboy Ammo” .45 Special. Specifications: “180 Grain Round Nose Flat Point” at 475 feet per second. I disassembled a loaded round and the bullet weighed 183.5 grains actual, over 4.4 grains of mystery powder. Unfortunately the factory rounds would not reliably chamber in my Ruger Blackhawk 45 ACP cylinder. I believe they were hanging up on the bullet nose. Only about half would fit in an EGW chamber gauge. Rounds that fit would not always chamber. Everything chambered fine in a 45 Colt cylinder.

Firing Record on 3/7/2017 at Sunnyvale Rod & Gun ~ 55℉ outside

Firearm 5.5″ Ruger Blackhawk with a 45 Colt cylinder

LabRadar Series: 68

Velocity: 485fps avg (555,513,526,472,576,347,450,435,488)

Spread: 576 – 347 = 229fps

Std Dev: 69.45 fps (9 shots)

Approximate Drag Coefficient: -0.64 fps/yard

Notes: Very light recoil, very quiet report, but significant unburned powder. Power Factor ~90 or only double the recoil of a .22lr.

Update: very position sensitive. I fired off the last of them, without a chronograph. When tipping the gun up before each shot, I didn’t get any unburned powder. Otherwise I got enough unburned flakes in the chambers that they had to be cleaned before longer 45 Colt ammunition would chamber.

Hand Loads

After firing the factory ammunition I uniformed the flash holes on the brass.

Bullets: 165 grain DEWC from Matt’s Bullets (Seated Flush by using an expander die, taper crimp in separate step.)

Primer: Rem 2 1/2

Powder: 0.7cc (Lee Dipper) Trail Boss

Brass: 1x Fired

Firearm 5.5″ Ruger Blackhawk with a 45 ACP cylinder

Velocity: 764fps

Spread: 784-748.5 = 35.5fps

Std Dev: 13.44 fps (6 shots)

LabRadar Series: 71

Notes: Clean burning. Clean holes. Mild recoil, but not recoil-free (~125 PF).

165 grain DEWC from Matt’s Bullets, seated flush, taper crimp. Fired in a 5.5″ Ruger Blackhawk with a 45 ACP cylinder. Velocity in feet per second.
Avg Vel Spread StdDev N Charge Primer LabRadar # Notes
766 799-747=52 20.5 6 3.0 Red Dot Rem 2 1/2 S97 Smelly
764 784-748.5=35.5 13.44 6 0.7cc Trail Boss Rem 2 1/2 S71 Accurate and good holes
591 615-546=68 30.4 5 0.5cc Trail Boss Rem 2 1/2 S99 Smelly
517 554-494=60 32 3 2.0gr Clays WLP S98 “Crackling” burning powder in air. Some holes were not clean. Some shots were silent with no hole, but clear bore.
411 6 3.1 3 1.5gr Clays WLP S100 No crackeling
580 603-551=52 16.9 12 2.0gr TiteWad (3BR #18) WLP S104 Unburned powder in case
467 480.5-452.5=28 14 3 1.5gr TiteWad (3BR #15.25) WLP S105 Unburned powder in case

525 Grain 500 Linebaugh

Cartridge: 500 Linebaugh

Firearm: Converted Ruger Blackhawk, 7.5″ Mag-na-ported Barrel

Powder: Accurate #9, 18.2 grains, individually weighted

Bullet: 525 grain WFNGC (Cast Performance)

Primer: CCI 350 Large Pistol Magnum

LabRadar series: 83

Shooting Record: 4/12/2017 @ Sunnyvale Rod & Gun

Velocity: 988, 990, 985

Spread: 6fps

Drag Coefficient: -0.68±0.7 fps/yard over first 60 yards

Notes: lots of recoil.

The “Geezer Load”

While looking for very soft-shooting 45 ACP loads, I saw “The Geezer Load” recommended a few times.

“So, here’s the scoop on the Geezer Load. Using mixed cases, with Winchester large pistol primers, and
Berry’ 185gr. HBRN bullet, a charge of 4.3-4.4 grains of Hodgdon’s Clays gives a velocity 758fps. The finished
rounds are loaded to an OAL of 1.250” and are crimped to .468”. The load is as close to 100% reliable
as it can be in my full size 1911 Government model pistols when they are run with 16lb. recoil springs.”
John Markwell

I double-checked a second source for safety. Hodgdon says that a Fed 150 Primer + Winchester brass + 185 GR. HDY JSWC + COL 1.135″ gives:

4.5gr Clays 855fps @ 14,500 CUP

4.9gr Clays 981 @ 17,000 CUP

I did: Mixed “Brass Guys” brass, Winchester WLP, 4.3 grains of Clays (first individually weighed, then #45 on the Redding 3BR), Berry’ 185gr. HBRN, OAL of 1.2650″, to match the OAL of Magtech 230 grain hardball. I used a lighter crimp. I figured that I could always seat deeper or add more crimp later if needed.

Firearm: Les Baer 5″ 1911

Date/Location: 5/13/2017 at approx 7:30 PM at Sunnyvale Rod & Gun Club

LabRadar Series: 92

Velocity: 755 fps avg (777, 713, 742, 776, 755, 739, 691, 797, 762, 733, 808, 773)

Spread: 808 – 691 = 117fps

StdDev:33.9 (12 shots)

Notes: Did cycle the the firearm, although I may try a shorter OAL next time, since with some magazines the feel of letting the slide down could have been smoother. Somewhat dirty — I will consider upping the charge for a better chamber-seal if there is gas blow-back. Power-factor looks about equal to 9mm. The spread is unfortunate. Pretty neat that my average speed was so close to Markwell’s figure.


Hodgdon Clays A very fast shotgun/pistol powder with a narrow velocity range that is optimized for clean and light-recoiling target loads.

Bottom line: 👍 so far.


  • Bulky (low density, high case-fill, only 14 ounces in a “1 pound” container).
  • Good metering in Redding 3BR.
  • Small charges means a can lasts a long time.
  • Load data available for different calibers.
  • Clean burning and good Std Dev possible with light felt recoil.
  • Powder does not want to stick to plastic if accidentally left in a hopper overnight


  • Narrow range of safe charges.
  • Can’t make more powerful ammunition.
  • “One Pound” can holds 14 ounces.

Density (per Lee dipper chart) 6.8 grains/cc (0.14620 VMD).

Redding 3BR Pistol Insert

pistol_insert_number ≈ Grains/0.0938 – 1

Grains Thrown ≈ 0.0938(pistol_insert_number + 1)

Pistol Insert # Grains Thrown 10x Throws (Grains)
35 3.4 33.3 (variable)
31 3.0 30.2
41 3.9 ???
42 4.05 ???
45 4.3 ???
48 4.5 44.9
50 4.8 ???

Hodgen Universal

Hodgdon Universal “…handles the broadest spectrum of cartridges”. Sometimes called Universal Clays. It is the “Clays” (cleaner burning) branded version of the classic propellent Unique.

Bottom Line: Good, but I haven’t found a reason to buy it again.

There’s no niche it fills for me. The flipside of being universal is that everything it does another powder does.


  • Lots of load data for many different cartridges.
  • Good for heavy / “light magnum” loads in pistol calibers.


  • Lots of unburned powder at light/starting loads.

Density (per Lee dipper chart) 9.1 grains/cc

Redding 3BR Pistol Insert

Grains Thrown ≈ 0.115 × pistol_insert_number + 0.34

Pistol # ≈ (grains – 0.34) / 0.115

Pistol Insert # Grains Thrown 10x Throws (Grains)
20 2.6 26.1
44 5.5 53.6
47 5.6 57.3
48 5.8- 58.2
50 6.1 60.4
55 6.6 66.0
60 7.2 71.1
99 11.7 116.8

Pink Bullets in 45 ACP

Bullet: 200 GR RN Polycoat Bullet from Eggleston Munitions in Pink.

Primer: Rem 2 1/2

Powder: 1.0cc Trail Boss ≈ 4.4 ± 0.2 grains

Cartridge Overall Length: 1.240″

Brass: Mixed 5x fired

Firearm 5″ 1911; Les Baer

Velocity: 774 fps (10 shot avg)

Spread: 804-734 = 70fps

Std Dev: 25.26 fps

LabRadar Series: 69

Notes: 👍 Unfortunately the pink bullet seems to be discontinued. Or only sometimes available. The coating did flake more than I’d like in shipping, leaving spots of exposed lead. Weight was pretty consistent, 200 – 203 grains.

Mild recoil. Quite report. Still cycled a couple 1911s.

Their load data shows 1.225″ COL for 200 GR RN Polycoat Bullet. I initially had a longer OAL of 1.255″, to be conservative about pressure. This shot fine in the one and only 1911 I tested, but after acquiring a chamber-gauge, I realized the rounds did not chamber in it. Seating deeper to (1.240″ COL) fixed the problem. I also crimped aggressively, but the COL was the true fix.

Powder: 5.8gr H. Universal

Velocity: 864fps avg

Spread: 911 – 809 = 102fps

Std Dev: 37 fps (12 shots)

LabRadar Series: 91

Notes: 👎 Stronger recoil than Trail Boss, but noticeably less than standard 230 grain loads.