Blue Dot + 500 Linebaugh

Cartridge: 500 Linebaugh

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

Powder: Blue Dot 18.0 grains, individually weighted

Bullet: 420gr Hunter’s Supply

Primer: CCI 350 Large Pistol Magnum

LabRadar series: 82

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

Velocity: 1180 fps average (7 shots)

Spread: 1193 – 1171 = 22fps

Std Dev: 7 fps (7 shots)

Drag Coefficient: -1.56 fps/yard over first 60 yards

Notes: Taffin Test data shows 18-20 grains of Blue Dot for “LBT #512.440 LFN (445 Grains)” with 18 grains giving “1037fps from a 5 1/2″ barrel.”

A LOT of recoil, but noticeably less than 525grain @ 980fps load. Lot of smoke. Low flash. I had poor accuracy, but I attribute it to poor control — I hadn’t shot this big of a bore in a while, and the smoke made it difficult to see POI corrections. No signal on bullet pull — I single loaded.

Primers were starting to look flat. No unburned powder. I am not comfortable increasing this charge without more data, and recommend starting lower.

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TrailBoss + 500 Linebaugh

Cartridge: 500 Linebaugh

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

Powder: Trail Boss 2.2cc Lee dipper ≈ 9.4grains ± 0.2

Bullet: 420gr Hunter’s Supply

Primer: Winchester WLP

LabRadar series: 81

Shooting Record: 5 shots, 4/11/2017 @ Sunnyvale Rod & Gun, between 8 and 9 PM

Velocity: 768 fps

Spread: 778.6 – 757.4 = 21 fps

StdDev: 8.12fps

Drag Coefficient: -0.56 fps/yard over first 60 yards

Notes: Recoil was very controllable, no pain at all, I could make 100 yard hits repeatably. Winchester WLP primer helps identify light loads.

Although very slow, 420 grains × 768 feet per second = 240 grains × 1,344 feet per second, which approximates 44 magnum factory ammunition. And there was much less muzzle blast than with a 44 magnum. I was fortunate enough to be able to setup my chronograph at the 100 yard steel, and the LabRadar indicates that velocity-loss was pretty good for a pistol order of 1 fps lost for 6 feet of travel.

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I only got data to 60 yards. But extrapolating to 100 yards, the slug would still be moving at about 710fps — still a “Power Factor” of ~300.

Blue Dot + 45 Colt

Bottom line: 👎 in this caliber. There are more consistent powders for moderate 45 Colt loads. There are safer powders for heavy loads. I’ll finish the rest of the canister in 500 Linebaugh or 45 ACP.

Cartridge: 45 Colt

Firearm: Ruger Blackhawk, 5.5″ Barrel

Powder: Blue Dot 13gr±0.5 (high variation from using rifle-insert in measure)

Bullet:260gr Lyman #454424 from Matt’s Bullets

Primer: Rem 2½ Large Pistol

LabRadar series: S61

Shooting Record: 2017-03-07, evening, approx 55 Fahrenheit, 12 shots

Velocity (12 shots): Average 1060fps, ES 1087-1015=72fps, StdDev 22.4fps

Notes: stiff recoil — not pleasant, but not yet painful with gloves on. Lots of smoke.

Charge was max for 14kPSI with 260 grain jacketed per Alliant data. Note that charge is above max (by 0.1 grain) for 250gr Lead SWC in Speer #12. Assume it is +P and unsafe, until proven otherwise. QuickLOAD predicts 921fps @ 13.7kPSI. But clearly we got more than that, so something’s up! I tried estimating the pressure by increasing the powder charge in QuickLOAD until I got a velocity of 1060fps, which happened at an estimated 19kPSI.


Bullet: 230 grain “Softball!” (actually Brinell 18) Hi-Tek coated from Missouri Bullet Co

LabRadar series: S62

Other details identical as “S61” above.

Velocity (6 shots): Average 1053fps, ES 1086 – 1023 = 63fps, StdDev 22.3fps

Notes: Recoil was noticeably less than 260 grain load, much much less smoke.


Brass: Starline 1x fired

Primer: Rem 2½ Large Pistol

Powder: Blue Dot 12.9gr (Indv. Weighed)

Bullet: 250gr Lead SWC (Speer #4684)

Crimp: Lee Factory Crimp (moderate)

LabRadar Series: 86

Velocity: 1028 nominal, 1019 actual. ES 1043 – 996 = 47fps, StdDev 14.8fps (13 shots)

Notes: Speer LSWC Bullets are very consistent, ±1 grain or less. Charge is maximum in Speer #12. I took my time weighing each charge, so I could test if Blue Dot is a consistent powder — since my early loads above might have just shown inconsistent powder-measuring + variability in casting.

Die Adjustment Cheat Sheet

1/TPI = vertical distance traveled (inches) in one turn. Always round that number up, so you seat too shallow. It’s easier to add more turns than to pull the bullet and start over.

Standard dies are 7/8-14 = 1/14″ per turn 0.01″ per 1/8 turn is a healthy over-estimate.

Lee seater stems: use +0.015″ per 1/4 turn to estimate. Actual number is 18TPI and closer to 0.1388…89″.

Redding 3BR Pistol Insert

Whole numbers probably represent 0.01″ (0.254mm) of micrometer travel. Micrometer spindle hole is approx. 0.314(5)” when measured with calipers. A .312 (Likely 5/16″) insert enters hole. 8mm = 0.314961″ is a working metric approximation for the hole’s diameter.

The empirically-derived models I have for predicting a needed setting with a new powder are:

grains = insert_number * 0.0115 * VMD ^ -1.039 + 0.29.

insert_number = (grains – 0.29) / (0.0115 * VMD ^ -1.039)

grains = insert_number * (0.2627 – 1.249*VMD) + 0.29

insert_number = (grains – 0.29)/(0.2627 – 1.249*VMD)

I still haven’t tried them with a new powder.