Starline .455 Brass 0.76" vs. .455 Colt-Eley-Mk1 0.86"

[Outpost75]

This week I am casting bullets for my Colt New Service .455 Eley from the new Accurate mold 45-264H, to load in my newly received Starline .455 Mk2 cases.

Starline .455 Mk2 brass is 0.76" long, vs. 0.86" for Dominion .455 Eley and .455 Colt cases.

Accurate 45-264H was designed with the absolute minimal 0.25" seating depth, to maintain powder capacity and reduce pressure in the shorter case. It also features a 0.1 wide, full-diameter front driving band above the crimp groove. This aids cartridge alignment in the chambers when using the shorter Starline, Fiocchi and Hornady Mk2 cases in longer Webley military and Colt New Service revolvers manufactured with long chambers intentionally dimensioned for the longer Mk1 (Colt-Eley) case, so that those WW1-era revolvers could fire either round.

The shorter Mk2 case was adopted in 1897 to reduce excess free airspace in the case to improve ballistic uniformity when used with smokeless powder. The correct powder charge to use in Mk2 Starline cases with this bullet is 3.5 grains of Bullseye. This matches the 625+/- 25 fps velocity of the WW2 era Mk2z service load, an example Kynoch (1942) FMJ load being shown in the photo below, at left.

The center ctg. in the photo is a .455 Eley with Accurate 45-290H bullet assembled in a 0.86" case, made by shortening Starline .45 Schofield brass to 0.87" and lathe-turning the rim. If this heavier bullet is to be fired in Webley top-break revolvers it should be loaded ONLY in the longer 0.87" case, UNLESS the powder charge is REDUCED to 3 grains of Bullseye. In the longer 0.86" length case which was pressure tested by Larry Gibson, the maximum recommended charge is 3.5 grains of Bullseye, which should not be exceeded.

Making the longer Colt-Eley-Mk1case from Schofield brass is recommended for those loading ammunition for older marks I through III of Webley revolvers which are proved for black powder only, so as to hold the full 21 grain black powder charge.

But for most users of Boer War era Webley MkIV and later Webleys, as well as the S&W .455 Hand Ejector and Colt New Service, buying Starline Mk2 cases is very much easier. This new Accurate 45-264H design mostly compensates for the shorter Mk2 case by reducing bullet seating depth to maintain powder capacity, reducing bullet jump and improving guidance of the bullet in its transition from case mouth to the cylinder throat. The large meplat will provide good crush characteristics with deep, straight-through penetration, at low velocities <700 fps where no expansion is expected.

My mold drops bullets as-cast from 12 BHN backstop scrap at .456" diameter and 262 grains. It fits my 1914 Colt New Service as-cast and unsized. The .425" long nose above the crimp precludes its use in the .45 Colt, as cartridge OAL would be 1.71". Cartridge OAL is 1.525" in .45 Schofield brass, 1.323 in .45 Auto Rim, 1.285" in .455 Colt and 1.185" in .455 Mk2, and this ogival wadcutter should have excellent potential for those classic .45s.

235998235999

[johniv]

Good info, thanks.

[ddixie884]

I know a lot of folks asked Star-Line to make the longer case, but they were adamant that the Mk II was the one they were going to use. Your solution to the problem looks like it will work. Thank you for sharing this info and I hope you enjoy the fruits of your labor.......

[rintinglen]

Buying Short Mk II brass beats the heck out of modifying 45 Colt brass rims and trimming them to length. Back in the very early eighties I went that route to feed a Webley MK IV (Just like Indy used in Raiders of the lost arc.). I used store bought 230 grain cast RN boolits over 4.0 grains of Red Dot, which shot OK but were probably a little too warm for what was then an 80 year old gun.

[Outpost75]

Range report, 3.5 grains of Bullseye or 3.7 grains of old 452AA, if you have any:

236227

[6string]

Hi,
I used to have a S&W 2nd model HE in 455. I was determined to get the most out of it, as it was going to serve as my CF revolver for bullseye matches at my club. Looking at it from the standpoint of working with a rifle of unknown chambering, I worked out the maximum chamber dimensions. The various 455 cartridges in my collection were all less than ideal. So, going with 45 Colt brass, I thinned the rims to give me near zero headspace, then trimmed to just short of maximum allowable case length. Reloading dies were a mix of 45 Colt and ACP. Priming was a challenge due to the thinner rim: most tools like the Lee Autoprime wouldn't fully seat the primer. But, I used one to get the job mostly done, then did the final seating with a press mounted Lee tool.
The effort was well worth it, though, as the old S&W turned out to be quite the shooter with "as cast" diameter SWCs.
I wrote up some of this on the S & W forum.
http://smith-wessonforum.com/s-w-hand-ejectors-1896-1961/581212-455-ammo-info-collectors.html

Jim

[smkummer]

This is good info. As of now I am riding on a high cloud with the 3 empty boxes of dominion 455 colt I found at a gun show. Older Lyman data with unique and Lyman’s 454190 gives me a respectable load in my 1916 New Service 455 eley. One would think Starline would have sold more cases if they made the longer length as it would be easily for those wanting shorter cases to simply trim.

[Outpost75]

This is good info. As of now I am riding on a high cloud with the 3 empty boxes of dominion 455 colt I found at a gun show. Older Lyman data with unique and Lyman’s 454190 gives me a respectable load in my 1916 New Service 455 eley. One would think Starline would have sold more cases if they made the longer length as it would be easily for those wanting shorter cases to simply trim.

Here is .455 load data from The Fouling Shot:

Table 1 - .455 Velocity Test Data
_________________________Velocity (fps), Sd ____Kirst Ctg. Conversion___”Rook Rifle”
_________________________Webley Mk VI 6” Bbl._Ruger ROA 7-1/2”______H&R 20”
_________________________Cylinder gap 0.018”__Cylinder gap 0.004”____Solid Bbl.
K42 Mk VIz 265-grain FMJ___537 fps, 29 Sd_____580 fps, 32 Sd________680 fps, 40 Sd

Handloads in Hornady .455 Mk II cases (0.77”) with Winchester LP primers

#452374 225-gr.5.0 Unique____648 fps, 24 Sd___716 fps, 11 Sd________814 fps, 14 Sd
MiHec 265-gr. HB 4.5 Unique___538 fps, 24 Sd___679 fps, 32 Sd________788 fps, 11 Sd
Accurate 45-260H 3.5 Bullseye__622 fps, 6 Sd____720 fps. 16 Sd________813 fps, 18 Sd

Handload in Starline .45 Schofield Case modified to .455 Mk I (0.86”)

Accurate 45-260H 3.5 Bullseye__546 fps, 16 Sd___641 fps, 9 Sd_________753 fps, 11 Sd



Table -2 .455 Pressure Test Data - Submitted by Larry Gibson, Lake Havasu, AZ

Firearm – T/C Contender .45 Colt 10” with strain gage interface to Oehler M43 Ballistic Test System, All test loads assembled in Starline .45 Schofield brass shortened to 0.87” length and rims turned, Winchester LP primer, weighed charges of 3.5 grains Alliant Bullseye throughout.

Accurate 45-240H (252grs., 10 BHN) .452”, OAL 1.29” –639fps, 11,400 psi max.*
• Only one shot recorded a high enough pressure to measure on the strain gage

Accurate 45-260H (269grs., 10 BHN) .452”, OAL 1.30” –648fps, 14Sd, ES 42, 11,800 psi, ES 900 psi

Accurate 45-290H (295grs., 10 BHN) .452”, OAL 1.298” –672fps, 11Sd, 32 ES, 12,600 psi, ES 1100 psi

Expected velocity drop in 6” barrel revolver est. -100 to 150 fps, depending upon cyl.gap.