455 Webley MKII

[markalarson]

Hello you vintage hand loaders. I would like some load data from other than 'cartridges of the world' and 'loaddata.com'

Thanks in advanced

[Bigslug]

I'll try to remember to dig up the charges I've ended up with for my MKVI revolver tonight. Loading the MP copies of both the MKII (conical round nose) and MKIV (wadcutter) hollow based bullets.

I had a little confusion early on regarding whether the regulation charges were running closer to 600 or 700 fps. As best I could determine, the 700 was the older, black powder speed - possibly in the longer MKI brass. I concluded after some jug testing that 600-ish gives plenty of penetration and shoots close enough to the sights for "government work". The charges are sufficiently small that you'll want faster-burning propellants. Stay tuned.

[Larry Gibson]

Probably won't find a finer "treatise" short of a book.....

Tales From The Back Creek Diary

Modern Cast Bullet Fodder Safely Feeds Old Brit War Horses

Proper bullets and brass with prudent load development enable old .455 revolvers to soldier on…

C.E. “Ed” Harris, Gerrardstown, WV

“The revolver is… a weapon for quick use at close quarters… looked upon more as a defensive weapon than an arm of precision…for delivering a knock-down blow within the limits of its normal short fighting range… used instinctively… aligned and discharged as a shotgun is used on moving game, rather than being consciously sighted…” - [British] Textbook of Small Arms, 1929
A Brief History of Brit Revolvers and Ammunition:

Handguns with multiple revolving barrels date from the 16th Century. The invention of the percussion cap made the development of revolvers practical. Colt used a revolving cylinder and fixed barrel in the manner of older Collier flintlock revolvers, avoiding the necessity to independently prime each chamber and manipulate the pan cover. Colt’s design which incorporated a cylinder stop acting independently of the ratchet gear, enabled later Walker, Dragoon, 1851 Navy and 1860 Army revolvers to perform reliably in combat, the .44 calibers demonstrating adequacy to “take an enemy’s horse out from under him.”

British and Continental makers produced long-stroke, double-action revolvers. These were incapable of being independently cocked by the hammer until Adams, in 1851, produced a solid-framed revolver capable of either manually-cocked single-action, or trigger-cocked in double-action fire. During the Crimean War both Colt and Adams percussion “50-bore” revolvers were carried by British officers.

During the American Civil War, members of Mosby’s Confederate light cavalry guerillas carried multiple Colt revolvers. But as many as four handguns never equaled the firepower of then-developing repeating carbines, being limited by short range, necessitated by the revolver’s lower kinetic energy. Slowness of reloading revolvers remained the bane of the cavalry trooper until the development of metallic cartridges and reliable mechanical ejection in the 1870s.

The first self-extracting revolver issued by the British Army was the Enfield .442 rim fire, issued later in .450 centerfire. The Enfield proved unreliable in combat, due to its delicate mechanism and under-powered cartridge, attaining only 500 fps with its 225-grain hollow-based bullet. When the .450 was withdrawn it was replaced by the Webley Mk I, a 4-inch barreled “pistol,” firing the .450/476 cartridge, in August 1890. The Webley was produced in successive “Marks” I through VI. Of these only the Mark IV (Boer War Model) and later Mark V and Mark VI revolvers are suitable for safe use with Cordite or smokeless loadings. The earlier Marks I through III should be limited to black powder only.

Six main types of .455 ammunition were produced:
The .455 Webley Mk I had a case length of 0.88” and was introduced in 1891. It was loaded with a 265 grain lead, hollow-based, round-nosed bullet of 1:12 tin/lead, and 18 grains of black powder, lubricated with beeswax. A few experimental Mk I cordite cartridges were produced before the Mk II. The longer Mk I case was used for sporting, Boxer-primed, smokeless loads by CIL until the early 1970s.

Starting with the Mk ll, introduced in 1897, subsequent .455 British service cartridges were loaded in the 0.76” case to reduce excessive airspace to improve ballistic uniformity with smokeless powder. The Mk II 265 grain lead, round-nosed, hollow-based bullet resembled the nose shape of the Mk I, but with a shallower hollow base, reducing the bullet’s overall length to improve gyroscopic stability, with larger lubricating grooves. Its 6.5 grains of Mk I chopped Cordite produced 600 fps from a 6-inch barrel.

The Mk III cartridge, introduced in 1898, was the famous "Manstopper" bullet intended for police, civilian defense, and colonial use. It was a double-ended, 218-grain design, swaged of 1:12 tin/lead, having hemispherical cavities at each end—one to seal the barrel, the other to deform upon impact. It was loaded with 6.5 grains of chopped Cordite for 600 fps. Because it was not compliant with the Hague Convention of 1899, the Mk III was withdrawn in 1900 and the Mk II cartridge was reintroduced.

The Webley Mk IV, introduced in 1912, featured a solid, 220 grain, flat-nosed, hollow-based wadcutter, loaded with cordite propellant, producing 600 fps, its design objective intending to be more effective than the round-nosed Mark II, but without violating the terms of the Hague Convention.

The Mk V, introduced in 1914, was identical to the Mk IV, but formed from antimonial-lead-alloy recovered from salvaged storage battery plates, as a manufacturing expedient, to conserve tin as a critical wartime material. It was in use only from April through November 1914. Harder antimonial-lead bullets proved less than completely satisfactory, due to barrel leading. The Mk V was almost immediately withdrawn and the Mark II returned to service. Remaining Mk V cartridges were used up for training and target practice and remaining in-process Mk V marked cases were assembled with Mk II bullets.

The Mk VI cartridge, introduced in 1939, is the variant most commonly found, used during WW2. It has a 265-grain FMJ, hollow-based Hague-compliant bullet propelled either by 5.5–7.5 grains of chopped cordite, or alternately 5.5-6.0 grains of flake nitrocellulose, the powder charge being determined at the time of loading to produce 625 +/-25 fps. Cordite-loaded cartridges bore a "VI" in the head stamp, whereas nitrocellulose-loaded cartridges were marked "VIz". Although obsolescent by the end of WW2, the Mark VI cartridge continued to be made into the late 1960s by Kynoch to fill export contracts for Pakistan, Kenya and other export customers. Late production was produced with small size Berdan primers. Remington and Winchester produced .455 in both case lengths prior to WW2. CIL in Canada loaded .455 Colts into the 1970s. Hornady produced a limited run of Mk II ammo in 2008. Fiocchi is the only current occasional producer of .455 M k II cartridges, other than custom loaders.

Cautions for Feeding “Shaved” Webleys Converted to .45 ACP!
The .455 Webley has a maximum operating pressure (sample average) of 12,700 psi, whereas .45 ACP may run up to 19,900 psi. This means that when firing your imported surplus Webley, commonly modified to fire .45 ACP for the US market, every time you pull the trigger, you're re-proofing the gun!

Marks I through III of earlier Webley service revolvers were proofed only for black powder. While many converted Mk IV and later .455 Webley revolvers have survived repeated firing of .45 ACP ammunition, such treatment is equivalent to an accelerated endurance test, feeding the revolver a steady diet of proof loads. Such abuse is testimony to the sturdiness of these revolvers, because this practice certainly cannot be considered safe.

Cylinder throats of all original Webley revolvers I have measured were tighter than barrel groove diameter, typically .449-.451." Colts and S&Ws, usually have very large cylinder throats of .457-.459” with barrel groove diameters being .455-.457”. Forcing oversized bullets into tight cylinder throats increases chamber pressure dangerously, PARTICULARLY when bullets are full metal jacketed or cast hard! Safe results require SOFT lead bullets not exceeding 10 BHN, sized to fit the cylinder throats. Bullet weights from 230-270 grains are recommended to shoot to point of aim with fixed sights. I recommend that ammunition destined for “shaved” .45 ACP revolvers be assembled into .45 Auto-Rim cases for positive identification. Loads developed in stronger Colt and S&W .455 revolvers using larger bullet diameters and producing velocities over 700 fps should NOT be fired in any Webley revolvers!

Limit revolver velocity of 270-grain bullets to 600 fps and 230 grain ones to 700 fps by using 3.0-3.5 grains of Bullseye or 4.5-5.0 grains of Unique. You can determine safe charges with other powders in “shaved” .45 ACP Webleys or unaltered .455 revolvers using the 0.88” length .455 Colt cases by adhering to the “start” load charges listed for .45 ACP using #452374 in the Lyman Cast Bullet Handbook, 4th Edition (2010) on p.278, which do not exceed 13,000 cup. Reduce these charges by 10% either for heavier bullets or for use in shorter 0.76” Mk II cases, unless you are able to measure velocity of your revolver over a chronograph. Careful charge adjustment may be cautiously used to obtain uniform ballistics within the stated limits to compensate for a very large cylinder gap over 0.010”, which is very common in these revolvers. While you must be careful when reloading for any 100-year-old revolver, the Webley is a utilitarian piece of history which can be enjoyed with appropriate ammunition.

I had a Webley Mark IV Boer War period cylinder and frame Rockwell tested during the course of repair. The cylinder did not register at all on the "C" scale, being 85-87 Rockwell B, which is typical of plain carbon steel similar to 1035 quenched and tempered. The frame was Rb90, its "black powder" metallurgy being remarkably similar to Colt Single Actions produced in the same pre-1900 era.

You must be aware that the chamber throats of Webley service revolvers are highly variable. I encountered a .004” range of diameters among the various chambers of my 1914-era Mk VI. Several chambers were smaller than barrel groove diameter. With soft hollow-based lead bullets using black powder, this allows the bullet to swage down passing through the chamber throat, getting the most energy from a small powder charge, and the hollow base expands up again as the bullet passes through the barrel forcing cone to engage the rifling. But, I repeat my warning that firing hard-cast or jacketed bullets larger than cylinder throat diameter, such as the M1911 .45 ACP service bullet, combined with fast-burning powders such as Bullseye, can spike chamber pressure dangerously and should be avoided!

Webley Gunsmithing Adventures!
As a case in point, I once owned a former Queensland Police Mk IV with bird's head grip and 4" barrel, converted to .45 ACP. I fired about 500 rounds of 230-grain Saeco #954 cowboy bullets, as-cast of wheel weight metal, .455" diameter in Winchester .45 ACP cases and WLP primers with 5 grains of Bullseye. This is a standard but full-charge .45 ACP load producing about 830 fps in an M1911 pistol, 800 fps in my 5-1/2" S&W Hand Ejector and 750 fps in the 4" Mk IV, a Boer War period piece with large cylinder gap. While running the falling plates firing in rapid DA, the barrel catch popped open. This occurred during a match, so I closed the revolver and fired one more shot and the gun popped open again.
Upon further inspection it was determined that the barrel catch screw had sheared off! Disassembling the gun, it was apparent that the barrel catch had spread open slightly so that the snapped off barrel catch screw could be removed by hand, leaving the broken, threaded stub in the frame. The hole in the frame for the barrel catch screw was slightly elongated as a consequence of the failure.

Sandy Garrett of Northern VA Gun Works tore down and inspected the revolver. He admonished me for my “accelerated endurance test " firing the equivalent of proof loads, reminding me that I was no longer “being paid to destroy guns for a living,” and that I, of all people, should know better! Because the shaved revolver gun had no collector value, Sandy made a replacement barrel catch screw of larger diameter than the original.

He used a heat treated 18-8 high carbon steel M4 metric bolt, reaming the hole in the frame on the milling machine to repair the slight elongation produced during the failure. He also polished the barrel forcing cone, uniformed the cylinder throats to .4525 with a Manson reamer and made minor lock work adjustments. I spent as much on repairs as I did originally for the gun, but it now excels in rapid DA work and is "married" to mild loads with the 230-grain Saeco #954 using 3.5 grains of Bullseye, for 630 fps. With luck, and avoiding similar future stupidity, it should last another 115 years.

After it was repaired, I swapped my Mark IV to a friend who appreciated its Queensland history and understood its loading considerations. In exchange I received his 1914 original date of manufacture Mark VI and kit, being arsenal rebuilt for WW2 service in 1940. I used the Mk VI as the test platform for this article to fire charge establishment, working up .455 loads in Hornady and Fiocchi Mk II and in Mk I brass obtained from Reed’s Ammunition and Research to approximate WW2 service load velocities.
My new-to-me Mk VI Webley revolver has also proven to be a satisfying gunsmith’s adventure. While function and accuracy were very good for its type, it was plagued by occasional fliers and leading of its too-tight cylinder throats. After establishing baseline performance, I sent the cylinder off to DougGuy to have the throats uniformed. Thorough cleaning and close examination revealed residual circumferential tool marks from its original manufacture, as well as deep pitting which had hidden for years under accumulated lead and encrusted carbon fouling. DougGuy initially trued the throats to .4525” with an NM95 Borazon stone in the Sunnen hone to remove tight spots and enable close inspection, proceeding to clean up the worst damage in 0.001 increments, photographing the progress in stages. He explained:

“Uneven throats cause differences in pressure which make the gun recoil differently in the hands from shot to shot, and groups open accordingly… It is more important that throats are even than what size they are. You can always size bullets to fit the throats. Pitting makes the throat diameter larger, which will both vent off pressure before the bullet leaves the cylinder, and it will lead the cylinder any place where gas escapes… Honed to .4555" with the 500grit borazon stone, the throats…show a HUGE improvement… I can see a seal down low in the worst throats, and I stopped here because I do not want to polish out the pitting to the point where it is too shallow to hold lube, powder residue…better to leave it where the residue from firing will have a good chance at sealing…

“Here are the .4555" throats, and chambers, all polished up with an 800grit ball hone. A .4555” pin gage goes smoothly and evenly in all the throats, a .456" won't go in any of them. I am quite satisfied with this endeavor, and for sure want to know how well it shoots… At the very worst, if you have 2 chambers that are not shooting to the same point of impact as the others, two things can happen. You could mark them with empty 45 ACP brass that would remain in the chambers, or you could send the cylinder back and see what taking the throats to .4565" does for it. My thoughts for the best scenario are that you fire the gun enough times to fill in the remaining pits, and determine that it shoots pretty good and just roll with it… You should see a tremendous improvement right away. For once, the caliber REALLY IS what the bullets are, and you now truly have a 455 Webley!”
Soft Bullets and Mild Loads Are Best for Old Revolvers

[Larry Gibson]

The .455 bullets are best when soft. I use a mixture of 50/50 plumber’s lead and backstop scrap with 2% tin added, approximating 30:1, about 9 BHN. Harder alloy is not needed, because velocities should not appreciably exceed 700 fps with 230-grain bullets or 600 fps with 265-270-grain ones.
Fiocchi brass uses small pistol primers while Hornady uses large pistol primers. The other alternative is to modify Starline .45 Schofield cases. Ron Reed sells .45 Schofield cases modified to either .455 Webley Mk II (0.76”) or .455 Mk I Eley/Colt (0.88”) for $60 per 100. This is a very fair price considering the machine time needed. Doing so involves thinning the rim from the front from .055 to .039 and shortening the case body. Modified .45 Colt brass can also be used, but its smaller .512” diameter rim versus .520” for the Schofield and .535” for the Webley, may fail to engage with the extractor, which occasionally leaves a fired case or two in the chambers. The larger rim diameter of Starline Schofield brass, while smaller than original .455 cases, is more nearly correct, and is enough smaller in diameter to avoid rim interference which occurs when Hornady or Fiocchi cases are used in adjacent chambers of the .45 ACP Kirst conversion in the Ruger Old Army and Pietta New Model Army Remington type revolvers. The worst case when using modified .45 Colt brass in a Webley is having to manually poke a case or two out of the chamber every once in a while. This is not a problem at the range, because you are not having to clear angry hordes of charging, bayonet wielding Huns from your trench!

Firing .455s in the Ruger Old Army with Kirst .45 ACP conversion installed proved safe, accurate, and reliable. Groups were about half those produced by the Webley in its original condition. It was easy to hit the 12” gong standing two-handed most of the time holding center-of-mass at 100 yards! Cylinder throats of the Kirst cylinder are .4535”, an acceptable fit for as-cast soft bullets from my Accurate molds.

I was curious to see how much velocity gain was measured in the Ruger with 0.004” cylinder gap and 7-1/2” barrel, compared to the Webley Mk VI with its huge 0.018” cylinder cap and 6” barrel. In my first test I established a performance baseline firing 1942 British service ammo by Kynoch. These produced 567 fps in the Webley, 580 fps in the Ruger and 680 fps from my H&R Rook and Rabbit Rifle by John Taylor with 20-inch barrel. Despite a few hang-fires and two misfires, accuracy was acceptable and in all rounds which fired, bullets exited the barrels without mishap. Had I NOT been prepared with lead hammer and Brownell Squibb Rod, the Scheutzen troll could likely have indulged in his mischief!

Next was to test Unique powder hand loads with 4.5 grains of Unique in Hornady brass with the MiHec 265-grain MKI hollow-based bullet. These gave 538 fps in the Webley, 679 fps in the Ruger and 788 fps in the H&R carbine, being a very good approximation of the original lead bullet service ammo.

The Mk VI revolver came with several hundred rounds loaded with #452374 and 5 grains of Unique in the Hornady cases. Being cautious, I felt this starting .45 ACP load might be a bit “warm” in the Webley. So, I shot them first in the Ruger Old Army cartridge conversion and in the H&R Rifle. The Lyman cast hardball-shaped bullet shot to the sights of all three guns, and represents a good “full charge” in Mk II brass load for the Webley. Velocities recorded were 648 fps in the Mk VI (a maximum load not to be exceeded, considering its 0.018” cylinder gap), 716 fps in the Ruger and 814 fps in the 20” H&R.

Velocities measured with 1942 Kynoch FMJ ammunition and cast bullet hand loads using Unique powder agreed with published references as to what they “should” be, considering cylinder gap. The velocity gain in firing Kynoch MkVIz in the Ruger was less than that experienced shooting lubricated lead bullet loads of similar energy. Pooling all five load samples fired in the Webley, their combined average velocity was 578 fps. This reinforces the well-established advice from our experienced Canadian neighbors that when working up loads for these revolvers, you should not appreciably exceed 700 fps with 230-grain bullets and not exceed 600 fps with heavier 250-270 grain one. I agree completely.

Pooling the samples in the Ruger, its average velocity was 667 fps, or 89 fps faster than the Webley. This validates the advice that in working up .455 loads in your S&W .455 Hand Ejector or Colt New Service the 700 fps published velocity for the .455 Colt/Eley is still a good benchmark. BUT, if your sturdy Colt or S&W .455 likes a load exceeding 700 fps, you should NOT use that load in your Webley.

Proper bullet “fit” is essential for safety as well as accuracy. It is common to encounter .455 Webleys having “tight” cylinder throats as small as .450”, whereas Colts and S&Ws often run .457-.459” Those inclined to hand load based only upon what they read, without MEASAURING their revolver, may assemble ammunition with hard, oversized bullets which dangerously spike pressure. Original design soft, hollow-based bullets like the Mk II tolerate being squeezed through tight throats and will slug up again to take the rifling of a larger barrel. But doing so today is NOT the best technical solution.

I recommend that cylinders be measured with gage pins and honed, when necessary, to 0.001” to 0.0015” larger than barrel groove diameter. A modern mold of design optimized for the Webley cartridge should be selected, which produces correct bullets that “fit” when cast in soft 8-10 BHN alloy.
Reaming cylinder throats and having new Accurate molds cut to fit made a big difference in accuracy. A charge of 3.5 grains of Bullseye loaded with soft bullets cast from with Accurate molds 45-240H1 and 45-262H provide a useful approximation of original service velocity, with superior accuracy. While the Mk VI is not a target revolver, it easily meets or exceeds the traditional British service revolver accuracy criteria of One Inch Per Ten [yards], which defines practical handgun accuracy.

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.
Kynoch K42 Mk VIz 265-grain FMJ___537 fps, 29 Sd___________580 fps, 32 Sd________680 fps, 40 Sd
Handloads Assembled in Hornady .455 Mk II cases (0.77”) with Winchester LP primers
#452374 225-gr. LRN 5.0 Unique____648 fps, 24 Sd____________716 fps, 11 Sd_______814 fps, 14 Sd
MiHec 265-gr. Mk I 4.5 Unique______538 fps, 24 Sd___________679 fps, 32 Sd________788 fps, 11 Sd
Accurate 45-259H 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 (0.87”) by Reed’s Custom Ammo
Accurate 45-259H 3.5 Bullseye______546 fps, 16 Sd___________641 fps, 9 Sd_________753 fps, 11 Sd
Column Means By Gun____________Webley 0.018” gap_______Ruger 0.004” gap______20-inch rifle
Pooled Avg. All Samples:___________578 fps________________667 fps______________770 fps
Velocity Gain from Webley__________0____________________+89 fps______________+192 fps

Table -2 .455 Pressure Test Data

Submitted by Larry Gibson, Lake Havasu, AZ
Test Firearm – T/C Contender .45 Colt 10” barrel fitted with piezoelectric transducer to Oehler M43
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 (252 grs., 10 BHN) .452”, OAL 1.29” – 639 fps, 11,400 psi max.*
• Only one shot recorded a high enough pressure to measure on the strain gage
Accurate 45-260H (269 grs., 10 BHN) .452”, OAL 1.30” – 648 fps, 14 Sd, ES 42, 11,800 psi, ES 900 psi
Accurate 45-290H (295 grs., 10 BHN) .452”, OAL 1.298” – 672 fps, 11 Sd, 32 ES, 12,600 psi, ES 1100 psi
Approximated expected velocity drop in 6” barrel revolver est. -100 fps, depending upon cylinder gap.
 
[Separate “sidebar” column] I invited Ric Bowman to comment on my draft, and share his reply here:

Dear Ed,
6 November 2016

Having lived almost 50 years in the Pacific Northwest now, I have some feeling for the shooters out here. Up until Bill Clinton was elected, there was a common gun trade circuit here in NE Washington, the Idaho panhandle and Western Montana. It was Winchester and Marlin lever guns going north and pistols and English guns coming south.
The .45 Auto Rim has always been popular here because it was the cheapest big bore handgun, well-liked by the hippies (i.e. pot growers), gypsy loggers, miners and farmer/ranchers. Probably more of the Brazilian Model 1937 S&W’s ended up here than anywhere in the US. When they dried up and Canada banned handguns, most Canadian handguns came our way. Anybody with a lathe or a drill press could cut the back of the cylinder down to clear AR cases. I’ve seen about every model of Webley and Belgium RIC revolver made in .45 that had a cylinder long enough being reworked for the AR case.

Most of these guys cast their own bullets, either the Lyman #452460, #452423 or one of the Lee moulds. The standard load was a heaping 22 LR case of Bullseye (4.0 grains) and it was good enough. While I did see some Lyman 310 tools, mainly among the shepherds and hippies, farmers and ranchers mostly had old “C” presses and modern dies.

After the Model 1917’s, the best liked were the Webley’s. While I never saw a #1, the #4’s and #5’s were better liked than the #6’s, I think because of the round butt and short barrels. Never saw one blown up, but several with the cylinder bulged with a stuck 45 ACP case in it, mostly military surplus. That and the two chambers next to it were unusable, but it was still usable as a three-shooter. It seemed like every tractor over 50 years old had an AR revolver in the tool box on the fender, uncleaned and full of dust, but they mostly went “bang” when tried.

I have only seen two (2) .455’s that were not rechambered to 45 AR, and I own them both. One is a Webley Mk VI and the other is a S&W Second Model, both were made in 1916 and came over the border from Canada.

Best wishes, Ric

[Rich/WIS]

My copy of COTW lists one-load, a 260 gr bullet with 5.0 grs Unique for 610 fps. Donnelly's conversion manual list one also, 250 gr lead with 3.5 grs Bullseye for 710 fps.

[Outpost75]

My copy of COTW lists one-load, a 260 gr bullet with 5.0 grs Unique for 610 fps. Donnelly's conversion manual list one also, 250 gr lead with 3.5 grs Bullseye for 710 fps.

The COTW data is based on the 0.87" length Dominion .455 Eley case and 5 grains of Unique is excessive in the shorter Starline, Fiocchi and Hornady 0.76" MkII cases. Refer instead to the data in post #4 above.

[Drydock]

If you find a Lee 1st edition "Modern Reloading" with the red cover, it has very useful .455 Webley MK II (Short Case) load data. All the classic Alliant/Hercules powders.

https://www.bing.com/videos/search?q=Webley+Mk+VI+Revolver&&view=detail&mid=745BEE584D863D7E8EAE745BEE584D863D7E8EAE&&FORM=VRDGAR&ru=%2Fvideos%2Fsearch%3Fq%3DWebley%2BMk%2BVI%2BRev olver%26Form%3DVDRSCL%26%3D0

[smkummer]

Lyman 42 published 1960. 258068

[Drydock]

That's MK 1 data, though he does recommend reducing loads one grain for the shorter case.

[Outpost75]

That's MK 1 data, though he does recommend reducing loads one grain for the shorter case.

But also the Lyman data circa 1960 was NOT pressure tested and I would not trust it.

In the #4 post above Larry has pressure tested data firing with modern components which you can rely upon to be safe in the older guns. I use them in my 1914 Webley MkVI and my 1914 Colt New Service .455.

[smkummer]

Yes guys, I wasn’t trying to override all the work that was done here. I simply posted it and it certainly should come with a disclaimer and that being like you said, no pressure testing. My gun is a 1915 colt new service and shoots the 6 grain unique load fine with dominion 455 colt cases. Again, that’s a solid frame gun.

[Outpost75]

Yes guys, I wasn’t trying to override all the work that was done here. I simply posted it and it certainly should come with a disclaimer and that being like you said, no pressure testing. My gun is a 1915 colt new service and shoots the 6 grain unique load fine with dominion 455 colt cases. Again, that’s a solid frame gun.

Even the pre-1917 Colt New Service revolvers which didn't have heat-treated cylinders were stout guns compared to the British top-breaks. Early M1917 .45 ACPs assembled with leftover, faced off .455 cylinders are not as strong as the later guns having purpose-built .45 ACP heat-treated cylinders identifiable by having a stop surface to headspace the case, permitting using loose .45 ACP ammo without clips.

[Dutchman]

https://images52.fotki.com/v1552/photos/4/28344/9895637/w1s-vi.jpg (https://public.fotki.com/dutchman/firearms/w1s.html)

[Dutchman]

https://images46.fotki.com/v1660/photos/4/28344/9895637/w2s-vi.jpg (https://public.fotki.com/dutchman/firearms/w2s.html)

[Dutchman]

https://images45.fotki.com/v1200/photos/4/28344/9895637/w3s-vi.jpg (https://public.fotki.com/dutchman/firearms/w3s.html)

[Dutchman]

https://images12.fotki.com/v1667/photos/4/28344/9895637/w4s-vi.jpg (https://public.fotki.com/dutchman/firearms/w4s.html)

[Dutchman]

https://images51.fotki.com/v731/photos/4/28344/9895637/w5s-vi.jpg (https://public.fotki.com/dutchman/firearms/w5s.html)

[Dutchman]

https://images46.fotki.com/v677/photos/4/28344/9895637/w6s-vi.jpg (https://public.fotki.com/dutchman/firearms/w6s.html)

[Dutchman]

https://images20.fotki.com/v682/photos/4/28344/9895637/w7s-vi.jpg (https://public.fotki.com/dutchman/firearms/w7s.html)

[Bigslug]

3.4 grains of Red Dot was what I settled on for the MKII bullet & that has it going at an average of 612 fps.

3.2 grains of Red Dot was the my final charge for the ~230ish grain MK4. Don't have a recorded speed on that box...