Smokeless Loads in Mark 1 Webley .455 cal

otis

otis

Member
Rating - 100%
12   0   0
Location
Manitoba Interlake Region
I own a Mark 1 Webley .455 cal. in very good original condition. It does not appear to have been upgraded to Mark 2 status, as I understand many were.
I am an experienced reloader and have loaded ammo for the later marks with very good results with powders such as Bullseye, Unique, etc. In the case of my Mark 1 however, I must assume that it was never converted to use cordite and I want to stick to original black powder pressure or less.
Does anyone have some data on using 2400 or Trailboss? I can't seem to find anything online with these powders for .455. I plan to use a 246 grain cast bullet, and at present will use old dominion brass. Thanks
 
MkIs were not converted to MkII.
The service cordite .455" cartridges were approved for all .455 Webleys.
 
MarkIs were upgraded to MKI* by adding a seperate recoil shield, rounding the grip, and reduceing the size of the thumb piece.
Mark II was new production eliminateing the prawl on the grip and made with seperate recoil shield.
Sources
"Webley Story" Dowell
"Webley Revolvers" Bruce & Reinhart
"List of Changes in British War Material"
 
There's still some confusion around with .455 MKI and .455 MKII cases. The MKI and MKII refers to the ammunition in this case, not the revolvers.

The Domionion .455 Colt Eley (aka MKI .455 Webley) has more powder capacity than the MKII case (currently manufactured by Hornady) and can take larger powder charges.

Dominion .455 Colt Eley (aka MKI .455 webley) brass: 5.0 gr Unique with a 255 gr lyman 454190 sized to produces 725 fps at 10,500 psi in a 4" bbl.

Hornady MKII .455 webley brass: 4.2 gr Unique with the lyman 454190 seated with one lube groove outside the case mouth produces 650 fps at 12,000 psi in a 4" bbl. This case is prone to pressure spikes with Unique powder. Be careful with seating depths and flat base bullets - hollow base bullets effectively increase case capacity and are less susceptible to pressure spikes for that reason.

Velocity is measured in my own MKI and MKII revolvers and a chrony and pressures are estimates from Quickload software. Quickload tends to overestimate pressure in the smaller capacity cartridges, probably as a built in safety margin.

Hope this helps.
 
Last edited:
Hey thanks for the info guys. Now has anyone any experience with 2400? There is an interesting article early on in this column pointing out how 2400 will actually produce higher velocity with lower peak pressure than black powder, especially in revolver cartridges. Has anyone tried it in the .455?
 
Been trying Tailboss in a 455 Webley, but haven't done enough testing.

Worked up to 3.6 grains using Hornady Cowboy 255 gr but the chrony failed so I don't know the speed. Supposed to be able to use 4.0 gr easy.

Also use Trailboss in 44 special and it works great.
 
otis said:
Hey thanks for the info guys. Now has anyone any experience with 2400? There is an interesting article early on in this column pointing out how 2400 will actually produce higher velocity with lower peak pressure than black powder, especially in revolver cartridges. Has anyone tried it in the .455?
Click to expand...

I didn't like 2400 in the .455 cartridge. It is dirty and leaves an incredible amount of carbon and unburned powder residue because it is too slow for these smaller low pressure cartridges. It works better in .45 colt or larger size cazrtridges, at slightly higher pressures, and in barrel lengths 6" or longer.

The theory that you are referring to is that 2400 burning curve is approximately the equivalent of BP. The original author of this (not on CGN forum) was discussing the use of 2400 in the context of BP rifle cartridges and he is correct in that context - which is ffg BP in rifle cartridges. Some of the people who read and spread that information on this and other forums assumed it was valid for ALL black powder cartridges without considering that most of these smaller cartridges were historically loaded with faster burning fffg BP back in the day, not ffg. Here is some Quickload data:

Dominion .455 Colt Eley brass, 10.5 gr 2400, 255 gr lyman 454190 seated 0.2", 4" barrel
est velocity: 720 fps
est pressure: 12,000 psi
estimated powder burned: 49% (this is where the incredible amount of powder residue comes from)

You can see from the data that 2400 will work but it does not meet the claim of higher velocity at lower pressure in these smallish pistol cartridges. It is still completely possible to overload 2400 in the .455 and produce over pressure situations, and the efficiency is god awful because it's just too slow for these smaller cartridges. Though it does make amazing fireballs if you shoot it at night.
 
Last edited:
What you say makes sense Jet Hunter. I have some experience with 2400 using it in the 44 mag. Works great there, but haven't used it in smaller cases. Think I'll start with Unique as was suggested earlier for the .455.
I just dug out an old box of Dominion empties and it does indeed say that it is correct for all marks of 455 webleys.
Hey Drillbit. Let me know how you make out using Trailboss. I will leave this thread up for some time, and maybe hear from you again.
 
jethunter said:
I didn't like 2400 in the .455 cartridge. It is dirty and leaves an incredible amount of carbon and unburned powder residue because it is too slow for these smaller low pressure cartridges. It works better in .45 colt or larger size cazrtridges, at slightly higher pressures, and in barrel lengths 6" or longer.

The theory that you are referring to is that 2400 burning curve is approximately the equivalent of BP. The original author of this (not on CGN forum) was discussing the use of 2400 in the context of BP rifle cartridges and he is correct in that context - which is ffg BP in rifle cartridges. Some of the people who read and spread that information on this and other forums assumed it was valid for ALL black powder cartridges without considering that most of these smaller cartridges were historically loaded with faster burning fffg BP back in the day, not ffg. Here is some Quickload data:

Dominion .455 Colt Eley brass, 10.5 gr 2400, 255 gr lyman 454190 seated 0.2", 4" barrel
est velocity: 720 fps
est pressure: 12,000 psi
estimated powder burned: 49% (this is where the incredible amount of powder residue comes from)

You can see from the data that 2400 will work but it does not meet the claim of higher velocity at lower pressure in these smallish pistol cartridges. It is still completely possible to overload 2400 in the .455 and produce over pressure situations, and the efficiency is god awful because it's just too slow for these smaller cartridges. Though it does make amazing fireballs if you shoot it at night.
Click to expand...

I genuinely appreciate this post !....:)
 
jethunter said:
I didn't like 2400 in the .455 cartridge. It is dirty and leaves an incredible amount of carbon and unburned powder residue because it is too slow for these smaller low pressure cartridges. It works better in .45 colt or larger size cazrtridges, at slightly higher pressures, and in barrel lengths 6" or longer.

The theory that you are referring to is that 2400 burning curve is approximately the equivalent of BP. The original author of this (not on CGN forum) was discussing the use of 2400 in the context of BP rifle cartridges and he is correct in that context - which is ffg BP in rifle cartridges. Some of the people who read and spread that information on this and other forums assumed it was valid for ALL black powder cartridges without considering that most of these smaller cartridges were historically loaded with faster burning fffg BP back in the day, not ffg. Here is some Quickload data:

Dominion .455 Colt Eley brass, 10.5 gr 2400, 255 gr lyman 454190 seated 0.2", 4" barrel
est velocity: 720 fps
est pressure: 12,000 psi
estimated powder burned: 49% (this is where the incredible amount of powder residue comes from)

You can see from the data that 2400 will work but it does not meet the claim of higher velocity at lower pressure in these smallish pistol cartridges. It is still completely possible to overload 2400 in the .455 and produce over pressure situations, and the efficiency is god awful because it's just too slow for these smaller cartridges. Though it does make amazing fireballs if you shoot it at night.
Click to expand...

2400 is better in longer cases like you said the 45 colt.
i use it in the 45 schofield and 44 sp with good results.
It jusrt dont work good in 455 short cases.
I use 5 grs of unique in most of my 455 loads same for 450 or 4.5 grs of Trail boss.
Some might think thats hi but i never seen any signs of hi presure.
primers always look good. cases eject easy.
This is a load that alot in the USA use in antique webleys 5 grs of unique. i dont use them big pointed RNHB bullets anymore just .454 or .452 Keith type SWC weight 250 Gr depending on bore and chamber throat measurments.
You know your loads are getting hot when cases become harder to eject and primers flow.
 
One other thing about 2400 in the .455 cartridge was that it couldn't touch the accuracy I got from Unique. For some reason known only to the Brits these old revolvers often have tighter cylinder throats than the bore diameter. A faster burning powder like Unique works better to obturate the base of the bullet to fill the bore after they leave the cylinder. Even with Unique I find accuracy goes wonky if I start loading too light.
 
Last edited:
FWIW I just started working up some loads for my converted Mk 1 using 45acp cases and Hornady cowboy 255 gr rnfp over 3.8 gr. of Bullseye, c.o.a.l. 1.235. Chronograph says avg 450 fps. At 25 meters grouping is good elevation wise and 6" left (probably shooter error)

Anybody got any thoughts or comments?
 
jethunter said:
One other thing about 2400 in the .455 cartridge was that it couldn't touch the accuracy I got from Unique. For some reason known only to the Brits these old revolvers often have tighter cylinder throats than the bore diameter. A faster burning powder like Unique works better to obturate the base of the bullet to fill the bore after they leave the cylinder. Even with Unique I find accuracy goes wonky if I start loading too light.
Click to expand...

Your posts are definitely appreciated!
 
jethunter said:
One other thing about 2400 in the .455 cartridge was that it couldn't touch the accuracy I got from Unique. For some reason known only to the Brits these old revolvers often have tighter cylinder throats than the bore diameter. A faster burning powder like Unique works better to obturate the base of the bullet to fill the bore after they leave the cylinder. Even with Unique I find accuracy goes wonky if I start loading too light.
Click to expand...

Again ;) , I love that word !....:D
 
coldestcanuck said:
FWIW I just started working up some loads for my converted Mk 1 using 45acp cases and Hornady cowboy 255 gr rnfp over 3.8 gr. of Bullseye, c.o.a.l. 1.235. Chronograph says avg 450 fps. At 25 meters grouping is good elevation wise and 6" left (probably shooter error)

Anybody got any thoughts or comments?
Click to expand...

I prefer Unique because it fills the case slightly better but a buddy of mine swears by Bullseye in his .455 MKII.
 
You must log in or register to reply here.
Back
Top Bottom