Hello all, new to your forum but not new to reloading.
I am reloading Webley 455 for milsurp shooting and looking for discussion and or advice.
Currently using Bertram brass cut down to Mk2 length, Winchester large pistol primers and Bullseye. Casting with an RCBS 265 hollow base mould using 40:1 lead/tin. Loading on Dillon 550 with Lee dies.
My pistol is a MkVI WS Target with 7.5 inch barrel.
Here is the rub, it shoots straight but leaves unburnt propellant in the chambers. Do you reckon I need to crimp tighter to raise pressure or maybe a different powder?
I donât have a chrono so I donât have a clue how slow I am lobbing the pumpkins but put it this way⌠If I donât like my shot, I can just about run down range and catch them before they hit paper 
Firstly welcome mate.
How deep is the hollow in the base? Would a tighter crimp risk deforming the pill?
Have you tried loading with trailboss, its my favourite way to go slow.
Iâll be following this closely as a Webley is definitely on my list.
Thanks for your kind greeting,
5mm deep.
As i understand it, the gas pressure flares the rim of the base as the bullet goes through the forcing cone which enables its engagement with the rifling so Iâm not worried too much about the deformation at loading.
The original Kynoch rounds I have collected all seem to have a pretty robust crimp.
I donât have Trailboss (yet) but have plenty of BE on hand and it is the only powder listed in the old Lyman reloading book that is still on the market here in Jacindastan!
On investigation Bullseye is Trailboss, or at least the equivalent. So yeah, maybe a tighter crimp is the go.
After that iâd try stepping up the load maybe. I donât how much your using, Iâve mostly loaded milsurp rifles with TB and would start at 3/4 case volume (with projectile seated) and creep it up from there. Keeping in mind you NEVER want to compress it.
Is Jacindastan occasionally refered to as New Zealand?
Yes mate, the evil witch whose government single handedly rooted our sport over here in the only country left that runs a fully government endorsed apartheid system.
I am running 3.4 grains of BE which should yield over 700fps (I call BS on that btw) No worries about compression, itâs a fraction of the case volume!
I hear you mate. She will go down in history as Un Zudâs Jonny Coward.
Well I definitely think you should up your crimp and your powder charge mate.
Thanks mate, I will go for .2 and a little more roll then report back 
Youâll probably find that thereâs a bit of erosion half way through the cylinder chambers, due to older black powder ammo. So my suggestion is to work the crimp rather than charge volume. Thatâs what I do.
Iâd try to borrow a chrono to be safe, you should be playing within 650fps max velocity. Personally, I go for 515 (just looked up my load data), but I use a different powder.
Also, you could consider a grease cookie to build up volume density, maybe, sort of like you would with Martini Henry loads (few videos on that).
Also, welcome! 
Sheâs a 1916 MkVI mate, itâs extremely unlikely she ever saw BP loads. Thanks for the tips, I will look into it.
Not just black powder, but corrosive primers too.
All the .455 loads Iâve found have been very weak compared to the Fiocchi factory ammo (which I know is hot) - I suspect a lot of it is due to Americans concerned about someone loading for black powder Webleys.
Personally Iâve never managed to loads using off-the-shelf 250/255gr projectiles to work properly, but Iâve found a 230gr .45LC/ACP LRN projectile will function pretty well for Metallic Silhouette matches.
The best results Iâve had to date involve 4.5gr of Unique behind a 230gr .452 LRN projectile; I havenât put them over a chrono but they âfeltâ right recoil-wise; they had enough power to knock 200m Rams over, and there no pressure signs on the primers and almost no unburnt powder either.
I had similar results using 4.7gr of Unique and figured that with no appreciable difference in accuracy, I might as well conserve the .2gr of powder per load instead (given how thereâs none available to buy anymore and may not be for years).
One other thing to note: Get the calipers out and measure the front of your cylinder mouths; I think youâll find theyâre generally .450-.451 diameter (and may be slightly different, even on the same gun!). Thatâs normal; the idea was the hollowbase bullet would squeeze through the marginally smaller cylinder front then expand into the barrel. It seems to have worked, but makes âproperâ reloading a pain in the neck.
Well, mixed results. The increased crimp did (I think) improve the burn but in conjunction with the bump to 3.6 gr resulted in a group reminiscent of a âmad womanâs shitâ.
I will next try the new crimp with the 3.4 charge and already, I am suspecting I will get a better resultâŚ
Oh, also I noticed some pressure signs on the primers with 3.6 and (you wonât believe this) a split case!!! I kid you not, from the mouth down about a third of the wall.
Which brass are you using? If youâre splitting cases in a .455 somethingâs not right.
Looking a bit better.
Banged off 30 or so 3.4gr loads with the stronger crimp and at 7 yards off hand, the 5 shot groups were about 6cm.
Still a little unburnt powder left in the chambers but deffo a lot better.
Competed in a Webley shoot over the weekend (came fourth btw) at 7 yards. Here is another Bertram case that has given up the ghost⌠The cases are razor thin at the mouth, much thinner than your standard 45acp case. Not sure what is happening but itâs about one case in 50 at the moment that is failing in this way⌠Thoughts?
I donât load for pistols but first questions I would be asking is how old are the cases and what is their previous loading history?
I suspect they may fail like this if theyâve been over worked & over pressured for too many loads, even if your current load is reasonable. Some of the other blokes will have more specific experience.
The cases were bought new about 14 years ago and have seen up to two reloads.
Thatâs really interesting - might be worth contacting Bertram about it?
I almost exclusively use Fiocchi cases and havenât had any trouble with them, even after multiple loadings.
On a slightly different note: Iâd love some info on your clubâs Webley Match - can you share some details (happy to take them via DM if youâd prefer)?