Smith & Wesson Forum

Go Back   Smith & Wesson Forum > Ammunition-Gunsmithing > Reloading
Forum Register Expert Commentary Members List


Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1  
Old 06-26-2010, 01:25 AM
gaucho1's Avatar
Member
 
Join Date: Apr 2007
Location: Farrrrrrrrrr West
Posts: 1,223
Likes: 639
Liked 324 Times in 171 Posts
Question .455 vs. .45 ACP

How does the pressure compare between these two loads in standard pressure military cartridges?

I recently acquired a 1917 in .455 and I am considering having
the pinnacle type moon clip modification so I can shoot either
rnd.

I was cautioned that the ACP may be too much for the .455
cylinder.
I hope it is appropriate to ask in Reloading as I know you guys
are aware of pressure issues.
Thank You for your help.
John
__________________
I Love This Site
Reply With Quote
  #2  
Old 06-26-2010, 02:01 AM
Member
 
Join Date: Nov 2007
Location: west coast
Posts: 1,487
Likes: 0
Liked 24 Times in 16 Posts
Default

The American .45 ACP was the contemporary of the British .455 cartridge.

One BIG difference, however, is that .445 British started out as a black powder cartridge more than 20 years befor the .45 ACP was developed. Th .45 ACP was started as a smokeless powder cartridge from the beginning. Hence, the .455 British round has the benefit of being developed for use in black powder designs, and evolving into smokeless powder revolvers (Webley MkVI).

Although almost identical in outward appearances and with similar ballistic performance, the chamber pressures are considerably different.

The .45 ACP operating pressures are near what the .455 Britsh proof pressures are. This makes shooting .45 ACP ball ammo in converted .455 revolvers an "iffy" proposition. The S&W cylinders of this period were unheattreated steel.

The contemporary of the M1917 S&W is the British Webley or Enfield (Webley design built at Enfield arsenal) MkVI revolver. Of the many tens of thousands released as surplus after WII, many were converted to fire .45 ACP in half moon clips. Of these conversions, many have developed burst or bulged cylinders from firing the higher pressure rounds.

I have on good authority, heard from Canadian collectors and shooters of the converted .455 that split cylinders are fairly common, as stocks of factory and surplus .455 ammo dried up and shooters had their guns converted to fire the common .45 ACP.

The more prudent shooters (including myself) choose to reload mild 200 grain cast lead bullets to 750-800fps in .45 ACP for use inverted MkVI and M1917 revolvers. You will get no argument from me that the 93-95 year-old revolvers were made when steels and heattreatments were less strong than they are now.

Please be advised that if you go with the .45 ACP conversion, it is not wise to fire .45 ACP ball or high performance handloads. They will certainly chamber and fire, but you will essentially be firing .455 British proof loads with each shot.
Reply With Quote
The Following 2 Users Like Post:
  #3  
Old 06-26-2010, 02:29 AM
gaucho1's Avatar
Member
 
Join Date: Apr 2007
Location: Farrrrrrrrrr West
Posts: 1,223
Likes: 639
Liked 324 Times in 171 Posts
Thumbs up

John
You are always very helpful and have a broad experience and
knowledge base.
As per the Canadians experience, I will either convert and use mild handloads only or will research the reality of reloading
.455.
Any suggestions on sources for loaded .455 or components?

Thank You
__________________
I Love This Site
Reply With Quote
  #4  
Old 06-26-2010, 03:20 AM
Member
 
Join Date: Nov 2007
Location: west coast
Posts: 1,487
Likes: 0
Liked 24 Times in 16 Posts
Default

I've had good results using the factory Winchester or Remngton 255 grain RNF swaged lead bullets. They are 0.456" diameter, intended for use in .45 Colt cartridges, but the diameters are suitable for .455 British. .45 ACP bullets typically are only 0.452". Otherwise you can cast your own or buy from custom cast bullet suppliers.

Fiocci makes loaded ammunition, as does a couple other European makers.

Finding boxer primed .455 British cases should be no problem. Try Hornady, Midway, Starline, and other cowboy action reloading sources.

I would advise NOT converting your revolver, but reload it in the original .455 British caliber.
Reply With Quote
  #5  
Old 06-26-2010, 10:36 AM
Banned
 
Join Date: Aug 2004
Location: South East , PA . USA
Posts: 5,041
Likes: 486
Liked 1,518 Times in 839 Posts
Question

Are we talking .455 Eley or .455 Webley?

I have a Colt New Service in .455 Eley , aka .455 Colt.

The .455 Eley case is longer and uses a heavier bullet that the .455 Webley MkII.

I recently bought several boxes of Dominion brand .455 Eley and .455 Webley at a flea market. Judging from the boxes , the Dominion/Eley stuff is rather old and two boxes of the Fiocchi is fairly recent.
Reply With Quote
  #6  
Old 06-26-2010, 04:33 PM
SWCA Member
 
Join Date: Sep 2003
Location: Ohio
Posts: 291
Likes: 5
Liked 40 Times in 24 Posts
Default

SAAMI pressure for the .45 ACP is 21,000 psi, well above the 14,000-15,000 range for other big bore revolver cartridges of that era like .44 Special and .45 Colt. I'm sure millions of rounds of .45 ACP ammo were fired through Model 1917 S&W's and Colt's during WW I and I've not heard of any problems. Having said that, I only fire low pressure handloads through my guns from that era in deference to their age and lack of heat treatment. I've got plenty of modern N-frames if I want to fire heavy loads. Interestingly, SAAMI pressure for the .45 Auto Rim is only 15,000 psi.

I would definitely not convert your gun from .455 Webley to .45 ACP. I shoot a British-proofed S&W 2nd Model HE that shipped in 1915 and has the officers name engraved on it and would never alter it.

Both Hornady and Fiocchi make ammo, but it's about 80 cents/round. As far as I know only Hornady makes brass and it's only sold through Grafs for $30/100. I bought 200 5 years ago and I've not had a single case split with 10 reloadings. I use the Remington flat point 250 grain lead bullets; they're .456 diameter, which is perfect for this cartridge. I've heard that the Fiocchi brass is very thin and splits easily, but I've never bought their .455 ammo, so I don't know that from experience.

My gun is a pleasure to use and shoots to point of aim at 50 feet. I can shoot just as well at bullseye targets as with a modern .45 revolver (but not as well as my Model 52!). I get a certain satisfaction from shooting guns that have some historical significance as opposed to modern guns.

Have fun!
Reply With Quote
  #7  
Old 06-26-2010, 05:10 PM
gaucho1's Avatar
Member
 
Join Date: Apr 2007
Location: Farrrrrrrrrr West
Posts: 1,223
Likes: 639
Liked 324 Times in 171 Posts
Default

HK
I guess the lower pressure on the .45 Colt is why that conversion does not seem to have the same cautions as the ACP.
Auto rim would not need to cycle a 1911,so it must have been optimized for period revolvers.
I notice a triple lock for sale that has been converted to ACP.
I wonder if the cylinder was bored or changed out.

I just checked and the listing states Auto-Rim.
__________________
I Love This Site

Last edited by gaucho1; 06-26-2010 at 05:43 PM. Reason: New Info.
Reply With Quote
  #8  
Old 06-27-2010, 08:02 AM
Member
 
Join Date: Dec 2009
Location: Indiana
Posts: 1,711
Likes: 285
Liked 564 Times in 325 Posts
Default

I have a .455 that has been converted to .45 acp. I shoot only mild
hand loads with cast bullets in AR brass, no .45 acp jacketed bullet
loads. However, I think that the over size chamber throats of the .455
will serve to keep chamber pressures down reletive to the .45 acp in
revolvers originally made for the acp. This is evident in the lower
velocities seen with the same loads in converted .455 revolvers than
seen in revolvers originally made for .45 acp.
Reply With Quote
  #9  
Old 06-27-2010, 03:31 PM
gaucho1's Avatar
Member
 
Join Date: Apr 2007
Location: Farrrrrrrrrr West
Posts: 1,223
Likes: 639
Liked 324 Times in 171 Posts
Default

alwslate
What diameter bullets are you using?
How is the accuracy?
__________________
I Love This Site
Reply With Quote
  #10  
Old 06-28-2010, 07:53 AM
Member
 
Join Date: Dec 2009
Location: Indiana
Posts: 1,711
Likes: 285
Liked 564 Times in 325 Posts
Default

The handloads that I prefer use 255gr swc's of .452-.453 dia. The light
weight 185-200gr bullets designed for use in the 45 auto impact very
low in the revolvers I own. My bullets are purchased, not cast, hence
the dia. In general I have found that the heavier bullets give better
accuracy than the lighter ones and more consistant velocities. At 50-
60 ft. in my back yard over my bench rest of rolled up rug atop my
air conditioner I can usually see best groups of under 2".
Reply With Quote
  #11  
Old 06-28-2010, 08:36 AM
Jack Flash's Avatar
SWCA Member
 
Join Date: May 2005
Location: Michigan
Posts: 3,567
Likes: 1,973
Liked 502 Times in 307 Posts
Default

Hornady still makes a lead "cowboy" bullet sized to .454 inch, which works well in this caliber. Hornady Manufacturing Company :: Search results

Here's some information / experience I have gleaned over the years with this round. I hope it's not way more than you want!

1960s vintage Lyman Manuals have loading data for both the longer Mk I and the shorter Mk II cartridges.
Old manuals are usually available at gun shows if you look for them.
Also, Pet Loads by Ken Waters has a lot of very useful information and load data on the .455 Eley/Colt/Webley.

By the way, if you are interested in the history of this cartridge "family", Cartridges of the World is a good place to start.

My understanding is that the .455 Eley, the .455 Revolver Mk I, and the .455 Colt are all basically the same cartridge. The case length is 0.880".

Originally a black powder round, ".455 Revolver Mark I" was the British Army's designation for the cartridge when they adopted it in 1892. Perhaps Eley wanted to put their own name on the round for commercial sales to civilians? (Colt always hated to put anybody else's name on their barrels, so they had to “create” a round and name it after themselves ).

When smokeless powder was introduced, the British Army went to the shorter, more efficient Mk II version, with a case length of somewhere around 0.770", depending on the reference you are looking at. Colt continued to make the longer round, using smokeless powder of course, up until around WWII or shortly thereafter.

Buffalo Arms has both cases (you need to go to their website for up-to-date information and prices). The .455 Colt is $38/100 and the .455 Webley Mk II is $25/100. When I bought mine a few years ago, they were made from .45 Colt brass cut down to 0.890" and with the rim properly thinned.


I would advise against buying the Fiocchi rounds if your intention is to save the brass and reload it.

A few years back, I bought some Fiocchi .455 Mk II ammunition and shot it in my New Service. Several of the cases split on their initial firing (ie, factory fresh, not reloaded). On examination, I could see that the case walls are really, really thin.

I only had this case splitting problem with ammo from one box; the rounds from another box did not split. Still, I would never reload this thin-walled Fiocchi brass.

One other oddity - Fiocchi uses small pistol primers for this round. I don't know how much an issue this is, but it seems odd for such a large diameter cartridge to use small primers. In any event, the reloading data I have seen calls for large pistol primers.

“Will the longer MK I cases chamber in S&W's chambered for .455 Webley? “
There is an easy way to find out.

If you don't have a fired .455 Mk I case, get a fired .45 ACP case and insert it to test for chamber length. If it goes in flush with the back of the cylinder, or nearly so, then the .455 Webley Mk I will also fit since its case length is the same.

Of course, just because a round will chamber does not mean it is safe to fire it in that particular revolver. Remember that many British revolvers were made during the black powder era and it is not safe to shoot smokeless rounds in them.

Also, some revolvers were converted to accept .45 ACP when they were imported to the US. These conversions were done to increase sales, often with little or no regard for safety.

It may be wise to do a thorough investigation, including advice from a knowledgeable gunsmith, before shooting one of these old revolvers.

I bought several boxes of loaded Dominion .455 Colt from a local gun shop. They said they got it from another little shop that went out of business. It pays to keep your eyes open.
[Shown below with Fiocchi Mk II for comparison. Note the small pistol primers on the Fiocchi rounds.]

__________________
Splittin’ hairs, aint ya Boss?

Last edited by Jack Flash; 06-28-2010 at 08:44 AM.
Reply With Quote
The Following User Likes This Post:
  #12  
Old 06-28-2010, 09:18 AM
bmcgilvray's Avatar
SWCA Member
 
Join Date: Jan 2006
Location: Texas
Posts: 2,188
Likes: 1,036
Liked 610 Times in 203 Posts
Default

I'd sure leave the gun as is and shoot .455 in it. The .455 is a good round in its own right. I too have good luck with 250-255 grain lead .454 " diameter bullets in a Webley Mark VI that I have.

"I would advise against buying the Fiocchi rounds if your intention is to save the brass and reload it."

This correlates to my experiences with Fiocchi .455 brass. I've obtained a total of 7 boxes over the years and all gives unsatisfactory performance. The cases are thin and also brittle. Several losses may be anticipated in the initial firing of the factory loads and it goes downhill from there if they are handloaded. Very disappointing given the cost of the ammunition.
Reply With Quote
  #13  
Old 06-28-2010, 10:47 AM
Member
 
Join Date: Sep 2002
Location: Tampa, FL
Posts: 63
Likes: 1
Liked 4 Times in 1 Post
Default

I set out to duplicate a .455 Webley load in my Mark V, which had already been converted to .45 ACP when I got it. I start with Auto Rim brass and after trying all kinds of projectiles I've ended up with the Remington brand 255-grain swaged lead bullets already mentioned by poster John Traveler. They fit very nicely. The real key to the deal, though, is the crimp. The problem is that the taper crimp you get from standard .45ACP and .45 Colt dies just won't keep those fat bullets from walking forward out of their cases inside the chambers under recoil. The solution is a Redding .45 roll crimp die, with which you can set exactly how much crimp you need, no more or less. It works like a charm -- big old bullets going about 625 fps, great accuracy, unstressed Webley good to shoot forever.
Reply With Quote
  #14  
Old 07-10-2010, 03:39 PM
Member
 
Join Date: Jan 2008
Posts: 12
Likes: 0
Liked 0 Times in 0 Posts
Default Loading the .455 Webley.

The Colt Eley .455 mark II case is longer than the Mark I case and extends beyond the cylinder stops in a Webley revolver. This therefore is a far better option (the Mark II case) for the Webley because the metal in the base of those cylinder stops is paper thin. The Hornady cases are Mark I's.Lee put out good reloading dies for the .455 Webley and their powder specs should be adhered to and not exceeded. The correct military bullet is thrown from the .455- 265 grain round nose hollow based bullet R.C.B.S. mould.
I would stand by those who caution the use of factory .45 a.c.p. ball ammunition. The Webley isn't strong enough an action.
Reply With Quote
  #15  
Old 11-28-2012, 09:39 AM
Checkman's Avatar
US Veteran
 
Join Date: Nov 2003
Location: Idaho
Posts: 604
Likes: 431
Liked 265 Times in 98 Posts
Default

I own a converted Mk VI (mfd. 1924). For awhile I was shooting very mild reloads (i.e. anemic) with lead SWC bullets. The Webley did just fine, but after a few sessions I decided that the old warhorse should be retired to the pasture. After all I purchased the revolver because I had always wanted one in my collection. It was one of my Holy Grails. I didn't purchase it for real world applications or even for target shooting.

So after having enjoyed shooting it and getting the experience I moved it to my safe. Now I pull it out to show to fellow gun buffs and sometimes just to play............er............admire.

Hey it might not be in .455 anymore, but it's still a Webley Mk VI. It took me years to find one and beggars can't be choosers. I'm content.
__________________
I type. Therefore I am.
Reply With Quote
  #16  
Old 12-03-2012, 10:24 PM
Member
 
Join Date: Jun 2007
Posts: 503
Likes: 423
Liked 24 Times in 15 Posts
Default

I have several converted 455s and handload light 185 - 230 lead loads. Very fun to shoot at close ranges.
__________________
Tommy
Reply With Quote
Reply

Tags
1911, 2nd model, 45acp, bullseye, cartridge, colt, commercial, crimp, engraved, fiocchi, gunsmith, hornady, lock, m1917, military, model 1917, model 52, model 625, projectiles, remington, sig arms, starline, webley, wwii

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
Reloading Thread, .455 vs. .45 ACP in Ammunition-Gunsmithing; How does the pressure compare between these two loads in standard pressure military cartridges? I recently acquired a 1917 in ...
LinkBacks (?)
LinkBack to this Thread: http://smith-wessonforum.com/reloading/143635-455-vs-45-acp.html
Posted By For Type Date
.455 vs. .45 ACP This thread Refback 05-12-2013 10:06 PM

Powered by vBadvanced CMPS v3.2.3
smith-wessonforum.com tested by Norton Internet Security smith-wessonforum.com tested by McAfee Internet Security

All times are GMT -4. The time now is 04:52 PM.


© S-W Forum, LLC 2000-2013
Smith-WessonForum.com is not affiliated with Smith & Wesson Holding Corporation (NASDAQ Global Select: SWHC)