James,
The recent Webley letters are particularly interesting to me since I own a 92 year old Mk 6 Webley converted to .45 ACP. I reload for most of my 34 guns. 49 years of reloading with never even a blown primer, and only 2 duds (no powder) in 49 years with thousands upon thousands of reloads, makes me feel somewhat qualified to write this. castboolits.com is a lead bullet reloading and casting site to which I belong. Common knowledge there is that Webleys, even Mk. 6s are not suitable for even factory .45 ACP factory load pressures. One of the top Gurus recently told me that shooting factory .45 ACP loads in a converted Webley is like proofing it each time you fire it, and will eventually shake it loose. He recommended 5.2 grains of Unique behind a 250 gr. lead SWC as his top load. After that, I pulled all my 5.5 gr. Unique loads, and even went lower to 5 gr. Unique/250 gr./.452 lead. All warnings to this load data apply here. Naturally you will find some hot shot who loads his Webley to maximum .45 ACP+P+ pressures and gets away with it. These revolvers are old, and the steels, and heat treatments are not what we have now. To compound the chamber pressure problem, many Webleys, mine included, have .449 chamber throats. I bought a chamber throat reamer from Brownell’s, and reamed them out to .452. This lowered pressure and also increased the accuracy, allowing me to recently outshoot my ‘ol buddy from Texas with his new Kimber .45. The look on his face was priceless. Ha!
For those who buy the old pre-1899 revolvers let me add a word of caution. These old sisters are 111 plus years old with many having rust and timing problems. They were mostly [designed] for black powder pressures. If you must shoot them, do it with only lead bullets, over recommended starting [velocity] loads in a reliable reloading manual, all this after a qualified gunsmith looks it over. I have my Grandfather’s 125 year old S&W top-break in .38 S&W caliber. It’s in very good condition, yet I will only shoot low power starting load powder charges in it. I have shot factory loads in it ages ago when I was a teenager, but no more, only my low power reloads. If you want power, get a new .44 Magnum. or better yet, a .500 S&W. Reloading is a very exacting hobby, and not for the careless, or accident prone. The thought of shooting some of the old cheaper brand pre-1899 revolvers such as H&R, Iver Johnson, Sears Roebuck types, with fresh factory ammo is scary to say the least. If one is not Born Again, don’t even consider it. At best, you could only lose a finger, or two. Better safe than sorry, applies here. If your gunsmith shakes his head and hands it back to you, rest assured it makes a great shadow box addition to any den. Keep buying ammo and canned goods. Read your Bible! Mack