Hello. New to this board and asking for any help on loading cast bullets in a 2nd model S&W .455 that has been converted to .45 Long Colt. My gun is part of the original Brit contract to make over 75,000 revolvers for WW-1.

The serial is # 324XX, has 6.5 inch barrel and in very good condition. Cylinder conversion was done by what looks like a competent smith, has bevel step to cylinder throats.

The cylinder throats are what has me worried about what cast bullet to use in this gun, they are .457 diameter, and the barrel is .453 or .454.

Cannot get an accurat reading with dial calipers but did slug the barrel with lead cast bullet.

Problem...will the overbore of the cylinder throats being .457 cause the firearm to be inaccurate?

Will hollow base bullets help, if so, what weights should I strive for to load.

Thanks for any useful experience from anyone who has reloaded same type of firearm.

A44and45

It isn't an ideal situation, as you surmise, but having the throats larger than the bore is a helluva lot better than the other way round!

If it were mine, I'd size the bullets to .456 or .457" and see what happens. You'll be sticking to loads at the low end of the 45Colt spectrum with this revolver (use data for the Colt SAA early models) so use bullets a bit softer than usual and you'll be fine. If you can meausre tham or order them for hardness, try a BHN of about 10-12 first. That would be with an alloy of about 1-16 or 1-20 tin-lead. I'd even use a soft, blackpowder style lube like SPG with these loads.

Softer bullets will be much kinder on this old warhorse than typical "harder that a mother-in-law's stare" commercial cast bullets. More accurate, too!

Hi Rocky. Sounds like good advice to me, I had planned on keeping the loads in the 650 to 750 fps range...and soft bullets are the order of the day. Can't see any percentage in using any jacketed bullets, but plated might be OK as they require the same loading tables as the cast stuff.

I am casting my net out for some used swaging dies in .454 or .455, but maybe I should take your advice and go for the .457 with maybe a little hollow base drill-out of about 1/8 of an inch. I've got a mini lathe and technique to HB any size cast bullet to whatever depth I choose.

I seen somewhere there are cast bullets available in .457 size, they may have even been HB. Going to check my favorites for it.

Thanks again...anyone else been there done that...

A44and45

I have one of this pistols just like yours. It was a very common conversion, which is too bad really. I started buying Mid Kansas Cast Bullets "cowboy alloy" .454" bullets and they work pretty good for me. (I'm too lazy to cast small bullets, only do .510" and over)
I turth mine shoots pretty darn good (when you consider the setup) no matter what I use. Federal loads (LSWCHP) shot great for some reason.