Bore Size on .455?

[Niederlander]

Gentlemen, Does anyone know what the bore size on a .455 Hand Ejector was? Was it larger than the 1917's .451-.452?

 

[glowe]

If you are planning on loading with 45 Colt or 45 ACP lead bullets, you will find them loose in the bore. My 455 S&Ws measure .456" at the throat of the cylinder and .455" groove to groove. Bullets measure .455 according to Barnes Cartridges of the World book.

Groove depths of most revolvers vary from 0.002 to 0.005 inch. So the land to land dimension should be no less than .450" in a .455. Shooting a .452" bullet will barely make contact with the grooves and may not spin properly out of the barrel. Accuracy will almost be guaranteed to suffer with bullets around the same dimension as the lands of a rifled barrel. The 1917 shot 45 ACP which would use a .452" bullet.

 

[Niederlander]

Thanks! Just what I needed to know! (I thought they were oversize for a .451 bullet, but I don't have one to measure any longer.)

 

[P.W.Herman]

I'd use lead .454's . I use them in all my pre war colts.

 

[Hondo44]

From the American Rifleman back when Gen. Julian Hatcher was still on the staff of "Dope Bag":

[Pre war] Smith barrels for 45 Colt chamberings (this does not pertain to post war and current Smith barrels):
He states, "While Smith & Wesson do not ordinarily catalog guns chambered for the .45 Colt cartridge, they have on occasion made them and they list the dimensions, which are exactly the same as they use for their .455 cartridge, as follows: groove diameter--.457 to .458 inch; bore diameter--.447 to .448 inch; 5 lands and grooves, right hand twist; grooves--.144 inch wide, lands--.1368 inch."

 

[Jack Flash]

Hornady makes a 255 grain lead bullet with a .454 diameter. The call it the Cowboy, implying it is for use in Colt .45 revolvers. I haven't bought any recently, but the price per 200 used to be reasonable.
https://www.hornady.com/bullets/handgun/45-cal-454-255-gr-fp-cowboy#!/

 

[bedbugbilly]

The accurate way to find out is to "slug" your bore. Use a soft lead fishing sinker of a just larger than bore size - remove the brass eye and shank and drive the slug through your bore - make sure you oil your bore. Then you can measure with a micrometer to get an accurate measurement of just what you pistol has as far as bore size.

You should also measure your cylinder throats - using pin gauges is the best way. If you throats are smaller than your bore - the throats will determine what size bullet leaves the cylinder to enter the forcing cone and bore.

Normally, if loading cast, going over the bore size by .002 will give you good accuracy - if that size will clear your throats.

 

[glowe]

I have always heard about slugging barrels and it seems not too difficult with rifle barrels, since they can be easily handled and secured, I can't think it is as that easy with a pistol barrel?? I assume you must secure the barrel in a vice, since the chances of bending the frame must be real here. Also, who has all those lead slugs laying around the are "slightly bigger than the bore"? . . . and what is the dimension of slightly? With my luck I would get the slug stuck in the barrel.

Since the chamber throat is available as are both ends of the barrel, a micrometer seems a better approach than beating a lead slug down the muzzle?? Never done the slug approach on a pistol, so don't know how easy it is to drive through the bore?

 

[Niederlander]

I usually use a muzzle loading lead ball a bit larger than the bore. It doesn't take much pressure to drive it down the bore (you can use a wooden dowel), and it makes slugging the bore pretty easy. Yes, it's best to hold the barrel in a vise while you're doing it.

 

[P.W.Herman]

I usually use a muzzle loading lead ball a bit larger than the bore. It doesn't take much pressure to drive it down the bore (you can use a wooden dowel), and it makes slugging the bore pretty easy. Yes, it's best to hold the barrel in a vise while you're doing it.

Yes, easy peasy. I have a variety of sizes of muzzleloading round ball around. Never had and problem holding the gun in hand when pounding a ball through.
This is really the only way you'll be sure you're shooting the right sized bullet. As was mentioned above, cylinder throat size is critical. I have a 1902 Colt New Service in .44-40 that has a .4295 groove to groove size and .427 throats. Haven't been able to get that one to shoot well yet. The .427's just skid down the bore leaving tons of lead.
I suspect if you shoot anything smaller than .454's in your gun you will have the same problem as my .44-40. I'd slug it for sure and let it tell you what it needs.

In my own experiments I find these old guns like soft lead better than hard lead. I try to stay at 20:1 if I can and no more that 700 fps. I think the original loads were quite similar.

 

[Niederlander]

My guess is the only way you'll get that New Service to shoot at all is to open the throats to at least .429. I personally like cylinder throats to be a thousandth over bore size.

 

[P.W.Herman]

My guess is the only way you'll get that New Service to shoot at all is to open the throats to at least .429. I personally like cylinder throats to be a thousandth over bore size.

Yep, my conclusion as well. Imagine, for 116 years this gun hasn't shot well. probably why the bore is in such good shape. I think I'll take it out to .430 so I'll be able to use the same bullets as my S&W 2nd model HE's in .44 special.

 

[Niederlander]

Sounds like a plan. My dream gun would be an early .44 Special Target Model. Don't think that's ever going to happen, though. If I could find a barrel with a fixed sight I would consider building a target model out of a Brazilian 1917.

 

[deadin]

I've never had much luck using the "shim-stock wrap" method of measuring bore diameter of bores with an odd number of grooves.
Throat diameter is OK, but not always completely correct.
(What if the throat is too big and the barrel bore too small??)




(That's what the 265 gr. hollow base Webley bullet is for..)