Cylinder Swap: S&W 1917 in S&W HE MkII 2nd Model?

[jmiles1960]

I have a very well worn S&W HE MkII 2nd model revolver in .455 Eley.

Does anyone know if a S&W 1917 (45 ACP) cylinder would work with minimal or no modifications in my HE MkII?

I know many of these were modified to shoot 45 LC. My gun is not matching (cylinder number is different from frame), and virtually no bluing left, so I have no love lost to doing a conversion. It's a cool shooter!

Thanks!

 

[ddixie884]

The best modification is to have it reamed to .45Colt with a countersink cut for the slightly thicker rim. If done right the larger diameter rim of the .455 will still head space on the rear of the cylinder. It will then shoot both the .455 and .45Colt........

 

[cgt4570]

Yes, I've done it. I have a spare 1917 cylinder with my .455.
It isn't a problem, but due to different size frame lugs, the 1917 cylinder will have some forward/aft movement when open.

 

[Oyeboteb]

You might want to check your Groove-to-Groove diameter of the Barrel Bore.

Some of the 2nd Model H-Es in ".455" were .455...some, .456, even .457...

.45 ACP and modern .45 Colt, the Bullets are .452, and would not even touch the Rifling in such Bores.

 

[steelslaver]

You might want to check your Groove-to-Groove diameter of the Barrel Bore.

Some of the 2nd Model H-Es in ".455" were .455...some, .456, even .457...

.45 ACP and modern .45 Colt, the Bullets are .452, and would not even touch the Rifling in such Bores.

Actually 45acp bore diameter is more like .445" and the groove diameter is .452" A 455 probably has a groove diameter of around .448. You would need really worn out rifling to get zero engagement. Slug will get some spin, might lead a bit. Copper jackets would probably not slip much, soft lead bullets might swell a bit from pressure and forcing cone. But, your correct in that it is not the best.

 

[jmiles1960]

Thanks to everyone for the info. If I stumble across a 1917 cylinder, I may give it a try.

 

[steelslaver]

Thanks to everyone for the info. If I stumble across a 1917 cylinder, I may give it a try.

Not hard to find. I might have one in my parts drawer. I am always making 45 into 45 colts.

I just went and looked I have a couple. One is correct vintage complete with the big knob ejector rod. $65 shipped if you want it.

 

[Hondo44]

Thanks to everyone for the info. If I stumble across a 1917 cylinder, I may give it a try.

As ctg4570 posted, with the .45 ACP cyl you'll get a lot of fore and aft slop with cyl open. You can punch out the frame lug in the lower right corner of the cyl window from inside the frame and replace it. Or punch it part way out, turn it 180 degrees, push back in and fit it to the new cyl.

Any pre WWII model Smith chambered for 45 Colt used the same barrel dimensions as the .455 specified as; bore (land) diameter - .447" to .448"; groove diameter - .457" to .458" until the 1950s.

And they didn't ship any that didn't shoot well I've ever heard about in all my years. As you'd expect, .454" bullets work the best.

In the 50's .45 Colt barrels became the same as .45 ACP barrels which were specified as; bore (land) - .445"; groove - .451" from the get go in 1917.

 

[jmiles1960]

Jim (Hondo44) - Thanks for this helpful info. Your wealth of knowledge and experience never ceases to amaze me on all things S&W. Hope to meet you in person one day at SWCA show.

 

[Hondo44]

You're very welcome!

At my age (73) I may not make it to a SWCA show, but it would be great to, and to meet you.