Dimensions on S&W .455

[Jtarm]

I’m eyeballing a semi-local revolver (I’ve seen pictures.) It appears to be a Hand Ejector 2nd Model originally built for the Brits chambered for the .455 MK II. It has the correct British markings.

It has been rechambered to .45 Colt.

Before making the drive to check it out, I’m wondering what I might expect to find so far as groove and throat diameter.

What I’ve read about the .455 cartridge indicates a bullet diameter of .455, which makes me suspect dimensions would be on the generous side.

Since this would be strictly a shooter, I’m not interested if there’s little chance of it being accurate.

[Piedmont]

Probably larger throats and I'm not sure about the barrel but even if normal for .455 that is well within normal for .45 Colts and lots of folks have long loaded .454 or larger bullets in .45 Colts for many years. The larger dimensions wouldn't dissuade me. What I'm saying is there is no reason it should be inaccurate if you just tailor your ammo for it. Regular Winchester and Remington 250-255 conical .45 Colt factory loads were around .454-.455 with a slightly cupped or hollow base. They would swage down or bump up and worked well across a broad spectrum of guns.

[DougGuy]

I have rescued a few Webley cylinders that ended up in the .455" - .456" range and they work well with boolits that fill the throats. My own Uberti (avatar pic) Old West model has .4565" throats and a .451" groove, I shoot 454190 sized .456" over 9.0gr Herco and it's a hoot to shoot, quite accurate at shorter distances, haven't tried it at 50 yards but I suspect it would be acceptable.

[SOFMatchstaff]

I have the identical 6", HE 2nd in 45 Colt, originally 455 Eley proofs an all.

cylinder throats are .457(pin gauge)
bore is .447(pin gauge)
groove is .453 five lands and grooves

It shoots a 225 gr, TC .452 acp style bullet better than I can hold most of the time. I size the case with the older lyman two diameter die and a conservative dose of red dot.

[Jtarm]

I have the identical 6", HE 2nd in 45 Colt, originally 455 Eley proofs an all.

cylinder throats are .457(pin gauge)
bore is .447(pin gauge)
groove is .453 five lands and grooves

It shoots a 225 gr, TC .452 acp style bullet better than I can hold most of the time. I size the case with the older lyman two diameter die and a conservative dose of red dot.

Thanks.

I’ve got a MP 250-grain HBWC I bought for my 25-2, but it’s just too dang long for the .45 AR brass.

[StrawHat]

I have a New Century 455 that was converted to 45 long Colt.

301639

I have not shot it yet.

Kevin