640 no dash that chambers .357 Magnum ??

[John M]

So while tinkering with the toys today, I noticed that one of my Model 640 no dashes in .38 S&W Special, SN BPUXXX, chambers .357 Magnum. What could be up with this? This is not a J magnum frame, and a cartridge loaded with a 158 grain LSWC just barely fits within the frame window (cylinder rotates without binding). Anyone ever see this before, or have a plausible explanation other than DIY gunsmithing by the previous owner?

Thanks,

 

[Andy Taylor]

No explaination other than the gunsmith one. I wouldn't shoot .357 in it. I fact, to be on the safe side, I would look into a new .38 cylinder.

 

[murphydog]

I don't know if a J frame .357 cylinder will fit into a .38 frame, possibly also with shortening the forcing cone? In any case, agree with not using full-power .357 ammo.

 

[mtelkhntr]

Years ago I saw one at a gunsmiths in Western Montana. The guy said he was connected with S&W at one time and they'd sent it to him to work with as they were contemplating offering the 640 in 357. That's been so long ago I don't remember any particulars about the pistol other than I should have bought it when he offered to sell it to me. Like the others, without it being marked 357, I wouldn't go down that path for all the love nor money in Kentucky.

 

[John M]

Thanks. Gun shows no signs of abuse or overpressure and shoots well, so I'm not inclined to try to replace the cylinder, but I'll have to make sure to keep my .357 loads from getting mixed in with ammo for this gun.