646 cylinder

[Duke426]

After reading Wolfgang's thread in the 1980-present section regarding problems with extraction in his 646, I have a couple of questions. (I understand Wolfgang appears to have solved his issue by using metal moonclips rather than the plastic type)

Would hard-chroming the cylinder alleviate the issue? Would hard-chrome or a similar Robar/Birdsong teflon finish provide the lubricity needed to help the empties eject more easily, even with the Rimz clips?

Could a cylinder from a model 686 be fitted to the 646? I don't understand the purpose of the Titanium cylinder in an otherwise stainless steel medium framed service revolver, to begin with.

 

[Ignatz]

Here's what I've read about the 646. Mostly on the Brian Enos forum. The original 646PC has more of a tendicy to have sticky cylinders than the later model with the full lug barrel...The cylinder was made of titanium because of its strength. Theres not a lot of metal to work with putting the larger .40 s&w slug in the same size cylinder as the .38. Reaming out a 686 cylinder puts you in uncharted teritory and the cylinder maybe could fail. Theres got to be a reason why s&w did'nt just make a .40 (686).
I just purchaced an older (original) PC model and am just setting up a new Dillon conversion so I can fire mine. I'm well aware of the problems that you are having, but theres plenty of competitors using these pistols with sucess.
I bought the Ranch Products moon clips to try. PM me with your address and I'll mail you 5 to try. Other than these, it would be the expensive ones from tk custom..dave hearth I believe is his name..I use his moonclips in my 7 shot 586 and they are flawless. I just wanted to try something cheaper.
Remember theres more info on these gun on brianenos.com.

 

[TSQUARED]

I have used the Ranch Products steel moonclips in my S&W 646 without any problems. I do not shoot full power loads through my S&W 646 since I basically use it for steel shoots. As an aside these Ranch Products moonclips also fit and function in the S&W 686 in 38 Super. Using the RIMZ plastic moonclips I have experienced some misfires and ejection difficulties.
I am a fan of the Ranch Produts moonclips and also use them in the 6x38 Special, 8x38 Special, 8x38 Super, 6x45ACP and S&W 610 versions. Great products at a very reasonable price.

 

[OKFC05]

After reading Wolfgang's thread in the 1980-present section regarding problems with extraction in his 646, I have a couple of questions. (I understand Wolfgang appears to have solved his issue by using metal moonclips rather than the plastic type)

Would hard-chroming the cylinder alleviate the issue? Would hard-chrome or a similar Robar/Birdsong teflon finish provide the lubricity needed to help the empties eject more easily, even with the Rimz clips?

Could a cylinder from a model 686 be fitted to the 646? I don't understand the purpose of the Titanium cylinder in an otherwise stainless steel medium framed service revolver, to begin with.

The 646 was designed specifically to shoot PF 125 .40 S&W for IDPA (before the rule change)and ICORE. With steel clips, it works perfectly. It is safe to shoot with full-power .40 S&W with the same steel clips, although that was not the main purpose.

IMHO, you screw with the 646 cylinder at your peril; more than one has been ruined. If you want to shoot major power, buy a 625 in .45 ACP. Please don't ruin an increasingly rare gun trying to "improve" it.

 

[Duke426]

Thanks to all for your replies and knowledge.

I don't have a 646 but was curious about the metallurgy of the cylinder and didn't want to hijack Wolfgang's original thread. Just trying to increase my knowledge of all things Smith & Wesson and this forum does a great job of doing that because of folks like y'all!

Ignatz, thanks for your kind offer. As an aside I live a bit west of you over in York. I get over to Birdsboro area occasionally to service Dyers Quarry with Norfolk Southern railroad.

Thanks again!

 

[jframefreak]

Ignatz, what is the Dillon Conversion you mentioned? I have two of these 646's and I love them.

 

[Ignatz]

I just meant that I bought a complete 40S&W setup to go along with my 4 other complete setups. 550b (45acp, 38spl, 32 s&w long and 9mm). I am running all my brass thru a Redding GRX sizing die before I start reloading. Possibly to help with the extraction problem. And I will load closer to the 125-130 power factor.
After years of picking up "FREE" range brass (9mm and 40 s&w) I bought a Glock34 and recently a Mint 646pc so I can shoot with "FREE" brass. Its only Free untill you buy all the stuff that goes with it. The dillon stuff is'nt cheap either! Fun hobby!

 

[jframefreak]

I see, you were talking about your reloading set-up. I'm trying to put together a low-buck reloading set-up currently. I started with a used RCBS outfit I bought from my neighbor. With a few upgrades it should suffice.

 

[WC145]

The 646 was designed specifically to shoot PF 125 .40 S&W for IDPA (before the rule change)and ICORE. With steel clips, it works perfectly. It is safe to shoot with full-power .40 S&W with the same steel clips, although that was not the main purpose.

IMHO, you screw with the 646 cylinder at your peril; more than one has been ruined. If you want to shoot major power, buy a 625 in .45 ACP. Please don't ruin an increasingly rare gun trying to "improve" it.

And if you do ruin one you're SOL, I spoke to S&W the other day and asked if there were any replacement 646 cylinder available and was told no.

 

[jframefreak]

What exactly is the "power factor" you guys are talking about?

 

[WC145]

On the subject of 646 moonclips, I just rec'd the ones I ordered from Midway. They are Ranch Products brand, same as TSQUARED and Ignatz have. They come in packs of 8 for $8.99, I got 3 packs and it was around $35 with postage.

I have yet to shoot with them but on inspection it is obvious that they are much sturdier than the original S&W version, which is made similar to the Taurus "Stellar" clip (it's anything but!). They don't have the split in between where the cases clip in so it takes some force to insert the case and they snap in very securely, much like the 940 moonclips. I'm sure you could drop a loaded one in your pocket and not worry that it's going to come apart. Of course, that means the cases will be a bit difficult to remove so the tool that comes with the gun will be a help.

That's all, just a bit of info for anybody that's interested.

 

[tomcatt51]

What exactly is the "power factor" you guys are talking about?

Bullet weight in grains multiplied by velocity in fps divided by 1,000.
147 gr X 1,250 fps / 1,000 = 183.75 Power Factor (PF)

 

[jframefreak]

Bullet weight in grains multiplied by velocity in fps divided by 1,000.
147 gr X 1,250 fps / 1,000 = 183.75 Power Factor (PF)

I see now, Thank you.