Excerpt from article below:
A neat little grip that one could put on their 640 (or other J-frame) is a set of Crimson Trace Laser Grips. These are simply a set of grips with a built-in laser. While not as evil as mounting the laser on the head of a shark, mounting the laser in the grip makes more sense for concealed carry work. First, it's a lot easier to conceal; second, you can use your regular J-frame holster for it. On a small handgun like the 640, a laser sight will make it easier to get it on the target, especially in low light situations. I'm not really a fan of lasers, but I feel that they are ideal in these cases, especially the Crimson Trace package.
The Crimson Trace LG-405 fits small round butt J-Framed revolvers like the S&W 640. This laser sight also fits the following revolvers: Airlite, Airweight, Bodyguard, Chiefs Special, Centennial, Ladysmith, models 36, 37, 38, 49, 60, 63, 317, 331, 332, 337, 340, 342, 351, 360, 442, 637, 638, 640, 642, 649, 651 and 940 with round-butt J-Frame
COMPACT LASERGRIPS FOR J-FRAME REVOLVERS
The LG-405 LaserGrips are our latest edition for the prolific Smith & Wesson line of J-Frame Revolvers (Round Butt). They are our most comfortable revolver LaserGrips to date, and feature a recoil reduction pocket to improve control of the smaller Smith & Wesson frame.
Inside the Gun Locker: Smith & Wesson 640
Some people have told me that they don't like small guns because they are too weak; they are not powerful enough for real self defense in the face of a real threat. This is not true, and as evidence, I give you this month's review. This is the S&W model 640. It is a small gun chambered for the .357 Magnum.
If you remember my recent review of the Ruger SP-101, this little revolver is much the same. It holds five magnum rounds, fixed sights, stainless, double action only, short barrel... so what is different? Well, the 640 is a true double action only and sports a hidden hammer. This is something that used to be a custom modification, but is now a common feature.
Let me take you back in time for a bit. Small revolvers have always been the weapon of choice for under cover law enforcement, detectives, private eyes, body guards, or anyone looking for a potent weapon that they can keep hidden. Back in the day, small revolvers only came in small calibers. So, to keep the power levels up, people would just lop off the barrels of their full sized handguns. This gave the shootist a potent package, but it was still bulky and inaccurate, thanks to the loss of the front sight post. Thankfully, those days are long gone. S&W has given the shootist a small framed revolver that sported only five shots, instead of the traditional six. The loss of one round drastically reduced the diameter of the cylinder and the bulk of the weapon. When S&W rolled out the "J-frame" family of revolvers, this was generally cheered as a good thing and people were quite happy with it for some time. Then some people found that they would occasionally have a problem with the hammer catching on things and slowing down the draw. One popular fix for this was the addition of a custom hammer shroud. The Waller shroud is a good example. S&W also released an item often called the lemon squeezer, which was a small hammerless revolver that the shooter cocked by squeezing a lever on the back strap of the grip frame. This proved to be less popular and was dropped (not soon enough) from the company catalog. There are a few still around and you can find them from time to time in pawn shops and gun shows. The most successful little J-frame was called the "Chief's Special." Colt made a similar pistol called the "Dick's Special." Both were chambered for the .38 Special. These guns remained popular for decades and were eventually chambered for the .357 Magnum round, once that became available.
I guess, one day in 1955, someone at S&W was looking at his Chief's Special, with his hammer shroud and said, "Hey, why don't we just make a hammerless version?" So they rolled them out, calling them the Centennial model. (Of course early versions sported the lemon squeezer because you can never get enough of a bad idea.) Once they lost the cocking lever, they became quite popular and S&W has pretty much been making them ever since. The current version in .357 is called the 640. That about brings you up to date if you ignore the large gaps of time and details and skips in models and such.
This 640 came from the factory sporting some nice rubber grips with molded in checkering. They do a fair job of helping make the recoil just less than painful. All testing was done using full power .357 Magnum loads, but if one wished, one could load much milder .38 Special loads to practice with. After an extended shooting session, my firing hand felt numb and abused. It wanted to run off into a corner and whimper.
Only H.P. Lovecraft would be able to describe the trigger (the way it came to me) well enough to do it justice. It feels exactly the same way that a good target trigger doesn't. It is quite horrid. It's almost a two stage trigger, kind of like the draw on a compound bow. The first half is long and heavy, and then the weight suddenly drops with a light, second stage pull that you are unprepared for, so you sloppily stumble through the rest of pull to the trigger break. Have you ever helped someone move a piano down a flight of stairs, and had the other guy suddenly drop it? Yeah, kinda like that. A trigger only Cthulhu would love. The trigger hampered accurate shooting, and I suspect that a nice trigger job will help matters a great deal. I've fired other snubs like this one that had better triggers, with no problem putting the rounds where I wanted them. It might be unfair to judge the 640 because of its bad trigger... but I will. S&W had a long history of putting out guns with excellent triggers. But lately the triggers seem to be so screwed up that they could only be the product of Congress and not that of S&W. Come on guys... pull it together. Well actually, this is not far from the truth. These new bad triggers are often called "Lawyer Triggers" because of all the anti-gun legislation and lawsuits. A lot of companies are afraid of putting out handguns with light, crisp triggers the way that God intended them to be. Fact: Bad triggers are evil.
As I said before, this bad trigger can be resolved with a little ministration from a skilled gunsmith, so I'll move on. The front sight is the traditional ramp style and the rear sight is actually just a groove carved into the top strap of the frame. Very simple, and it works just fine for personal defense work. You are not going to want to try your hand at bull's-eye shooting with this sort of handgun anyway, so this isn't a concern. Regardless, it is still possible to keep all your shots on the target. Even if your target is a soda pop bottle. A knife wielding thug would be an easier target.
Should I decide to take this 640 to a gunsmith and have him slick up the trigger, I am pretty sure this revolver would prove to be just as accurate as the SP-101 that I fell in love with. I might just have to do that. Another thing that might be cool for this 640 would be to get the finish bead blasted. Bead blasting would change the shiny stainless to a flat dull gray stainless that would work better in low light. I found that at night, light reflecting from different light sources makes the gun harder to aim, at least for me... Your mileage may vary.
I've been packing this 640 for a couple of weeks now, and it carries very well. It's small enough and light enough to carry comfortably. Yet this convenient package still gives you enough grip to fill your hand and enough heft to give you confidence. I like carrying a revolver. One reason is that the grips can be smaller, more ergonomic and easier to conceal than an automatic. When you make an automatic handgun, you are limited and you have to make concessions for the ammunition magazine held within the grips. Since a revolver holds it's ammo in the cylinder, makers are free from these constraints. And it's kind of Old School Retro Cool to carry a "wheel gun" around instead of an automatic like everyone else.
Speaking of everyone else, a lot of guys like to customize their handguns, make it more unique and make it their own, by getting some custom grips. Since the "Round Butt J-Frame" has been around for so long, the grip options are virtually endless. Most companies that make grips make them that will fit your J-frame.
A neat little grip that one could put on their 640 (or other J-frame) is a set of Crimson Trace Laser Grips (not reviewed at this time). These are simply a set of grips with a built-in laser. While not as evil as mounting the laser on the head of a shark, mounting the laser in the grip makes more sense for concealed carry work. First, it's a lot easier to conceal; second, you can use your regular J-frame holster for it. On a small handgun like the 640, a laser sight will make it easier to get it on the target, especially in low light situations. I'm not really a fan of lasers, but I feel that they are ideal in these cases, especially the Crimson Trace package.
A neat way to carry spare ammo for your small revolver is to get a couple Bianchi Speed Strips. These are simple, plastic clips that hold the rounds like the teeth on a comb. This is especially nice for concealed carry work because the profile of the held rounds are nice and flat, so they fit well into a pocket. Very handy. They're not as fast to reload from as a speed loader, but with speed strips, you can actually have your spare ammo. on your person very easily.
My wife asked me, "What kinda person would like this sort of gun?" My answer came just off the cuff, "Anyone who likes Pre-1974 Mustangs, Classic Rock and Boiler-Makers." I don't know if that has any meaning or bearing on anything. That's just my thought. It seems to me that a person with a strong sense of personal identity would pack one of these with no problem and no second thoughts. Five rounds of .357 magnum can make a very good argument in any debate. Being able to comfortably and easily carry those five rounds in a concealable package is a good thing. And making that package one that can be brought out quickly to deliver those five arguments so readily, is just about ideal.
I've fired several different loads through the 640, and the one load that seemed to give me the best accuracy and the best balance of power to felt recoil is the CCI Blazer 158 JHP grain load. (For new shooters, JHP stands for Jacketed Hollow Point.) Many shooters scoff at the Blazer ammo because of its low price and the non-reloadable aluminum cases, but it is quality ammo. and I like it. One time I was out with a group of dedicated shooters and we had a chronograph set up. We tested a lot of different loads, in a lot of different calibers, in a lot of different guns. In each caliber, the Blazer ammunition was the most consistent, with the least fluctuation of velocity from shot to shot. Consistency is a highly desirable quality in ammunition. More so than being able to reload the case so you can try again. They got it right the first time. The question of what ammo would be best out of such and such a gun is often debated in gun shops and on discussion forums. Everyone has their own opinion.
My answer: The best load for your particular gun is the load that works the best in your particular gun. While some would suggest to me to use another load, I've found that this load is the one that works the best and I am able to work the best with it. Other loads seemed either less accurate or had a sharper/harsher recoil. Unlike an automatic pistol, with revolvers you can pretty much skip the whole "test for reliability" thing. Very few rounds have reliability problems in revolvers. Those that do are mostly hand loads that are either too hot or are not sufficiently crimped. These are hardly a concern these days with our modern factory loaded ammunition.