MAG-NA-PORT’S Custom S&W 640 Magnum

Background

First, as many GunsAmerica readers may know, I am a self-avowed, unapologetic, fan of the Smith J frame series of revolvers. I have carried a J frame, of one model or another, on a daily basis for more than forty years. They weren’t just carried. I put a lot of rounds down range over the years during agency qualifications and personal training. Over the years, I have also come to have an appreciation for custom pistols and the gunsmiths that do such creative work.

Being in the industry since 1984, I have had the pleasure of meeting many great people. One of those was Larry Kelly. Larry was a well-respected writer and renowned handgun hunter. Larry was the first hunter to take Africa’s Big 5 with a handgun. Larry also founded Mag-Na-Port International. Larry passed away in 2010, but his son, Ken, has continued his legacy and grown the business. Ken is one of those people who never meets a stranger and is very humble. He is also an extraordinary gunsmith.

What is Mag-Na-Port

Mag-Na-Port is a process where trapezoidal ports are cut in barrels using Electrical Discharge Machining. The process is very precise and does not damage the surrounding area or leave any burrs or machine marks. The ports vent gases upward which, in turn, reduces muzzle rise during recoil. Mag-Na-Ports do not reduce velocity, affect accuracy, or increase the report of the firearm.

The company offers a large number of services that include various port designs as well as custom gunsmithing options. For the past several years I have wanted to do a project with Ken. I was really waiting for the right pistol to send to him. When I received a new S&W Model 640-3, I knew the time had come.

The Centennials

The current Model 640 is a J frame, five-shot revolver, chambered in .357 Magnum. It features the completely enclosed hammer that S&W first introduced, in 1952, as the Centennial. The Centennials were offered with both a steel frame and an alloy frame and, in 1957, they became the Model 40 and Model 42 respectively. Both were discontinued in 1974.

In 1989, Smith resurrected the Centennial, with the stainless Model 640 that was rated for .38 Special +P. In 1996, Smith redesigned and strengthened the J-frame to accommodate the .357 Magnum cartridge. The Magnum Centennial was designated the 640. The Magnum J-frames are most easily identified by the longer, 2.125” barrel and the underlug that encloses the ejection rod.

The factory finish on the 640-3 is best described as semi-polished. The 640-3 weighs in at 22.1 ounces and is 6.5” in length. The trigger pull, while heavy, is smooth and the MIM trigger is void of any sharp edges. The front sight on all Magnum J frames is a pinned serrated black ramp. The pinned design makes replacement very easy. The soft rubber stocks are reminiscent of the old Smith banana grips and extend below the frame. Smith & Wesson 640 Factory Page

Designing a Custom Centennial

First off, I like the sleek lines of the Centennial and did not want to do anything that would detract from the pistol. I also wanted to show off the capabilities of Ken and the Mag-Na-Port shop. After talking with Ken, we came up with a build that was stunning but still very practical as a daily carry and personal defense handgun.

My first request was to bead blast the entire gun to give it a matte gray finish that was both attractive while being non-reflective. The second item on the build request was to do a deep inverted crown on the muzzle. This is a nice custom feature but also serves to protect the bore from damage. To complement the matte finish, Ken polished the sideplate screws and the thumb piece screw. He also polished a ring around the rear of the cylinder. This prevents the cylinder stop from creating a drag ring and is also attractive.

Going inside the pistol, Ken polished the appropriate parts and installed a lighter mainspring. To add to reliability, he installed a longer firing pin that was supplied by Cylinder & Slide. He also recut the forcing cone, honed the chambers, and chamfered and numbered the charge holes. The chamfering assists in reloads and the numbers are simply a nice custom touch. The factory front sight was replaced with a green XS Standard Dot with a Tritium insert. This is an easy modification since the factory sight blade is pinned in place. The result is a stunning little blaster that is suitable for a black tie event. He took the ugly MIM trigger and rounded the edges and polished it to a high polish. As a final touch, The Mag-Na-Port logo is etched on the sideplate.

A custom pistol requires custom stocks. I was fortunate to have a pair of Craig Spegel high horn boot stocks put back. They completed the transformation and are the perfect stocks to compliment Mag-Na-Port’s work. Unfortunately, Spegel stocks are extremely hard to obtain and his waitlist is over a year. Other options would be Altamont J Frame Stocks or Hogue Grips.

Range Time

On the range, I kept the shooting to .38 Special +P ammunition. I have shot Magnum loads from a J frame and it was harsh for both me and the pistol. Recoil was punishing and, regardless of what Smith chambered the 640 in, magnum loads are totally impractical for personal defense. However, for those who must know, Speer’s .357 Magnum 125 grain Gold Dot Short Barrel load averages a blistering 1,232 fps, from my Model 640 Pro.

I personally prefer a +P load that is specifically formulated for short barrels.

I chronographed three of the most popular personal defense loads through the 640, with the following results. It is important to note that not all loads will hit to the point of aim. Both the Speer and Federal loads hit close to the point of aim while the lighter Hornady load shot approximately 3” low at 10 yards.

Load	Average Velocity	Accuracy
Federal +P 130 gr. Micro HST	834 fps	2.2”
Speer +P 135 gr. Gold Dot Short Barrel	905”	3”
Hornady +P 110 gr. Critical Duty	880 fps	3.5”
Velocity measured at 10 feet/Accuracy from 7 yards

To Port or not to Port?

So, what about the ports? I shot my 649-5 as a comparison to the ported 640-3. Recoil and muzzle rise are both subjective and subject to grip, pressure, and the size of the hand. Being as consistent as I could, I found that the porting reduced muzzle rise by about 25% or so. This reduction was especially noticeable when shooting timed drills. When fired from a close retention position, the blast from the ports was noticeable but was not debilitating and I was not struck by any powder or jacket fragments.

The XS dot front sight takes some getting accustomed to. The dot is approximately twice the diameter of the rear sight notch. For close distances, inside 10 yards, the bottom of the dot ring can be placed in the rear sight notch. The hits will be slightly high but well within the vital area. For more precise shots, the Tritium insert is centered in the rear notch, with the lower half of the dot concealed.

Final Thoughts & Carry Options

Part of the joy in owning custom pistols is sharing them with your friends. The Mag-Na-Port 640 turned heads at the range and with my friends. Of course, a custom revolver deserves a custom holster. I carried the 640 in a custom IWB holster from my friend, Mark Garrity. The rig shown is gorgeous, comfortable, and durable. Garrity’s Gunleather

I wish to thank Ken Kelly and the entire crew for providing me with a truly custom revolver that will become a family heirloom. Mag-Na-Port offers a wide variety of options, port designs, and gunsmithing services. Visit them at Mag-Na-Port.

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