Ruger GP100 “Wiley Clapp” 357 Magnum Revolver


by Jeff Quinn

photography by Jeff Quinn & Boge Quinn

August 16th, 2011


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Ruger GP100 "Wiley Clapp" 357 Magnum revolver.



GP100 comes with hard case, instruction manual, and padlock.



Synthetic rubber grips with wood inserts.





Sights are square post front with fiber-optic insert, and Novak drift-adjustable rear.









The Ruger GP100 has been in production for twenty-five years now, replacing the dandy Security-Six/Speed-Six/Service-Six line of double-action revolvers. Replacing the Six series, it had big shoes to fill, but has proven a worthy replacement, stronger than its predecessor. The GP100 is about as rugged and reliable as you can get in a 357 Magnum double-action revolver. The GP100 is a gun that you can buy and shoot all you want. Full-house 357 Magnum loads can be used with no limitation on the number of rounds that you can feed through the sixgun. With the GP, you do not have to worry about cracking the forcing cone, or the revolver getting out of time. Just shoot it, then shoot it some more. The GP100 has a solid frame design, meaning that there is no side plate. The internals are removed through the bottom, with most connected to the trigger guard. These are tough, reliable revolvers, balance well, and are compact enough to serve as a duty gun, and also for concealed carry, properly holstered.

The latest in the GP100 line is the Wiley Clapp GP100. Wiley Clapp is a gun writer who has been at his craft for many years, and worked with Robert Coyle of TALO, Inc. on the features and specifications of this particular version of the GP100. Most noticeable is the good-looking matte stainless finish, and the handsome checkered wood grip inserts that are inset into the one-piece synthetic rubber grip. The GP100 grip is very comfortable when shooting heavy magnum loads, and the design of the grip panels puts the checkering on the portion of the grip that is just underneath the shooter’s fingers. The sights are different than on other variations of the GP100. The rear is a rugged Novak unit that is adjustable for windage correction, and the front blade has a green fiber optic rod, for better use in low lighting conditions, while still retaining the squared profile preferred by most target shooters. This GP100, while it would serve as a hunting tool, is built for defense, and it is well-suited to the task.

The 357 Magnum has been proven on the streets and in the back alleys for decades. The cartridge has a very good reputation for bringing a fight to an end. The 125 grain jacketed hollowpoint is my favorite bullet for social work in the 357 Magnum, and this special version of the GP100 is a very good platform from which to launch that bullet. Many folks these days think that one must have a high capacity magazine holding a score of cartridges, but the fact is that most handgun fights are over within the span of a couple of seconds, with few shots fired. The 357 Magnum is as good as it ever was as a fight stopper, and a good, reliable revolver makes for an effective weapon in a gunfight. Another advantage of a revolver that is seldom mentioned out of political correctness, is that the revolver does not leave the empty cartridge cases lying on the ground as does an autoloader. Even in a justified self-defensive shooting, there are some jurisdictions in which a person will be prosecuted by the law for using a firearm in defense of his life. In such a situation, you do not want to leave cartridge cases on the ground that have your finger prints upon them. A semi-auto flings its empty brass upon the ground. The GP100 does not. Usually this is not a concern, but there are some areas in which, even if morally justified to do so, using a handgun to defend yourself or someone else will get you time in prison. It ain’t right, but that’s the way it is. In such areas, you do not want to leave evidence at the scene of even a justified shooting. Anyway, if you choose to carry a revolver for whatever reason, the GP100 is a fine choice, and the three-inch barrel of this GP is a good balance of portability and power. The Novak rear sight, combined with the fiber-optic front is a good sighting combo for defense, and a Crimson Trace Lasergrip is easy to add, if desired.

Like any modern double-action revolver, the GP100 is easy to use, easy to load, and easy to maintain. The GP100 can be fired with a long pull of the trigger (double-action) or by first thumb-cocking the hammer for a light, crisp trigger pull (single-action) In a gunfight, double-action is best. The weapon is drawn from the holster, aimed, and the trigger is pulled. No safeties to manipulate at all. Just point and shoot. When finished, place the weapon back into the holster. The manual-of-arms is very simple with a double-action revolver, and it is easy to determine whether or not the weapon is loaded, even by a novice shooter.

The detailed specifications of the Wiley Clapp GP are listed below. All linear measurements are in inches, and the weight is listed in ounces. The trigger pulls are listed in pounds of resistance. SA is the single-action trigger pull. DA is the double-action trigger pull. Height includes the sights.

Weight 37 oz.
Barrel Length 3.07"
Trigger Pull SA 4.4 lbs.
Trigger Pull DA 8.4 lbs.
Cylinder Length 1.61"
Cylinder Diameter 1.55"
Chambers 6
Overall Length 8.5"
Overall Height 5.57"
Barrel/Cylinder Gap 0.005"
Ammunition 357 Magnum / 38 Special

For accuracy and function testing, I tried every type of 357 Magnum factory ammunition that I had available to me, as well as the Stryker 38 Special hollowpoint load. The ammo consisted mostly of high performance ammunition, along with one of my favorite cast bullet handloads that I use as a general purpose plinking and casual target load. This moderate handload uses the excellent Mt. Baldy 173 grain plain base Keith semi-wadcutter bullet with six grains of Hodgdon Titegroup powder. The accuracy of the GP100 was tested using my Ransom Master Series machine rest. The chronograph and accuracy results are listed in the chart below. JHP is a jacketed hollowpoint bullet. SP is a jacketed soft point bullet. DPX is a homogenous copper hollow nose bullet made by Barnes Bullet Company, and loaded by Cor-Bon. Glaser is a specialty jacketed bullet with a compressed pre-fragmented core. PB is Cor-Bon Pow’RBall. HC is a hard-cast lead bullet. Keith is the aforementioned semi-wadcutter cast lead bullet. Velocities were recorded at a distance of twelve feet from the muzzle, and are listed in feet-per-second (fps). Bullet weights are listed in grains. Accuracy results listed are the average of the five-shot groups fired at a distance of twenty-five yards, listed center-to-center of the widest apart bullet holes in each group. Group sizes are listed in inches. Testing was done on a calm day with a slight breeze and an air temperature in the eighty degree Fahrenheit range, at an elevation of approximately 541 feet above sea level, and relative humidity of sixty-two percent.

Ammunition Bullet Weight Velocity Group Size
Cor-Bon HC 200 1023 1.90"
Cor-Bon JHP 110 1421 2.40"
Cor-Bon PB 100 1560 2.80"
Cor-Bon JHP 140 1214 2.90"
Cor-Bon DPX 125 1290 2.75"
Cor-Bon SP 180 1146 2.10"
Cor-Bon JHP 125 1301 2.10"
Cor-Bon Glaser 80 1731 3.80"
Buffalo Bore JHP 125 1440 2.00"
Buffalo Bore JHP 170 1127 2.25"
Buffalo Bore JHP 158 1223 1.68"
Buffalo Bore HC 180 1251 1.75"
Grizzly Cartridge HC 180 1134 2.60"
Handload Keith 173 1009 2.25"
Stryker 38 Special JHP 158 760 0.51"

Accuracy varied from good to amazing with the GP100. As mentioned above, all accuracy testing was done at a distance of twenty-five yards, with the revolver secured into my Ransom Master Series machine rest. With most all ammo tested, the GP100 fired very good five-shot groups. With the Stryker 38 Special ammo, this GP100 would cluster into a half inch or less, with every group fired. I was surprised, as this is some low-priced ammo, but it uses good hollowpoint bullets. That load is not up to 357 Magnum velocities, but it has low recoil, and makes for a dandy low-cost practice load.

The Wiley Clapp GP100 is a limited-production variation on that fine Ruger double-action design, and is exclusive to TALO wholesalers. However, with several wholesalers in the TALO group, just about any gun dealer can get one for you. The GP100 is a good, rugged, powerful, and reliable 357 Magnum revolver, built right, and built in the USA.

Check out the extensive line of Ruger firearms and accessories online at

For the location of a Ruger dealer near you, click on the DEALER FINDER at

To order the GP100 online, go to

Check out Bob Mernickle's line of holsters at

To order premium quality 357 Magnum ammunition online, go to

To order a variety of 357 Magnum and 38 Special ammo at an affordable price, go to and

Jeff Quinn

NOTE: All load data posted on this web site are for educational purposes only. Neither the author nor assume any responsibility for the use or misuse of this data. The data indicated were arrived at using specialized equipment under conditions not necessarily comparable to those encountered by the potential user of this data.  Always use data from respected loading manuals and begin working up loads at least 10% below the loads indicated in the source manual.

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Click pictures for a larger version.






Mernickle crossdraw holster.



Cylinder is plenty long for even the Buffalo Bore 180-grain cast bullet ammo.



Accuracy testing was done at twenty-five yards using a Ransom machine rest.