Ruger GP100 Optic

I have a stainless steel Ruger GP100 chambered in 357 Magnum with the six-inch barrel. The iron sights are fine but I wanted to shoot more accurately at longer distances. I decided to add along eye relief scope to improve my accuracy beyond 25 yards. For those not familiar with the GP100, here’s a little background. The GP100 is a family of double action revolvers that succeeded the Security Six series. Ruger strengthened the frame and action; the cylinder is locked into position at the front, rear, and bottom.

The GP100 is available in several calibers, barrel lengths, and in blued or stainless steel. My GP100 weighs 48 ounces loaded with the ammo used in the test. The single action trigger pull averaged 4.5 pounds and the double action pull was 10.7 pounds. It has the Hogue grip which reduces felt recoil. After some searching on the Internet, I found the "Weig-a-tinny" scope mount made by Weigand Machine and Design (Jack Weigand. com) intended for the Ruger GP100.

The mount accommodates Weaver and Picatinny scope rings and is available for the GP100 with 4", 4.2", and 6" barrels. It’s aluminum, weighs 3.1 ounces, and ships with the required hardware. The mount utilizes the GP100 front The machining quality is excellent.

and rear sight mounting locations and does not require any modifications to the revolver. Installation The front and rear sights are easily removed. The front sight has a springloaded pin in its base; push in on the pin, lift the rear of the sight blade and pull it to the rear to disengage the lip at the front. The rear sight has across pin that is drifted out, right to left. Turning the elevation screw counter-clockwise on the top of the sight allows it and the sight to be removed.

There are two springs under the sight; be sure to capture them. I clamped the pistol frame in a soft jawed vise after removing the grip so I could have both hands free. Weigand provides an excellent set of instructions and I’ll cover the main points. The scope mount utilizes a small steel block that fits into the front sight location and is retained by the spring-loaded pin. The block has two tapped holes that secure the front of the mount.

The rear of the mount is secured by a screw inserted into the rear sight elevation screw hole. The tapped holes and the screws need to be degreased before assembly. The rear sight notch acts as a recoil lug so the scope mount is pushed and held forward against the notch and the rear screw and washer are installed first. Use thread locker and tighten the screw until snug and then back out 1/4 turn. The two front screws are installed with thread locker, tightened until snug and then backed out 1/4 turn.

These screws are then tightened until snug, and the rear screw is snugged down. Tighten the screws to 20 inch-pounds or about another one-eighth of a turn. The rear screw is 6-40 thread, and the front screws have 6-48 threads and require 3/32" and 7/64" hex head wrenches, respectively. The rear screw is longer than the other two and careful inspection is required to ensure it doesn’t protrude into the cylinder opening. If it does, it will need to be shortened.

The mount should not touch the barrel other than at the front block. I checked the fit up of the parts before adding the thread locker. There were no issues and the installation was easy. Weigand recommends checking the screws for proper torque after 12 rounds and again after another 12 rounds and then after every 50 rounds for 150 rounds. After installation, the mount was very solid. Weigand offers scope mounts, both drill & tap, and no drill-no tap for a variety of handguns. There are

Spring loaded pin is pushed rearward to release sight blade, sight blade is lifted at rear and pulled rearward. The original ramp sight blade was replaced by the light tube shown. Drift out the cross pin, right to left, turn elevation screw CCW to remove it. Be sure to capture the two springs under the sight assembly. The tapped hole needs to be degreased. "mini-mounts" for Ruger revolvers that position ared dot on top of the frame. The machining on the mount was excellent.

At the Range I wanted to determine how much I could improve my longer distance shooting with optics. I had depleted all my 357 Magnum rounds and most of my 38 Special awhile back and had not restocked. Ammo is starting to become available again, however, 357 Magnum ammo was not to be found anywhere and the 38 Special selection was very limited. I used a 38 Special load with 158 grain full metal jacket round nose bullets for all the tests.

Obviously, I wanted to see if the scope mount stayed firmly attached with 357 Magnum but that will have to wait until another time. The mount screws did not loosen during the tests so I doubt there will be an issue later. When shooting rifles, I typically shoot four groups of five shots and average the groups. More recently, however, I have been shooting three groups of three shots due to the lack of reloading supplies. I decided to fire three groups of three rounds at each target for this test to conserve ammo.

I fired all the rounds in single action. I initially documented my accuracy with the GP100 at 15, 25 and 50 yards with the iron sights. The barrel was supported by an adjustable rest and the butt of the revolver sat on a rear bag for all the tests. The groups averaged 1.73", 3.01", and 7.84" at those distances. After installing the scope mount, I decided to try a Bushnell TRS-25 red dot first since it had improved my accuracy at longer ranges on a rimfire pistol, especially when shooting offhand.

The red dot eliminates the need to align the front and rear sights with the target. After sighting in, I shot groups at the same distances. Those groups averaged 1.45", 2.81" and 5.49". There wasn’t much difference at 15 and 25 yards but some improvement at 50 yards.

I then installed a BSA Edge 2-7×32 pistol scope. I chose this scope based on the price and favorable reviews. It weighs 10.7 ounces and the quick detach rings added 6 oz. I sighted it in and then shot groups at 15, 25 and 50 yards. The groups averaged 1.41", 1.72", and 3.55". This was a 43% improvement at 25 yards and a 55% improvement at 50 yards when compared to the iron sights.

There was no real difference in group sizes at 15 yards which is not surprising at such close range as even the scope’s 2X setting was too much magnification and the red dot was easier to shoot at that distance. The vertical and horizontal lines on the scope reticle were narrower than the red dot and helped me zero in on the center of the targets. I noticed that the field of view on the extended eye relief scope was smaller than with rifle scopes which I assume is typical.

Shooting with both eyes open helped, as it did with the red dot. I shot offhand after each of the accuracy tests. The red dot and mount added six ounces to the GP100 which wasn’t really noticeable. The scope and its mounts added 16.7 ounces, turning a 3 pound handgun into a 4 pound handgun. That was noticeable. I found it easier to hold the gun on target with the red dot due to the lighter weight.

The GP100 is capable of better accuracy, the bench rest and the offhand shooting revealed that I need to spend more time on dry fire and live ammo drills. I’ll try different ammo, including 357 Magnum, when it’s available.

Ruger GP100 (Speci ications subject to change without notice) 1 Barrel 2 Center Pin Lock 3 Center Pin Rod 4 Center Pin Spring 5 Crane & Crane Pivot Assembly 6 Crane Latch Pivot 7 Crane Latch Spring Plunger 8 Crane Latch Spring 9 Crane Latch 10 Crane Pivot Lock Plunger / Spring 11 Cylinder 12 Cylinder Latch Pivot 13 Cylinder Latch Plunger 14 Cylinder Latch Spring 15 Cylinder Latch 16 Cylinder Retaining Ball (2 Req’d) 17 Disassembly Pin 18 Ejector 19 Ejector Alignment Pin (2 Req’d) 20 Ejector Retainer 21 Ejector Rod 22 Ejector Spring 23 Firing Pin Rebound Spring 24 Firing Pin 25 Front Latch 26 Front Latch Pivot Lock Spring Optics don’t necessarily make you shoot better; they help you see better.

This allows you to be more precise in your shot placement.

The "Weig-a-tinny" scope mount was easy to install and provided a very 27 Front Latch Pivot Lock 28 Front Latch Pivot Pin 29 Front Latch Spring Plunger 30 Front Latch Spring 31 Front Sight – Front Sight Cross Pin, NI 32 Front Sight Plunger 33 Front Sight Plunger Spring 34 Grip Ferrule, Left 35 Grip Ferrule, Right 36 Grip (One Piece) 37 Grips 38 Grip Panel Locator 39 Grip Panel Screw 40 Hammer 41 Hammer Dog 42 Hammer Dog Pivot Pin 43 Hammer Dog Plunger 44 Hammer Dog Spring 45 Hammer Pivot Assembly 46 Hammer Strut 47 Hammer Strut Mainspring 48 Hammer Strut Seat 49 Pawl 50 Pawl Plunger 51 Pawl Plunger Spring 52 Rear Sight Complete 53 Rear Sight Base 54 Rear Sight Blade 55 Rear Sight Cross Pin 56 Rear Sight Elevation Screw 57 Rear Sight Elevation Spring (2 Req’d) 58 Rear Sight Windage Adjusting Screw 59 Rear Sight Windage Spring 60 Recoil Plate 61 Recoil Plate Cross Pin 62 Transfer Bar 63 Trigger 64 Trigger Guard 65 Trigger Guard Latch 66 Trigger Guard Latch Pin 67 Trigger Guard Latch Spring 68 Trigger Link 69 Trigger Link Pin 71 Trigger Pivot Pin 72 Trigger Plunger – Safety Insert, NI (Plastic Disc) solid base for attaching optics to the GP100.

It is well made and is not expensive. Installing the red dot and scope helped improve my accuracy at longer distances. They’ll probably help your customers as well. AG American Gunsmith Reader Services 1.