Cimarron’s .45 Thunderstorm Revolvers

When I first started competing in SASS some 23 years ago, cowboys and girls were using both original and replica sixguns. If you wanted a slicker action, chamfered chambers or other special features, you sent your gun to a custom gunsmith. Today, some CAS six-shooters, like many versions of the Model 1911 pistol, come straight from the factory with standard features that were once strictly extra-cost items that many times took weeks before completion and delivery. One of these new thumb-busters that is ready for competition right out of the box is the Thunderstorm from Cimarron Firearms.

RELATED STORY: Cimarron .45 Thunderstorm

Although this single-action revolver was designed primarily for the Cowboy Mounted shooter, is approved by the Cowboy Mounted Shooting Association and used by 2009 World Champion Kenda Lenseigne, I’m going to look at it from the “standing on my own two feet” perspective. The Thunderstorm is based on the Cimarron Model P or the Cimarron Thunderer, depending on whether you want a regular “plow-handle” grip or a bird’s-head grip. On the Cimarron website I noted that there were 22 variations of the Model P and Thunderer revolvers in .357 Magnum/.38 Special or .45 Colt with either 3½- or 4¾-inch barrels. They’re available with color casehardened/blued or satin stainless steel finishes.

Ready To Strike

One big difference in the Thunderstorm models is the manufacturer; you can get one made by Pietta or Uberti, both Italian arms-makers. The most glaring difference between the two makes is the walnut grips. The one-piece walnut grips on the Pietta models have checkering that includes a “triple-diamond” pattern and a laser-cut Cimarron Firearms logo. The one-piece walnut grips on the Uberti models have full-coverage checkering.

Both, however, have several common denominators. The first thing you’ll notice as you cock their hammers are the butter-smooth actions, which seemingly cock themselves. This comes about due to factory action jobs and U.S.-made competition springs. The SA trigger pulls on both guns have a bit of creep and overtravel, but their pull weights are about 4.5 pounds. While the triggers are of the traditional narrow variety, the hammer spurs—serrated on the Pietta and checkered on the Uberti—are wide for fast cocking. The front sights are wide, as are the fixed rear sight notches, for quick alignment during rapid-fire strings.

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One option you can have on the Pietta-made Thunderstorm is a short-stroke action. You get the same factory action job, but added to this is a hammer throw that is some 20-percent shorter than on regular SA revolvers. What this means to the competitor is a gun with a faster lock time, which translates to an increased accuracy potential, plus the short hammer throw makes for faster cocking, shaving off precious fractions of a second that could make all the difference. Experimenting with both empty revolvers at my desk, I noted that the Pietta short-stroke action on my blued test sample left the hammer in place at a better angle for my medium-sized hands to manipulate it than did the regular action, which places the hammer spur lower towards the rear grip strap. After dry firing numerous five-shot strings with empty guns, I got out my Pact timer to see which would be the fastest for five “clicks.” After ten attempts with each gun, the Pietta short-stroke action proved the winner by an average of 0.8 seconds. Not much, but I’m certainly no practiced speedster, and given the time savings over a match of several stages, it could be well worth it.

I tested a blued Pietta Thunderstorm  with a short-stroke action as well as a stainless Uberti Thunderstorm, both with 3½-inch barrels in .45 Colt. The Pietta has expertly polished bluing on the barrel, cylinder and grip frame, and the coloration of the casehardened frame and loading gate is very nice. The front edges of the cylinder, barrel and ejector rod housing are radiused to make holstering the gun easier, and the walnut grips are very attractive.

The Uberti is stainless with a nice polish, and the wood-to-metal and metal-to-metal fits were very good. Some of the stamping has been buffed off, but the radius on the front of the cylinder is good and the walnut grips are well done.

Punching Paper

I wanted to test the accuracy potential of the Pietta and Uberti Thunderstorm revolvers, so I selected four different brands of .45 Colt cartridges. There are a number of different players in the Cowboy Action Shooting ammunition game today, some might not be so well known, but I hope to help change that a little. One of the CAS standbys is, of course, Black Hills Ammunition, and my ammo locker supplied a couple of boxes of the company’s .45 Colt loads topped with 250-grain round-nose, flat-point (RNFP) bullets—a standard design for CAS, as they work well in tube-fed lever-action rifles and sixguns. Next was a 200-grain RNFP load from Bone Orchard. This weight produced a little less recoil and thus was faster shooting. Another well-known name in ammunition components and cartridges is Hornady, and its Cowboy line has a .45 Colt load with a 255-grain RNFP bullet. The Powder River Cartridge Company offers 200-grain RNFP .45 Colt loads in both its regular and Evil Roy Signature Series lines.

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At the range, I tested both of the Thunderstorm revolvers at 15 yards due to their shorter barrel lengths. I fired from a bench using a sandbag as a rest. Since both guns are very similar, I decided to concentrate on shooting the Pietta sixgun and do some limited paper-punching with the Uberti model. My point of aim was dead-center on two black squares I’d drawn on each of the silhouette-style targets. I was a bit surprised when the first shot actually hit closer to the lower square than it did the upper square. This was pretty much the same with all loads in both guns; I was getting hits anywhere from 5 to 7 inches low depending on the bullet weight. I therefore adjusted my point of aim for elevation; the windage was just fine for both guns.

The best five-shot group of the day, produced with Hornady’s Cowboy load, measured 1.59 inches. Second place went to the Bone Orchard cartridges, with a best group of 2.14 inches. The average for all loads ran from 2.36 to 3.25 inches.

To see what I might expect at a SASS match, I fired both revolvers off-hand at a steel “flapper” target at 7 yards, aiming anywhere from the top of the round flapper to an inch above it, and most shots hit on or just below the round target. I should note that the rear sight notch on the Uberti gun is a bit shallower than that on the Pietta, so the former didn’t shoot as low.

Action Shooting

I took the two Cimarron Thunderstorm revolvers to a Cowboy Action Shooting match to give them the “acid test.” But, as it turned out, it became more of an endurance test for me than for the guns. The day of the shoot was in late March, and spring took a backwards turn towards winter. When I arrived at the shoot site, the temperature was down to 22 degrees, and what had been wet ground was now frozen over. By the time we had the announcements, safety briefing and got organized, my toes and fingers were already getting numb! Since the weather was being uncooperative, we elected to shoot six main match stages; one of which included a running cowboy target that moved downhill and away from the shooter. I wore a rig with the Pietta Thunderstorm butt-rearward on the strong side (to make use of its short-stroke feature) and the Uberti Thunderstorm butt-forward on the opposite side.

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I didn’t really notice the guns shooting low at the distances involved in the first three stages. I’m not sure how much faster the Pietta was, but it was definitely easier to cock with the shorter action—especially with frigid digits! I also used it on the running cowboy, which I actually let move a few yards before I engaged it and still managed to make five well-centered hits before it reached the end of its travel. The last three stages had the handgun targets a bit farther out, and one was rather small, so here I had three misses with the sixguns. The checkered grips really made the guns easy to hang onto, and the lowered and widened hammer spurs made for rapid cocking with the support-hand thumb. Overall, I was very impressed with both guns, and I managed to snag first place in my category despite the match not being one of my best performances.

Sureshot Sixguns

I wasn’t sure how I’d like the short Sheriff’s-length barrels on these Thunder-storms, but I ended up finding them quick-handling and just plain handy. The brass from the various factory .45 Colt test loads dropped out of the loading gate easily, and there were only a few cases where I had to use the short ejector rods. Overall, I was impressed with both revolvers, and those short barrels are definitely what many Cowboy Mount-ed shooting competitors prefer. Not being equine inclined, I didn’t think they did so bad either with both my feet firmly on the ground. For more information, visit or call 830-997-9090.


Cimarron Pietta Thunderstorm Short Stroke

  • Caliber: .45 Colt
  • Barrel: 3½ inches
  • OA Length: 9¼ inches
  • Weight: 35.2 ounces (empty)
  • Grips: Walnut
  • Sights: Fixed
  • Action: SA
  • Finish: Blued, casehardened
  • Capacity: 6
  • MSRP: $748

Cimarron Uberti Thunderstorm

  • Caliber: .45 Colt
  • Barrel: 3½ inches
  • OA Length: 9¼ inches
  • Weight: 35.2 ounces (empty)
  • Grips: Walnut
  • Sights: Fixed
  • Action: SA
  • Finish: Stainless steel
  • Capacity: 6
  • MSRP: $948


Cimarron Pietta Thunderstorm Short Stroke .45 Colt

Load: Black Hills 250 RNFP
Accuracy: 2.86

Load: Bone Orchard 200 RNFP
Accuracy: 2.14

Load: Hornady Cowboy 255 RNFP
Accuracy: 1.59

Load: Powder River Evil Roy 200 RNFP
Accuracy: 2.89

Bullet weight measured in grains and accuracy in inches for three 5-shot groups at 15 yards.

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This article originally published in the Spring 2016 issue of GUNS OF THE OLD WEST®, print and digital subscriptions to GUNS OF THE OLD WEST are available here.

One Response to “Cimarron’s .45 Thunderstorm Revolvers”

  1. <cite class="fn">Freethink1</cite>

    The glaring difference I see b/w the Pietta and Uberti is the price. Is the Uberti really that much better?

    Another thing that confuses me about these Italian repros is that there are basically two manufacturers, Pietta and Uberti, However, it is difficult to figure out which one is which by comparing the Pietta and Uberti catalogs with the distributor’s (Cimarron, Texas Jack, Taylors, etc.) catalogs as they change the names and sometimes hide the manufacturer info.


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