Cimarron Firearms Thunderer 4 3/4
Image courtesy JWT for
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Cimarron Firearms’ Thunderer single action revolver is exactly like nothing they’ve done before. It’s kind of like everything they’ve been doing. And it’s awesome.

What’s so different about the Thunderer is that, unlike the other guns produced by Uberti for Cimarron, this one isn’t a reproduction. Cimarron goes through great pains to perfectly reproduce many historical firearms. I was duly impressed with the attention to historical detailed applied to Cimarron’s McColloch Colt.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

But the Thunderer never existed until now. Not exactly. The Thunderer is built off the Single Action Army. If you pulled the grip off, it would look just like the iconic Model Ps.

That familiar frame is paired with the grip from the double action Colt Model 1877, which was widely regarded as having one of the worst double action trigger mechanisms ever.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

Cimarron’s Thunderer is then a Single Action Army Top on a Model 1877 bottom.

This is the best mashup since Iron Horse’s Fade To Bluegrass.

Once you see it, and once you shoot it, you’ll wonder why this grip wasn’t put on a single action gun 100 years ago.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

In standard 14K PSI loads, the Thunderer is easy to draw and easy to shoot. There’s no twisting the hand common with the Model P. Pulling the firing hand up to cock the hammer isn’t a challenge, and since the frame is the same as the Single Action Army, it’s just as easy to cycle with your support hand thumb for fast fire.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

The website description and this stainless version are a bit at odds. Cimarron says the Thunderer is “made on the Old Model (pre-1896) frame and ‘bullseye’ ejector head.”

Note the cylinder base pin is held in by a spring-loaded cross pin on the side of the frame forward of the cylinder on this revolver. That’s a New Model/smokeless powder frame.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

The ejector head is definitely not the old model’s “bullseye,” but actually the half moon model, also from the New Model.

The discrepancy is because the blued models are built on the Old Model frame, and the stainless version is built on the New Model frame.

There are several finishes offered for the Thunderer. This particular model is their brushed stainless. As usual, Uberti does a great job here, producing a smooth, even finish without rough tool marks. It’s not quite the gloss you’ll find on a new Python or King Cobra, but it’s darn pretty nonetheless.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

The grip shape gives shooters with big hands a little more space between the front of the grip frame and the trigger.  It’s long enough that someone with size large hands can just fit 3 fingers fully on the grip, although many will still prefer to fire it with a “pinky under” grip common to the Model P.

These stainless guns come with smooth walnut grips adorned with the Cimarron medallion.  Checkered grips are also available.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

As the top is a standard Model P, you’ll find a bright blade fixed front and a channel rear.

The Thunderer’s critical dimensions are pretty tight. Using a minus pin gauge set, the cylinder throats all measured to .452″ and the minor bore diameter (lands) was .440″. The major bore diameter (grooves) measured to .451″. That’s all the right ratio for accuracy.  More importantly, considering the kind of shooting these guns tend to go through, those tight bore diameters mean a solid seal on a soft lead bullet, reducing fouling and leading of the barrel.

This was born out in the accuracy testing.

The common Winchester White Box 250gr Super-X round printed good and consistent 2-inch, five round groups when averaged over 4 shot strings at 25 yards off bags. This is a work-horse of a commercial cartridge, and I’d bet the most often shot round in the 45 Colt, at least for folks that don’t reload.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

For the decent, God-fearing Americans that roll their own, the Thunderer is capable of admirable precision.  One of my favorite loadings safe for any smokeless revolver is the Hunters Supply 255gr SWC over 6 grains of Titegroup.  At 25 yards this round will plow a tunnel straight through a broadside whitetail deer.  It also shot very well in this gun, producing extremely consistent groups that averaged 1.1-inch.

Given the critical dimensions of the Thunderer, I’d have expected those two similar bullets, firing at similar speeds, to print similar group sizes. They both shot to similar points of impact, less than an inch high and very slightly left at 25 yards, but the reloaded round obviously shot much better.  Maybe it has something to do with the material, as the Hunter’s Supply round has a Brinell hardness of 22, whereas the Winchester bullet is closer to 16.

I didn’t have any copper jacketed rounds in 45 Colt and I don’t see any need to have any.  A bullet with Brinell hardness of 22, especially when properly lubed, won’t foul your bore and will pound through flesh and bone just fine.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

The Thunderer shot with the reliability expected from Cimarron and Uberti, that is, exceptional. Uberti is extremely common on the SASS circuit. I’ve watched lots of folks shoot Uberti guns month after month in matches, and several national champions shoot their guns, for good reason. They work. They keep working. When, like all mechanical things, they break, they are easy and inexpensive to repair.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

Before I knew it, I had put 100 rounds through this gun. I did the same thing 3 days in a row, practicing a draw and fire 5 at various ranges. It was an absolute ball. It’s hard to not have fun shooting a cowboy gun, and the Thunderer is certainly no exception. I never had any issues with the revolver in any way. I lubed it well before shooting, and never again for the review.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

Cimarron has made a great revolver. It’s a little different than what they’ve done in the past, with the same eye to quality they’ve been putting out on their historical guns for decades.

I’m dreaming of what this gun would look like with full coverage engraving and some stag grips.

Cimarron Firearms Thunderer 4 3/4"
Image courtesy JWT for

Specifications: Cimarron Firearms Thunderer 4 3/4″ Stainless

Caliber: 45 Colt (multiple others offered)
Frame Material: Stainless steel (others offered)
Barrel Material: Stainless steel (others offered)
Barrel Length: 4 3/4″ (multiple others offered)
Weight: 2lbs (depending on barrel length)
Sights: fixed
Finish: Stainless (multiple others offered)
Grip: 1877 Birdshead
Grip Material: Smooth Walnut (checkered offered)
MSRP: $863.57

Ratings (out of five stars):

Style and Finish * * * *  
This thing looks great. Custom ideas abound. I’d like to see it with fancier wood.

Customization * * * *
Anything on earth can be done to this gun, and relatively inexpensively, considering how many parts and smiths there are available that know the platform.

Reliability * * * * *
I have a Uberti single action I literally found lying in mud after a flood. That was many years and many thousands of rounds through it ago. This one is even better.

Accuracy * * * * 
Good with the cheap store-bought stuff, and very good with the right round.

Overall * * * * ½
I can’t give a single action with less than stellar wood and a brushed finish 5 stars on principle. This is a fantastic revolver at a great price. Different, beautiful, tons of fun, and still practical 100 years after it should have been invented. The hard thing is finding one. Call Cimarron directly for availability.


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  1. My grandsons and I were in a Bass Pro a couple of months back. My 11yo saw a gun that looks like this, maybe it was the same make and model, and fell in love with it.

    Xmas rapidly approaches.

    • “Xmas rapidly approaches.”

      A gun for him that grandpa holds onto for while first?

      What I really wonder is, is there enough ‘meat’ in the metal for a .44 cal magnum version?

        • N-frames and the SAA have the same cylinder diameter, within several thousandths, varying from production run to production run as the tooling wears. Elmer Keith’s prewar experiments with SAAs in .44 Special and handloads of heavy cast bullets over terrifying amounts of old Hercules 2400 resulted in the .44 Magnum. Uberti makes a couple different models in .44 Magnum using this frame size. SAAs have cylinders around 1.650″ long, and SAAMI max cartridge length for the .44 Mag is 1.610″. It’s not as long as, say, a Redhawk cylinder, but it’s got room for the .44 Mag. A six-shot SAA cylinder in .44 Mag has significantly more meat between the chambers than a S&W 69 five-shot .44 Mag L-frame.

          With hot loads in magnum calibers, typically it’s the forcing cone that fails, not the cylinder. The cylinder isn’t something to worry about.

  2. Personally I am not a fan of the bird’s head grip. It just doesn’t fit in my hand well and puts pressure in the middle of my palm instead of spread out as with the standard grips. I also have a preference for Pittas mostly because their case hardened finishes are prettier, but otherwise the guns are almost identical. (They vary in the manner in which the hand plunger is mounted to the frame. Both have abandoned the original Colt leaf hand spring, a classic failure point.) I typically take the guns apart when new and polish the internal friction points with 2000 wet/dry paper. I’ve only had to tune one sear point, and that was on my Uberti. I haven’t measured trigger pull, but suspect it is fairly close to two pounds.

    These guns shoot great with standard “cowboy” loads, low pressure rounds that run around 650 to 750 feet per second. Minimal recoil, excellent accuracy. A huge amount of fun. I usually load between 7 and 9 grains of Unique over various bullets, both lead and JHPs.
    I’ve also loaded lubed 255 grain lead bullets over 40 grains of Pyrodex. BOOM! You immediately understand why the US Government had Colt download the rounds for military service to 35 grains. They really thump. That charge moves the velocity much closer to 1000 fps.
    If you skip the polished stainless and go for the blued finish, you can still find, if you look, either Piettas or Ubertis for around $550.

    • I don’t even know how they fit 40 grains of powder over a 255 gr bullet. Ive never been able to get it done.

      • What can I say. Black powder or substitute is pretty compressible. Also, the substitutes are about 25% lighter than true black, and may therefore be more compressible. My loads used Pyrodex. Original UMC loads used a 40-grain (2.6 g) powder charge and 255-grain (16.5 g) bullet. This was reduced to 35-grain (2.3 g) of powder, and later, by the Army, to 28-grain (1.8 g). Shooters typically find that 28 to 30 grains produces the best accuracy, such as is the case for the .44 1861 Army, another pistol designed for a capacity of 40 gr of black powder.

  3. “This is the best mashup since Iron Horse’s Fade To Bluegrass.”

    While quite good… 🙂

    There’s always 3 attractive Scottish lasses playing ‘Enter Sandman’ on the bagpipes :

    • There’s a deep rabbit hole of “wrong genre music” you can dive down if you so desire.

  4. Jon,
    Thank you for a nicely researched and written article. We’ll be slowly relocating to Texas for the next few years, and I prefer a SAA as a sidearm. My custom Bird’s Head in 44/40 is perfect, and BBQ fashionable; but this stainless six-shooter is also definitely real live art.
    Do you know if the cylinder backface has been modified with “Cups” to rest the firing pin in? You commented on the modernity of the design, and I don’t even know if the modification is possible in a 45LC cylinder, due to the thin web between cartridges.
    I doubt (but would be thrilled) if a fiber optic front sight would be offered. I know, I know…INFIDEL! My eyes just seem to need all the help they can get. I’ll find a pistol Smith, or just buy a small mill and tooling.
    In jest, if the digital markings on the front face of the loading gate is some secretive serial number, is the loading gate now the weapon they insist on registering? If so, 3-D printed loading gates, here we come!
    Thank you in advance for any answers.
    A spare-framed no-nonsense stainless SAA is the most desirable weapon that fits my hands.

    • No, no fiber optic sights, sorry, and the way the cylinder and hand is designed for both the original 1873 and these pistols is that there is no intermediate cup to test the firing pin. Moreover, the newer models by Pietta and Uberti have a floating firing pin that locks and allows a cartridge to fire only if the trigger is pulled. (Older models had various iterations of the Ruger transfer bar safety.)

    • A rattle can of flourescent paint will fix the front sight visibility problem. Just dutifully tape and paper up the surrounding area so you only get it where you want it. And an old toothbrush and acetone will clean it off, should you wish to avoid embarassment at parties. 🙂

    • Old ones three, new ones with the floating firing pin 4. The apparent purpose of the original Colt first click was to keep the firing pin off the primer if the gun was dropped. With the modern floating pin, that first click is essentially obsolete.

      • Old ones are 4 clicks as it spells C-O-L-T when you cock the hammer.
        New ones are 3 clicks because as you say, they deleted the first detent and added a floating firing pin the is pushed into play by the trigger being pulled.
        I asked because JWT did not specify which model is reviewed here.

        • How so? I have four. The two with transfer bars only click three times, the two with floating pins have four.

      • Mark, your original explanation confused me as well. When you said new versus old I assumed you meant new model versus old model, neither of which had a transfer bar, but now i get what you are trying to say.

    • The stainless version spells ABC, but since the blued models are built on the Old Model frame, they may spell COLT, but I don’t know.

  5. I have a friend who visited John Wesley Harden’s grave. Randy left a .45 LC cartridge on his tomb stone. Randy also picked up a pebble off the grave. It’s on his fireplace mantle today. A cemetery worker directed Randy to the grave. I suspect that man has a pocket full of rocks and plenty of free ammunition.

  6. No manual external safety? Dacian is out! How can such a dangerous mass murder machine ever be created, afterall what kind of maniac need six shots! The typical self defense gun use is three!!!

  7. I paid $5.17 for a large bag of tostitos corn chips.
    I was going to get a Pietta Colt clone today, no can do.
    Corn was ground up for silage because nothing on the cob Soy beans a bust, and if you run any cattle the pastures turn to dust.
    Let’s Go Brandon

  8. Will it take hot .45 colt rounds or best left to the cowboy loads? This looks like a fun addition to pair with my Henry big boy carbine if it will handle the hotter loads.

  9. 4 star customization is kind of a joke for something like this, isn’t it? By these standards everything is 4+ star as long as you have access to a gunsmith and machine shop.

    • Totally valid criticism. But I feel like these guns are so simple with so much information available about them, and so many after market products available for them that they are in a customization category of their own. You don’t need a gun smith and a machine shop, you just need youtube and some time.

  10. I own several SA revolvers. All are chambered in .38Spl/.357Mag. Inauthentic ammo, I know, but easier to find.

    In any case, single action revolvers take me home to the land of the Pecos . . . .

    Okay, that’s a western tv show lyric, but still.

  11. @EricInOregon
    As a design engineer:
    “Necessity is the Mother of Invention”
    “Don’t reinvent the wheel”
    “If it don’t work, fix it”
    “If it ain’t broke, DON’T fix it”
    “You know Engineers, they love to change things”
    phrases echo in my head. All the time.
    The DUMBEST ONE is:
    “Don’t do that, you’ll hurt the resale value”
    Working in a motorcycle shop, on occasion a customer would own a really great bike, but it “didn’t fit” him. I would offer that we could replace and/or adjust the bars, seat, foot pegs and controls to make it fit him to an absolute tee. Not ONE customer took this route, they wouldn’t even let me adjust the bars for them (yes, for free). In every case, they sold the near-perfect bike and bought something brand new, hoping for a better outcome!
    Things that are so close to you as a sidearm should have the same configurability. I’m not buying a pistol for someone else, it needs to fit ME. And my dim, myopic, glare offended, surgeried eyes. For example:
    My Moto Guzzi headlamp was junk. The stainless Kuryakin one was (back then) $325. K-Mart had a stainless bean pot for $25 and a $9 Pep Boys dual beam headlight RTV’d right in. Two days work boring holes for the instruments made for an antiquey looking headlamp that is in service to this day. Not Genuine Factory, just home made.
    To tell me my sixgun isn’t real genuine Cowboy is about as valid as telling a Trekkie speaking gibberish
    “Hey, that’s not REAL KLINGON!”
    I don’t care. It will be MINE, and it needs every advantage I can give it to do it’s job, in the worst scenario that it can be put into.
    No sidearms should be just BBQ Guns.

    • In the context of replying to my comment, I literally can’t figure out what point you’re trying to make here.

      • My reading is that he’s jealous that you have a nice bbq gun and he just has an old moto guzzi with a nine dollar headlight.

  12. Excllent review. Loading only five rounds isnt a drawback. While I own a very nice Traditions with transfer bar ignition, safe to load six rounds, I find the original with hammer mounted firing pin just feels nicer. Since they are not intended for serious work any more all good.

    On the subject of loads — A 250 grain SWC hard cast at 830 fps is a very good load for these. If you can find primers.
    Keep writing and keep it coming the cowboy guns.

  13. 4 star customization? Hell yeah. Many springs and grips available if you need them, probably wont with this gun.

    Actually I think I might have went a 2.5

  14. This is being written from my solitary confinement cell in Moderation Jail…
    I must strongly disagree with the notion that only factory produced aftermarket modification parts (which happen to be available in exchange for your cash) should be applicable to a Single Action Revolver.
    Lights, Lasers, Fiber Optic and Night Sights, Grips and cool stuff all enhance Autos.
    Yeah, I know, magazine funnels and extended slide stops, etc. won’t fit my SAA or even my model 64 with a gutter rear sight.
    What do we revolver guys get? Grips.
    I don’t want my sights regulated at 25 yards. Holding over obscures any target past maybe 80 yards. You have to find something over where you remember where the target was two seconds ago and fire at that. Kinda like Naval Gunfire.

    Why no light on my SAA? “Doesn’t look period correct”? Puhleeze…
    Really, what is this push back that demands that you can’t butcher up your own single action sidearm to be more ready for 24/7 duty? Just mansplain it to me.
    And yes, I already designed the light…

      • JimSimpsom: I deeply appreciate any designer that thinks so far out of the box that it is a novelty for them to actually step into it. Just for fun. To see what the 99% are seeing. Kudos!
        Your pistola is pure and functional art. It also tosses the definition of “Revolver” right out the window. I should be so brave!
        Don’t even think about listening to your detractors. One of your features may become the “Next Big Thing”.

        • Here’s the crazy part. There’s a production military to this design.

          Late in WW2 as the allies were finding weird ass German weapons all over the place, they found a stash of single action revolvers – the Mauser MG 213.

          It was about 7ft long, 5ft barrel, five shot cylinder as big across as a bowling ball and chambers with 5 rounds of 20mm autocannon. It was also belt fed. It had a big thing in the rear that went back and forth, curved around so it was both the shell rammer on one side and the mechanical extractor on the other. Rounds would be crammed into the rear of the cylinder before the firing position and stripped out after the firing position. Each cylinder chamber rested and cooled for four positions before firing again. The rammer/extractor went back and forth under gas pressure from the firing chamber, which ejected the previously fired shell in the sequence.

          It’s highly resistant to jamming because it seriously doesn’t shit where it eats.

          That German gun was copied by the US as the Pontiac M39 and we used it in the F86 and other early jet fighters. Britain called their version the ADEN gun. France and Russia had versions too.

          There’s a company in England still making the ADEN gun. They’ve confirmed by email that Maurice technically falls into this family of guns as the feed cycle is the same. It’s the only personal arm with this feed cycle ever made, until I finish Abomination of course which will have a real shell rammer instead of the spring loaded tube mags in Maurice.

          And yes, Ian says he wants to play with them :).

      • I like the careful juxtapositioning of the micrometer beside the multitool. Fits the theme.

  15. I’ve got the Uberti 1873 bird’s head with the 5-1/2″ barrel. Searched around on the interwebs for 2 years before I actually found one. Still a relative bargain at ~$450. Love it, hammer drops with exactly 2# of pressure. And Fade to Bluegrass. Might recommend Steve’N’Seagulls, Luther Wright and the Wrongs and of course, if you haven’t heard The Gourds rendition of Gin and Juice you just haven’t experienced much in life yet now have you.


  16. You’re right, I went on and wasn’t clear.
    My question is why there is push-back from people when you want to butcher up a Single Action. Frankenblastering your auto is seen as normal, even desired. Filing down a front sight on a period reproduction SAA is looked upon as travesty. Actually, I have been told more than once that they were made oversized for this purpose.
    Thank you for commenting and pointing out the lack of clarity in my rant. I’ll be more focused next time.
    I’ve been shade tree re-engineering stuff since I wuz a teenager. When you are perennially broke, it comes naturally.

    • Typically, filing down of the front sight is only done in grizzly country and for good reason.

  17. remove the ejector rod and install a Lasermax if you wanna be a moron
    Have fun and wear a SAA hiking

    If you need a gun for your own sake carry a Glock

  18. @VC:
    Yes, I carry a Glock 43 w/nightsights and one reload. XLNT piece. I just feel like my hand was meant for a plowhandle or birdshead. Maybe it’s because I wuz brought up using a Ruger SBlackhawk. I’ll rephrase the question:
    “What about a standard weapon upgrade feels so inconsistent to most shooters?”
    And WHY?
    I myself “have this feeling” that it’s inherently wrong somehow. Why?
    BTW, the purpose of the weapon is mainly nightstand or “perimeter patrol” at home.
    My pistola league does night shoots, but requires a hand-held flashlight – no night sights or weapon mounted lights. Probably IPSC rules, I dunno. My personal stuff has sights and/or lights.
    Question still stands…

  19. I meant “Standard weapon upgrade” usually applied to an auto, but instead applied to a revolver. Single or double action, with factory primitive sights. Sorry for the dumb omission on my part.
    English is my second language. Finger Painting is my native tongue…

  20. No, the four clicks do not “spell C-O-L-T.” Just stop saying that. They don’t “spell” anything. Geez.

  21. Mammoth ivory is banned in CA? What, are they an endangered species? F*ck, we used to steal petrified wood from the Nat forest in AZ. You can’t wade into La Brea and pluck elephant tusks? Must be banned in the wonderfully amusing Prop 43.

    • Elephant, walrus, mammoth, hippopotamus, warthog, and whale ivory….if it is ivory, it is banned. To save the species or something. If I read the law correctly, you can even have ancient ivory that has been in your possession for years seized as contraband. It is possible that you can’t even import an 1873 manufactured at the turn of the (20th) century that was built with ivory grips.

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