Ballistics by the inch

What a difference just an eighth of an inch makes.

Recently I came across on a surprisingly good deal on a Taurus Tracker .44mag snubnose. This one:

Taurus isn’t my first choice of firearm brands, but I’ve owned them and generally liked them, and the price on this one was a little too good to pass up. So I got it, figuring that it would be an interesting addition to my collection, occasionally using it as a carry gun.

After shooting it with a variety of .44special and .44mag loads that I had on hand, I decided that what I wanted to use as a carry ammo was something we’d tested: Corbon’s 165gr JHP.  The lighter weight bullet would mean a lower felt recoil. And I knew how it would perform out of a short barrel, and estimated that I would get about 1150fps and just under 500ft/lbs of muzzle energy from the round. I checked locally, and the ammo wasn’t available, so I ordered in five boxes from a source online.

When it arrived, I did the logical thing and inserted five rounds into the Taurus, then closed the cylinder.

Er, make that I *tried* to close the cylinder. Because it wouldn’t. Huh?

I examined the gun. I had not noticed that the cartridges hadn’t gone completely into the chambers. The rims of the cartridges were all about 1/16th inch out.  Oops. That was a mistake on my part — I should have been paying closer attention when handling the new untested ammo, rather than just assuming that it would load properly. This is what it looked like after I removed one cartridge for contrast:

 

Even lightly tapping the cartridges wouldn’t get them to load properly (where the rim is down on the rear cylinder face). I removed the rest of the cartridges, examined the gun to make sure everything was otherwise functioning properly. It seemed to be. I looked over the cartridges, and they seemed to be fine, as well. So I got a couple of different .44 loads — a mix of .44sp and .44mag — and put them into the cylinder. They all loaded just fine, the cylinder closed, and there were no problems. Here are a Hornady and a Winchester .44mag round in the cylinder, with one of the Corbon; note the difference:

 

Hmm.

Next, I got my Colt Anaconda .44 out of the safe. I tried the same ammo in it, and this is what I found:

Exact same problem. So, presumably, it was the Corbon ammo. I removed the rounds from the gun.

And grabbed my digital calipers. I started checking all the dimensions on the Corbon ammo. In fact, I went through and checked several sample cartridges from all five boxes. As far as I could tell, everything was in spec. The cases were the exact correct length. And width, both at the mouth of the case, along the body, and just above the rim. The bullets were the correct diameter. And the over length of the cartridges was well within the normal range of .44magnum rounds.

WTH?

I set the conundrum aside, so my subconscious could chew it over for a few hours. The likely explanation hit me while taking a shower the next morning. Here, look at the images of the three different rounds mentioned above, and see if you can spot it:

Here’s a hint: the Corbon cartridge is in the center.

Got it?

Yeah, if you look very carefully, you’ll see that the SHAPE of the Corbon bullet is different than the others. Note how it almost swells a bit, going up from the mouth of the case, to about an eighth of an inch, before narrowing down. Whereas the Winchester (on the left) and the Hornady (on the right) both have a smooth ogive right from the mouth of the case until coming to a flat nose (actually, the Hornady, like the Corbon, is a hollow point, but you can’t see that from this image).

So why did this cause the problem?

The explanation requires a bit of detailed knowledge about how a revolver works. If you already know all this, my apologies. For those who may not …

Each chamber in a revolver has to be big enough to accommodate the case of the cartridge. But the bullet is slightly smaller than that, so that it fits inside the cartridge case.

Now, when a chamber on a revolver rotates into position aligned with the barrel, there’s always a chance that it might not be perfectly aligned. Just a few thousandths of an inch misalignment can lead to all kinds of bad things happening, from parts of the bullet being shaved off and spit out the sides of the ‘cylinder gap‘ to the gun going KABOOM in your hand. So revolver manufacturers have come up with two nifty ways to deal with this:

  1. Narrowing the chamber in front of the cartridge case slightly by tapering it.
  2. Having a ‘forcing cone‘ before the barrel that is just a little bit bigger than the bullet, to funnel it into the barrel.

So, the problem with the Corbon ammo was that shape of the bullet in the pic above. Note how it doesn’t smoothly curve in like the other two bullets. Rather, that slight swelling is probably hitting the taper inside the chambers, stopping the cartridge from seating properly.

And before you say that this is a problem with the Taurus being poorly made, note that I ran into the exact same problem with my Anaconda — widely considered a very good quality gun.

Now, the folks at Corbon are smart. I’m sure their engineers actually tested this ammo in some typical .44magnum revolvers. But all it would take is for slight differences (think a couple thousandths of an inch) in the rate or position of that chamber tapering from manufacturer to manufacturer to cause this problem. Chances are, they just didn’t test it in a Taurus .44 of this model, or a Colt Anaconda. It is also possible that this batch of bullets (all five boxes I got are from the same lot — I checked) is just slightly out of spec, but no one has yet noticed it in their guns, because the tolerances in other manufacturers are a little bit different.

Either way, I’m fairly sure that I could just take some sandpaper or a fine file to that slight swelling on the bullets, and they’d fit right into my gun. But first I’m going to wait and see whether I hear back from Corbon about this issue (yeah, I sent them an explanatory email a couple days ago).

Oh, one last thing: in the process of going through all of this, I noticed that the cylinder length (from the front face to the rear face of the cylinder) on the Taurus was 1.625″, or 1 5/8″, whereas the cylinder length on my Anaconda is 1.75″, or 1 3/4″ — an eighth of an inch difference. As I recall, 1.75″ is standard for .44magnum revolvers. Interesting that the Taurus is slightly shorter, and that may indeed have had something to do with the shape of the chambers on the gun.

Edited, 2/27: Just a quick note. I’ve had some friends check other brands of .44mag revolvers. Seems that Smith & Wesson makes theirs with a cylinder length of 1.6875″ (1 11/16th”), and Ruger 1.75″ (1 3/4″). So there’s more variation than I thought.

 

Jim Downey

February 26, 2020 Posted by | .44 Magnum, .44 Special, Anecdotes, Data, Discussion., Revolver | , , , , , , , , , , , , , , , , , , | Leave a comment

Reprise + New Review: Uberti Lightning and Taurus Thunderbolt pump carbines.

Prompted by my friends over at the Liberal Gun Club, this is another in an occasional series of revisiting some of my old articles which had been published elsewhere over the years, lightly edited or updated with my current thoughts on the topic discussed. This is an article I wrote for Guns.com, and it originally ran 2/27/2012. In addition, I am including a new but related review of the Taurus Thunderbolt following the original review.

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I have owned several lever guns over the years—a style I deeply enjoy. Currently, I have a Winchester 94AE in .44 magnum, which I love. However, I always keep my eyes open for a lever gun in .357 mag. It’s a cartridge that really begins to shine when paired with a carbine length barrel. Based on BBTI testing, it gains upwards of 50 percent velocity and pushes 1,200 foot/pounds of muzzle energy. But then the Uberti Lightning came into my life—a .357 pump carbine—and I wasn’t quite sure how to feel.

Don’t Forget Where You Come From

It’s a reproduction of the original Colt Lightning, originally manufactured in 1884 (but, curiously, listed as the Model 1875 by Uberti), and a pretty faithful reproduction at that. The only changes it has are to meet modern safety demands. Specifically, there’s a new hammer safety (of the transfer-bar variety), which eliminates the option to fire the gun just by pumping new rounds while keeping the trigger pulled. This also greatly reduces the chance of an accidental discharge.

Uberti Lightning

The Uberti Lightning I shot was the ‘short rifle’ version, meaning it has a 20-inch barrel, with a case-hardened frame and trigger guard. It’s a very attractive gun with a top-notch fit and finish, a beautiful walnut stock—smooth in back and checkered on the slide—and good detail work. The case-hardening is quite attractive, but the gun is available in just a blued version if you prefer.

When first loading the gun I experienced a common problem that Uberti cautions about (and something I was warned about by several other reviewers): it is relatively easy to get a cartridge wedged under the carrier that loads a round from the tubular magazine into the chamber. This can also happen when you cycle the gun, if you’re not careful to push the slide grip fully forward and fully back. I wasn’t the only one of the three of us trying the gun who had this problem, and each time we had to stop, dislodge the cartridge with a small screwdriver, then cycle the action fully.

It’s a flaw in the design, there’s little doubt about that. However, once we all got the hang of it, we had no problems firing the gun quickly and accurately.

And I think that is the nicest thing about the Lightning: once you learn how to use it, it is faster and easier to stay on target than using a lever gun, at least for me. And I have a fair amount of experience shooting lever guns. You can run through 10 rounds almost as fast as you can pull the trigger.

Shooting

The gun shot well, and was very accurate. At 25 yards (the longest distance we had available) it was no challenge to keep rounds in the X. Others have reported that it is just as accurate out to 50 yards, and I have no difficulty believing that.

Recoil is minimal, even with ‘full house’ 158 grain loads. The gun does have a curved metal buttplate, so the recoil-sensitive shooter could easily add something there to cushion recoil if necessary.

The gun is built robustly enough that it should handle just about any .357 magnum load out there without excess wear, and of course you can shoot .38 specials if you’re looking at reduced power needs or want to save a little coin at the range.

Conclusion

The Uberti website no longer lists the Lightning as available for sale, so if you’re interested in one of these guns you’ll need to hunt for it on your favorite firearms auction/sale site. The MSRP was $1259 last I saw.

So, if like me you’ve been thinking that you need to get a .357 lever gun, broaden your horizons a bit and consider the Uberti Lightning pump, instead. I am.

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And about a year ago, I found one. Well, kinda.

What I found was a Taurus Thunderbolt:

That’s a 26″ barrel, and the tube mag holds 14 rounds of .357 mag (I think it’ll hold 15 of .38 special, but I would have to double-check that). Stainless steel, with walnut stock and fore-grip. The MSRP was $705, and I got mine (new, unfired, but it had been a display model for Taurus, so it had been factory reconditioned) for about 2/3 that price. You can still find them on various auction/sales sites for about $600 and up.

The Taurus isn’t as nice as the Uberti was, in terms of the finish. Still, it’s quite nice enough, and the mechanical aspects all seem to be fine. Particularly after breaking it in (say 3-400 rounds), there’s much less tendency for the design flaw mentioned above to trip you up, and most of the people who have shot mine have gotten the hang of it quite quickly.

It really is a slick-shooting gun, and once you’re used to it you can fire the thing almost as fast as a semi-auto carbine. It’s also easy to keep the gun shouldered and on-target, which I find difficult to do with a lever-action gun. I’ve found the gun to be quite accurate, easily as good as the Uberti version.

Being able to ‘top off’ the tube mag is nice, and there’s no need to fuss with magazines — though reloading it is definitely slower, and an acquired skill. Also, you have to carry loose rounds in a pouch or pocket.

My Thunderbolt weighs more than the Lightning (8+ pounds compared to less than 6 for the Lightning), due to the 6″ longer barrel/magazine. That makes recoil even more manageable, and I haven’t had anyone complain about shooting it even with hot .357 magnum loads. With mild .38 special loads it’s like shooting a .22, and a lot of fun for plinking.

I’m really happy I found this gun, and again I find myself saying what I did in my original review six years ago: if you’re in the market for a lever-gun in .357 mag, consider opting for a pump version, instead. And definitely, if you get a chance to shoot either of these guns, take it. You’ll be glad you did.

 

Jim Downey

 

January 14, 2018 Posted by | .357 Magnum, .38 Special, .45 Colt | , , , , , , , , , , , , , , , , , , , , | Leave a comment

Pump it up.

Last weekend I had the chance to revisit a couple of old friends, and try out something new: pump rifles. These guys:

PumpsFrom top to bottom:

 

If you check those links, you’ll see that I have written formal reviews for both the Uberti and the USFA previously. So I won’t spend much time talking about them.

But the little Taurus deserves a quick review. Because I found it to be a *very* nice little pump gun. The action was slick and didn’t have any problems, even though it was basically brand new. The Buckhorn sights are classic for a reason: they’re intuitive and work very well at modest distances. And even though the gun is relatively lightweight (compare the neck of the stock to the other two pump rifles above), there’s more than enough mass there to tame the recoil from the .22magnum cartridge. That means that you can get very quick and tight groups out of it even just standing and shooting it unsupported. Shooting it is just a blast, though one which doesn’t come with a lot of muzzle flash.

And the wood & finish on this gun is surprisingly good:

Taurus pump

 

I also want to share a couple of detail pics of the engraving on the USFA:

Engraving

And the other side:

Engraving2

Very nice!

I *do* like pump guns.

 

Jim Downey

 

November 22, 2014 Posted by | .22WMR, .357 Magnum, .38 Special, .45 Colt | , , , , , , , , , , , , , , , | Leave a comment