Get Ready for the .20-Caliber
This new cartridge may be the ultimate varmint round.
By Jim Carmichel - OutDoor LifeOh, no! Not another new caliber. Don't we have enough already? Well, maybe not. In recent times gun and ammo makers have kept gun writers dancing and readers dizzy with an unprecedented outpouring of new cartridges. Of course, any new cartridge is juicy grist for the gun writer's mill, but let's face it, we've milked that old cow until there's not much cream left. Just count the new .30-caliber rounds introduced in the past few years and you'll run out of fingers. And then there are all the 7mm's, .33s, .375s and .416s being endlessly reborn in cartridge cases that are stretched, shrunk, fattened, and liposuctioned. Still, there remain only a handful of basic calibers.
There are a couple of reasons why truly new calibers come along so rarely. One is that gunmakers are as slow as a cat eating a grindstone when it comes to developing new bore sizes. The other is that we, the shooting public, are thoroughgoing Puritans about our calibers and tend to burn new ideas at the stake. But sometimes a completely new caliber offers such exciting possibilities that it can't be ignored. So get readyhere comes the .20!
Why the .20?
Okay, your first question is: "What is the .20 for?" And next: "What does it do that existing calibers don't?" Primarily the .20 is a varmint caliber, and what it does better than other calibers can be answered by comparing the best and worst features of calibers on either side of it: the .17 and .22 centerfires. Probably the most attractive feature of the .17 Remington and the various .17-caliber wildcat variations is that they are a delight to shoot. Recoil is so nearly nonexistent that if it were not for the mild muzzle blast you'd think you were pulling the trigger on an empty chamber. Since the rifle remains motionless, you see all the action through the scope, whether it's holes appearing in a target, a coyote doing a nosedive or a prairie dog losing a grip on his parts. On the negative side, the .17 tends to be finicky about its ammo. Bore-fouling and subsequent loss of accuracy are ongoing problems with some rifles, and the little bullets are slaves to a wayward wind. Despite its 4040 feet per second (fps) muzzle velocity, the .17 Remington bullet gets carried nearly 8 inches sideways at 300 yards by a gentle 5 mph puff of crosswind. By comparison, a factory-loaded .22/250 bullet weighing 55 grains and pushed out the muzzle at only 3680 fps is nudged a tad over 5 inches by the same crosswind. That three-inch difference is vital to varmint shooters because it's about the chest span of a standing prairie dog.
The various .22-caliber centerfires, most notably the .22/250 Rem. and .220 Swift, which are usually loaded with 50- or 55-grain bullets, are less sensitive to the wind. However, in launching these bullets at velocities of 3600 fps and faster, there is a considerable amount of rifle movementnot hard recoil, of course, but enough to jump the scope so you can't enjoy the action. A few years ago I was determined to have a .22/250 heavy enough to lie still on a rest when fired and ended up with a pudgy 15-pounder.
When you total up the good features of .17s and .22s, and toss out the bad, you come to the conclusion that a bullet of some 33 to 36 grains of weight, moving at 3800 fps, or faster, would be about perfect. But a bullet in that weight range would be too heavy for a .17 and too light for a .22, meaning that a bore size about midway between the twoa .20 caliber--is, like Baby Bear's bed in Goldilocks, just right!
So if the .20 is so logical, why hasn't it already become the darling of varmint shooters? Explaining why gun people fall in love with one cartridge and snub another is as fruitless as trying to catch a falling star. But the main reason the .20 has yet to win the fancy of shooters is because it hasn't been available. Actually, during the late 1960s, the .20 had 15 minutes of fame when Remington announced its 5mm rimfire. With a 38-grain bullet at 2100 fps, the Remington was a passable varmint round inside 200 yards and earned considerable respect among turkey hunters. The rifles weren't much, however, and unsolvable problems prompted Remington to drop them, along with 5mm ammo (which now, by the way, sells for about $50 per box, if you can find it).
A Star Is Born
Following Remington's ill-fated experience with the 5mm rimfire, the .20-caliber concept again faded into obscurity and likely would have remained there had the folks at Douglas Barrels not been once again bitten by the .20 bug.
A.L. .20 TNT Ballistics
33-grain Hornady T-Max bulletRange
(yd.)Velocity
(fps)Energy
(ft.-lb.)Trajectory
(in.)Wind Drift
(in.)*0 3950 1143 -1.5 0 50 3632 966 0.6 0.1 100 3336 816 2 0.6 150 3061 686 2.6 1.4 200 2802 575 2.3 2.6 250 2558 479 0.9 4.1 300 2326 396 -1.8 6.2 (* 5 mph crosswind) Gardner, the longtime head man at Douglas, had championed the .20 caliber and considered it too good to be allowed to die. This ideal was passed along to his son, Tim, now president of Douglas, who passed the fever on to me some four years ago when he called with the news that Douglas was again making .20-caliber barrels. Not only that, but Walt and Eunice Berger, of benchrest bullet fame, were making pretty little .20-caliber bullets.
"What case would you use if you were designing a .20 wildcat?" Tim asked. A menu of possibilities flashed through my brain like numbers in a slot machine, then came to a stop on the .223 Remington. The powder capacity would yield at least 3800 fps with 36-grain bullets. There are plenty of actions already adapted to the .223 case, which would make building a rifle simple. And cheap .223 brass is available by the bushel. All in all, it was a wildcatter's dream. "I'd go with the .223 case simply necked down to .20, with the shoulder angle and everything else left as is," I told him.
Already I was getting excited by the project because his call caught me when I was in the mood to mess with something new and different. "Tell you what," Tim went on, stoking my interest even more. "Send me an action and I'll fit a .20-caliber barrel to your chamber specs."
"I'll go you one better," I replied, in a fit of uncharacteristic generosity. "I'll send you two good actions. Barrel one for yourself and we'll compare notes." Even before I hung up the phone I had a name for my new wildcat: the .20 Tim & Jim.
The 24-inch, stainless steel, 1-in-12-inch-twist, heavy-sporter Douglas barrel Tim Gardner fitted to my M-700 Remington action fit nicely in a pretty laminated wood Fajen varmint stock I had laying around. And, after mounting a scope, the rig was ready to shoot, except for one little problem: No ammo. One of the exasperations of tinkering with an original wildcat is the total lack of basic peripheral support such as loading dies. They simply don't exist. You have to make your own, or have them made, which takes time and slows the development process. I was in a rush to try the .20 T&J, so while sizing dies were being made to neck .223 cases down to .20 caliber, I went the other way and used a homemade neck-expanding spud to open .17 Remington case necks up to .20 caliber. Admittedly this was a quick-and-dirty backdoor approach, as was the use of a Redding .223 Competition die for seating the cute little .20 Berger bullets, but the result was a batch of shootable ammo.
Brace for Action
Wildcats can be ornery critters (especially the smaller bores) so I tied a string to the trigger and backed off a prudent distance before firing what I calculated to be a hot proof load. The rifle barked smartly but remained in one solid piece, with the extracted case showing no signs of stress. So far so good, but what about accuracy? This is the true test for any new round, especially one intended primarily for hitting varmints at long distances, so I settled myself at the shooting bench with something like the apprehension a dad feels when his son has his first time at bat in a Little League game. Would it be a home run or a strikeout?
After bore sighting, the first shot hit paper not far from the aiming square. Next shot: close to the first but not touching. Third shot: closed the gap between the first two holes. Shots four and five: lost somewhere among the first three, rounding out a tidy little group. Pow! A home run!
If anything was disappointing about that first session with the .20 T&J, it was the utter lack of challenge. Part of the fun of wildcatting is nurturing a new round until it blooms. But with the .20 T&J there was no need to bring it to heel; the first half-dozen combinations of powder and load I tried all grouped with equal precision. Shot after shot, without even being cleaned, the gun just piled bullets on top of each other while the chronograph clicked out velocities from 3650 to 3960 fps, depending on the load being tested.
A couple of weeks later, when outdoor life Editor-in-Chief Todd Smith visited our test range, he duplicated the .20's early performance, with the little 36-grain Berger bullets all trying to crowd into one tiny hole. Clearly the .20 T&J was a winner and we made plans to publish the report you're reading now. But first I wanted to try the .20 T&J on real varmints, and prairie dog season was still two months away. Meanwhile I continued trying different load combinations and continued to be amazed by the .20's almost total lack of temperament. Like a big, woolly family dog that doesn't mind having its ears pulled, the .20 T&J seemed content with anything I fed it.
When developing a wildcat cartridge you can count on spending more money than it will return, even if it hits the big time and becomes a legitimate factory offering. However, it does your ego good to have your name connected to a successful cartridge, and I was feeling downright boastful about my development of the .20 T&J until I happened to pick up a shooting magazine and spotted an article about another .20 caliber. Before I was halfway through the piece I was having a good laugh at my arrogant pomposity for having thought my .20 T&J to be an original design. The author, a nice guy by the name of Todd Kindler, was describing a cartridge of his origin that was essentially identical to my .20 Tim & Jim, even to the name, which he called the .20 TNT, for Tim N Todd. Moreover, our loads and results were virtually the same and his conclusions mirrored minethat the .20 is a good idea whose time has come.
There's an unwritten rule that says whoever gets to print first with a new discovery or invention gets the credit, and I'm happy for Kindler to get full credit for his work with the .20 TNT, especially since he has been instrumental in getting to market such .20-caliber accessories as loading dies, bullets, cleaning rods and brushes. Reach him at The Woodchuck Den, 11220 Hilltop Road SW; Baltic, OH 43804; 330-897-0614 or www.smallcaliber.com.
The .20's debut in the prairie pup patch was spectacular. The gaggle of certified gun nuts I was shooting with all had to give it a try, and it was love at first trigger pull for Dave Kidd, a Montana rancher with whom I often hunt. Kidd, who has shot more prairie dogs with more rifles and calibers than anyone I know, was quick to realize the potential of the .20 and set about developing a version that would top 4000 fps. Called the .20 BR Express, Kidd's cartridge is based on the Remington BR case for a velocity yield of 4400 fps.
Hornady also has joined the .20- caliber parade with a 33-grain T-Max that's accurate and hits like a jigger of nitroglycerine, and Shilen is also making .20 barrels. It's just a matter of time until a factory .20 is announced. We can only guess which gunmaker will be first, but I have my suspicions, and I also believe the factory round will be similar, if not identical, to the .20 TNT, but we'll have to wait and see.
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