Tippman Arms M4-22 Redline Semiauto .22LR Rimfire AR-15: Review

Has the cost of ammo been giving you an attack of the vapors lately? It should. A range trip to do some AR-15 blasting used to cost $60 in ammo. Now it can easily be twice that. We used to joke about practicing until you were “knee-deep in brass” and now just the thought of it makes your credit card spontaneously combust. Loading your own is one stop-gap method to keep costs down, but with the scarcity of primers these days, it isn’t always a ready alternative. How about rimfire? Yes, I know that .22 LR is also hard to come by, but at least it is less expensive. Right now, the latest cost quotes I’ve been able to get on .223 ammo come down to $400 per thousand, while .22 LR runs about $150 a thousand rounds. So, that price differential of $250 per thousand rounds fired, is what gets us going on a rimfire AR-15.

So, let’s look at Tippmann Arms, specifically their Redline AR. The basic outline is that of an M4gery, a sixteen-inch barrel, in a free-float handguard, with folding iron sights, a flat-top upper, and a tele-stock on the buffer tube. Which is kind of like saying your favorite car is a vehicle with a wheel at each corner, doors, and a roof to keep the rain off of you. There are cars, and then there are cars. Ditto rifles.

M4-22 Redline

The Tippmann Redline is built on a flat-top AR-15 receiver set built up in collaboration with Tandemkross. The receiver set is aluminum, of course, because that’s what we expect and deserve. Plugged into the upper receiver is a 4150 steel barrel, chambered in .22 LR, and with an appropriate twist rate for the rimfire. One of the problems with the conversion kits of old was that the bore and twist were just wrong for the .22 LR. The old (the new is even worse) twist rate of 1-12 was too fast for the long rifle, which calls for a 1-16 twist. Combine that with the centerfire bore being a nominal .224", while the rimfire calls for a .221" (and bullets sized appropriately) and you often had a bore-leading mess. Not any more, with the Tippmann Redline. Oh, and the chamber? The conversion kits were a kludge of a .22 LR bolt design, with a faux .223 cartridge case ahead of it, leading to the rifled bore. So, your poor .22 LR 40-grain soft lead bullet had to slide down a smoothbore section of steel tube, nearly two inches of it, before the slug was even close to anything remotely called rifling. On the Redline, as with all proper .22 LR ARs these days, the barrel sits in the receiver with a proper .22 LR chamber at the back end.

Now, in a curious addition, the Redline adds a Tandemkross Game Changer Pro muzzle brake on the other end of the barrel. The need for a muzzle brake on a rimfire rifle is pretty limited, but hey, if it helps, it helps. And you can always take the brake off and install a suppressor, right? Yes, you can, because the muzzle is threaded the standard pitch; ½-28. Additionally, the barrel is fluted, and then given a red Duracoat finish. This is eye-catching and a good thing when you are introducing a new shooter to the fun that rimfires can provide.

The barrel is held inside a free-float handguard with MLok slots on it. The handguard is listed as being made of “composite” which to my touch means polymer, but the Redline is not something an airborne Ranger is going to train or fight with. This is a practice and new-shooter firearm, and shaving a bit of weight off of the total is a good thing here. Too heavy and your new shooter will not be having fun. The handguard does have a full-length top rail, at the level of the upper receiver, so your accessories mounting options on the Redline are the same here as they would be on a centerfire rifle. And if you just have to have your practice rimfire AR feel and handle the same as your centerfire one, well, you can swap handguards. The Redline handguard is held in place by a pair of cross-bolts, so remove those, slide the handguard off, and then deal with the barrel nut, if it needs to be dealt with. Since there are a hundred other handguards out there to be had, you will have to figure that part out yourself. Tippmann has done a good job here, if you want it changed, then you’ll have to change it.

The AR-15 is good that way, being very user-serviceable. The nine-inch handguard extends far enough forward that it would cover a gas block, were there one on the barrel. Since it is a blowback rimfire, no block, no gas tube, none of that. The upper receiver has a spring-loaded ejection port cover, and a working forward assist. Now, I view a forward assist as something that is properly used so rarely that it might as well not be there, but I have to applaud Tippmann for not only including one, but making it actually work. In the real word, if your rimfire rifle is so gunked up that you need to use the forward assist to get it to fully closed, you are long past the clean-by date on your firearm. Stop abusing it, and scrub it. Both sides of the port cover are red, so when the port is open, even if you don’t see the nickel-plated bolt, the red will catch your eye. Just to be even more eye-catching, Tippmann makes the safety lever, bolt hold-open, forward assist button and magazine button red, as well as the charging handle.

On the upper receiver and handguard, Tippmann installs a set of folding polymer BUIS. You can get a Redline with a Hawke Reflex sight already installed, and a “compliant” Redline, with a non-telescoping stock and no muzzle threads. (Those of you who have to do that, I weep for you.) The lower is your basic standard AR-15, with one interesting addition. Tippmann has used the Tandemkross hiveGrips pistol grip, with a soft synthetic surface, textured pattern, and red accents on it. I’m usually pretty blasé about pistol grips, and generally prefer less than more, and I find that this is a nice grip to be using. The controls on the lower are standard, with a two-position selector on the left side, for right-handed shooters, and a bolt hold-open lever on the left side as well. Yes, that’s right, the magazine, which we’ll get into in a bit, locks the action open after the last shot.

On the buffer tube, Tippmann has installed a basic M4 slider, since they know we are very likely to want to install something else. It has to have a stock, so they provide one, but it is as easy as any other to swap out the basic M4 for a different stock. At the base of the buffer tube, Tippmann has installed an ambidextrous sling plate, in case you want to install a single-point sling. Me, no, but if you do, it is there. Inside the Redline is where all the very interesting details are lurking. Well, interesting for a gunsmith like me. First of all, the Redline uses standard fire control parts. Nothing proprietary to accommodate some funky rimfire goings-ons here. So, you have the expected mil-spec-contour-and-function parts inside, and should you, at some future time wish to upgrade the trigger, you can do that. The lower is built to accept standard AR-15 lower parts, which means you can install some high-zoot trigger system, should you feel the need. In other words, you can start with a basic “let’s get the nieces and nephews hooked on shooting” and later build it into a target-competition training tool. Hats off to Tippmann for that, too.

Rimfire BCGs

Now, for the bolt/carrier group. Once again, we refer to the traditional conversion kits. There, the space occupied by the .223 bolt and carrier has on the conversion the entire upper receiver parts. The action spring or springs are part of that assembly, and they do not need to centerfire buffer and spring for anything but positioning. On a conversion in your .223 AR, the buffer and spring are there only to keep the rimfire assembly from sliding back into the buffer tube. Well, Tippmann doesn’t do it that way. The rimfire bolt is the length of a centerfire bolt and carrier, almost. (The barrel, sticking back into the upper receiver, takes up an inch or so of that length) Tippmann uses a polymer buffer, and a spring appropriate to the “oomph” of a rimfire, to provide a system that functions in the say way as your centerfire. It does not cycle to the same length as the centerfire one, both because it doesn’t need to, and because if it had that much of a running start, it would probably break the bolt hold-open in short order. As a result, when you take the Redline apart for cleaning, you’ll notice that the charging handle is much shorter than one in a centerfire rifle. The bolt, nickel-plated and with a regular rimfire-type extractor, has centerfire extras. There’s the dished section on the side, where the ejection port cover spring assembly sits. And there are notches for the forward assist.

Now for the magazines. When I first saw the magazines, I thought (And said, at the SHOT Show) “You couldn’t just use the standard .22 magazines that we all have buckets of?” Well, no. Because, as the owner and designer of Tippmann Arms, Denny Tippmann, Jr. said “I had a few ideas.” Now, making a .22 LR firearm feed reliably is not new, but it isn’t easy. The big rim, the short length, the low power, all conspire against any of the usual methods. One traditional method is a tube, under the barrel. Well, that’s out for an AR-15. Ruger, with their rotary magazine, has a design that works, but just mentally trying to design a fit of that into an AR-15 gives me headaches. So, a curved, single-stack design is common. Well, Denny took that curved, thin design and put it inside of a sliding shell. Slide the shell down, and you can then grab the sides of the magazine follower, slide it down as you load, and not have to use the round you are loading to depress the stack.

When you slide the cover back up, it not only becomes the same profile and size as a centerfire magazine (so your mag pouch or belt holders all work just fine) but it comes up to offer additional protection to the feed lips. The usual rimfire magazine has a skinny feed lip stack protruding above the main body of the magazine. This was probably done to accommodate the conversion setup and the bolt design they had. Denny made the bolt fit the magazine, and protected the magazine feed lips. Magazines come in 10-, 15-, and 25-round capacities. Now, this is an improvement over other designs, but it does mean that you are locked into Tippmann magazines for your Tippmann Arms rimfire. The good news is that Tippmann offers extra magazines, and they cost pretty much the same as other designs. Look on the bright side; if your magazines won’t fit other shooters rimfire ARs, then they won’t be tempted to borrow mags from you.

Clever and interesting designs, and bright colors are all well and good, but we’re interested in how firearms perform. To that end I dug into the rimfire shelf to see what, if any, .22 LR I had, and managed to come up with enough to do some thorough testing. OK, first, and to the great surprise of exactly no-one, the felt recoil in a .22 LR rifle that weighs a bit over five pounds is...nothing. I didn’t remove the muzzle brake to see what contribution it might be making to the recoil because, well, why? The trigger setup is entirely GI in design, and it worked as you’d expect; it never failed, and the trigger pull, while heavy, was clean enough. If I really felt the need, I could yank all the internals out and plug in a Wilson packet trigger, a LaRue or a Geissele firing parts set, and get a match trigger. Now, if I was using this as a new shooter introduction rifle, I’d leave the trigger alone. If I was using the Redline as a training setup for a 3-Gun rifle, I’d put the same trigger in the Redline as in my competition rifle.

Rimfire Fun

The magazines are easy to load. Press the sleeve button in and slide the external shell down. Now you can grab the follower and slide it down as you load rounds, without having to use each round as the lever to compress the follower. Once loaded, slide the cover up until it locks in place by means of the button. The Redline uses a much-modified bolt hold-open lever, to work with the rimfire magazines, so your lower is not going to be convertible to a centerfire rifle, at least not without a bunch of work. (That’s not why you bought it, is it?) When you fire the last shot, the magazine locks the bolt open. Swap magazines, and you can either press the bolt hold-open lever, or use the charging handle. Oh, and that’s a detail we need to keep in mind. The bolt on the Redline does not travel as far back as the bolt/carrier group on a centerfire AR-15. The charging handle thus does not travel as far back to charge the rifle. You may, the first few times, find yourself trying to pull the charging handle the full distance, only to have it stop abruptly, and have your hand come off. The bolt will then go forward and chamber a round. It takes a few iterations to get used to it, then everything is fine.

Accuracy was everything I expected. Rimfire firearms can be very touchy about what they like and do not like. It is worth the effort to find out what your Redline will like, and as much as possible, fed it that. Disassembly is the same as it would be on a centerfire AR-15, but it can be a bit exacting. The bolt is not as self-aligning as the bolt/carrier assembly on a centerfire. And the short charging handle does not ride in the groove of the upper receiver. In the Redline it simply hooks into the slot for it cut in the bolt. So, you will probably find that reassembly is easier if you just set the upper down on your bench, and use both hands to insert, align, and press forward the upper receiver internals. Again, a few iterations of it and you’ll learn the feel.

In this day and age of ammo shortages, having a lower-cost practice rifle is a good thing. The price of the Tippmann Arms M4-22 Redline, at $720, means that given the current price differential between rimfire and centerfire, you will have recouped your investment in the Redline at just under three thousand rounds of .22 LR. After that, you are saving money. “Three thousand rounds/ that’s a lot of ammo!” Really? If you go to the gun club and shoot off 200 rounds of .22 LR (easily done in an afternoon) and do that twice a month, you will not only be a far better shooter than you were when you started, but you’ll have paid off the Redline in seven months. If you want to get better, you have to do something beside wish for it. The Redline lets you get there faster and at much less cost than otherwise.

Tippmann Arms M4-22 Redline AR-15 Specs

• Type: Hammer-fired, semiautomatic
• Caliber: .22LR
• Capacity: 25+1 rds. 
• Barrel: 16 in. 
• Overall Length: 34.5 in. 
• Weight: 5 lbs., 4 oz. 
• Finish: Black oxide steel, polymer, anodized aluminum
• Grips: Custom AR grip
• Sights: Aperture rear, post front
• Trigger: 4.6 lbs.
• MSRP: $720
• Manufacturer: Tippmann Arms

---

About the Author

Patrick Sweeney is a life-long shooter, with more than half a century of trigger time, four decades of reloading, 25 years of competition (4 IPSC World Shoots, 50 USPSA Nationals, 500+ club matches, and 18 Pin Shoots, as well as Masters, Steel Challenge and Handgunner Shootoff entries). He spent two decades as a professional gunsmith, and two decades as the President of his gun club. A State-Certified law Enforcement Firearms Instructor, he is also a Court-recognized Expert Witness. 

---

If you have any thoughts or comments on this article, we’d love to hear them. Email us at FirearmsNews@Outdoorsg.com.