Modular Driven Technologies is a Canadian based company that has been making rifle accessories for some time now. In the past we have reviewed the LSS chassis and the HS3. After reviewing those systems, we received several requests to review the TAC21. The MDT TAC21 Chassis predates the LSS and HS3. It seems to sit at the opposite end of the design spectrum. All three chassis use AR type stocks and grips. The LSS and HS3 take an almost minimalist approach to chassis design. The TAC21 is a behemoth in comparison.

The chassis is available for Remington, Savage and Tikka rifles. MDT sent us the Remington 700 Short Action version. The TAC21 takes a “tube gun” style approach. The barreled action is completely enclosed in the chassis. This makes installation a little more difficult than on your average chassis. The trigger assembly must be removed from the receiver so that the action can be slid into the chassis. Removing the trigger from a Remington is a fairly simple task. However, re-pinning the trigger with the bolt catch inside the chassis is a bit of a chore.

After installing the action and trigger, the rest of the assembly is fairly straight forward. The recoil lug recess is a very open design and will accept a fairly thick lug. The forend slides over the recoil lug area and secures with three screws. This design prevents the use of a recoil lug that is taller than the factory Remington 700 lug.

The TAC21 chassis accepts any standard AR15 buttstock. We chose to install the MDT Skeleton Stock, however a Magpul PRS or even a standard A2 stock will work. The MDT Skeleton Stock is fully adjustable and a lighter weight alternative to the PRS. The Skeleton Stock does have a higher comb than the PRS. This needs to be accounted for when choosing the appropriate scope mount. We found that the 1.5″ Spuhr ISMS (SP-4002) was too short. This mount has worked well for us on other chassis systems and AR rifles.

The TAC21 Chassis will accept any AR15 pistol grip. We chose to use a Magpul MOE+ grip. The “duckbill” placed my hand in just the rifle position for a flat trigger finger.

The forend on the TAC21 is drilled and tapped to accept picatinny rail sections. MDT offers a variety of rails. We chose a flush-cup equipped rail to make sling attachment easier. The TAC21 will also accept Magpul polymer rails.

Modular Driven Technologies was nice enough to send along a couple of their new polymer magazines. These worked well in the TAC21, but may be too tight in some other chassis systems. The TAC21 will also accept standard AICS Pattern magazines. Steel Accuracy International five and ten round AICS mags worked well.

While working with the TAC21, we only found a couple drawbacks. In order to remove the bolt, you have to un-latch and remove the buttstock. This is fine in an administrative environment. If you have to remove the bolt to clear a malfunction on the firing line, it can cost time. The buttstock removal does allow for more compact storage. We found that in many cases, we could leave the suppressor attached and pull the buttstock in order to reduce the possibility of zero-shift.

Another drawback we encountered was the design of the safety-selector cutout. In order to manipulate the safety, you may have to reach into the cutout and “pick” the lever into position with the tips of your fingers. This is not difficult with a factory Remington trigger, but on the Xtreme Mod-22 trigger, it takes considerable fiddling to be able to get it into “safe” position.

The TAC21 is not a lightweight chassis. The chassis itself weights between 3-3.6 Lbs. depending on which model you choose. You still have to add a buttstock and grip to the final weight. This is not a setup I would choose for a hunting rifle. However, some users may prefer the weight. If you are running a heavy caliber rifle, the weight adds some recoil dampening. This CNC machined chunk of 6061 aluminum is solid and does have a high quality feel to it.

Overall, the TAC21 is a quality setup. If you can accept the weight and the minor drawbacks, it is a good option to give your bolt action rifle AR type ergonomics. With a price starting at $689.99 the price is competitive with other chassis systems of this type.