The new SLiM (Slim Lightweight Modular) handguards are indeed pretty darn light. DD doesn't call out any specs on the new handguard, but comparing the new 6.28 pound DDM4 V11 rifle to the the 6.54 pound V7 we can see the 15" SLiM handguard is a four ounces lighter than the shorter, 12" MFR (Modular Float Rail) handguard. This is for the government profile barrel, the V11 LW is 6.15 pounds, which is two ounces lighter than the 6.29 pound V7 LW.
Wizardry? Perhaps. More likely, the SLiM doesn't use the same steel inserts around the barrel nut that the MFR has. more
Does the introduction of the oxagonal SLiM signal DD's intention to discontinue the sweet roundness of the MFR? Daniel Defense never cranked out more than a few MFR accessories and all were simple Picatinny rail sections. The MFR's slotted attachment system works well, but why continue to support a proprietary system when there is a burgeoning cast of companies already pumping out direct attach KeyMod mounts for lights, grips, sights, slings and covers?
The MFR is likely less expensive to manufacture than the SLiM since it needs less machine time. But, the simpler tube construction is probably offset by the multipart barrel nut and it's complicated installation that requires the adjustment of a bunch of tiny set screws to square the handguard up to the barrel/upper receiver.
The SLiM uses DD's three part Bolt-Up mounting system which is pretty painless to install. A backer plate goes on first, followed by the barrel nut. The handguard slides over the barrel nut and bolts to the backing plate, sandwiching the barrel nut and squaring up automatically on the barrel nut's shoulder. (Tip: have a set of ball-end Allen wrenches handy if you're going to work on any of DD's Bolt-Up handguards.)
Heck, maybe we'll find out the MFR is significantly stronger or more rigid than the SLiM and DD will offer them both to suit different customers. Failing that, I'm guessing this release marks the beginning of the end of the MFR.
At the moment, the SLiM is only available on DDM4 builds. We should see them released as an accessory sometime in Q3/Q4 2014. The DDM4 V11, V11 LW and V11 S2W are each $1599.
