Quote Originally Posted by BoilerUp View Post
Now that I have an MPX I'm looking more closely at the MCX. I'm impressed by the design although I'm generally a mil-spec DI guy. I didn't mind venturing further afield on the 9mm platform as I never seriously consider 9mm ARs anyway (would have gone with an MP5).

I don't know any other company that is investing/risking as much in R&D for the civilian consumer as Sig and the innovation is showing. They've had some issues along the way (gen 1 / 2 w/ MPX), but I'd rather them continue to learn and risk obsoleting themselves then abandoning all development once it's out the door (which we've seen several times from other manufacturers).

It will be a while until I have budget to seriously consider picking up an MCX, but I definitely understand the attraction now.
So, here we are 7 years later with the SPEAR LT, the 3rd generation of the MCX. The SPEAR LT addressed the main thing that was holding me back from the MCX: fully ambidextrous controls. So with the looming WA AWB I finally jumped in with the 11.5 5.56 pistol, immediately dropped my Form 1, and also purchased the 300 AAC conversion parts. While I do want to get one of Sig's new suppressors, I decided to run the SF RC2 for now. Sig lore hit home and I could NOT get the Muzzle Device off the barrel so sent the barrel back to Sig. They sent me a new barrel so apparently even they had a hard time removing the flash hider! I've added an EXPS3, Arisaka light set-up, KAC BUIS, and Surefire closed tine flash hider / SOCOM mount. Decided on the SL-M stock which is new for me. I'm usually a SOPMOD stock guy, but those are too wide to sit close to the receiver when folded. The SL-M seems like a good compromise. Also added the Tango Down vertical grip, which reminded me of why I hate the M-LOK system (yes, it looks better than Keymod, but actually using Keymod is much easier IMO). I'm also using Magpul M-LOK panels for the first time. I like them, but the geometry of the SPEAR LT handguard makes them not want to sit flush one the 3/6 o'clock sections once you get aft the cutout for the M-LOK sections at the 1:30 / 10:30 positions, so am using a narrower BCM panel section on the right side.



I finally started running some drills with it yesterday to get a feel for it. Initial impressions are very positive. Super smooth and light recoil. I was hoping for this, as I believe the MPX is smoother than even MP5s, which are sweet, so my initial reaction is the SPEAR LT gives you roller-lock level smoothness in the M4 platform - which is awesome. The stock trigger on the SPEAR LT is also quite good. The Geissele Super Tricon is my go-to, so I generally prefer two-stage triggers. Sig's trigger is a two stage with similar pull weight to the SSA (4 to 5ish lbs, I'm guessing), is pretty smooth, breaks cleanly and has a good reset. While not as good as a Geissele, I don't feel the need to replace it. Sig has also improved the ambi charging handle at least over the stock version that came on my MPX that I eventually replaced with a Raptor, but I don't feel an urgent need to replace the CH on the SPEAR LT.

Now for the bad news - I realized pretty quickly that my MD must not be concentric as accuracy when shooting suppressed was just horrible. No damage to the suppressor, thankfully, but I must have gotten a light baffle strike or nick as i had keyholes on paper. Luckily I figured this out after just a few rounds. The challenge here is Sig uses a taper at the end of the barrel instead of a 90 degree shoulder like everyone else in the world, so you end up needing a taper adapter if you want to use someone else's muzzle device. I used the Sig taper cap, but I'm sure it ended up not going on perfectly concentric. So, I need to re-install the MD and I'll use this as the excuse to finally get the bore alignment rod(s) that I should have always been using anyway. A little internet research quickly showed that I'm not the first one to have similar issues, so for those that make the jump over to the MCX just be aware and cautious when using any thing on the muzzle that isn't Sig's taper system.

I know there are some concerns out there regarding the rigidity of the handguard, especially for the 16" versions, but I'm not currently concerned about that given my SBR setup.

Overall, though, I think Sig has a real winner with the SPEAR LT and suspect this will end up becoming the first thing I reach for when heading to the range.