SIG MCX review

[HeavyDuty]

I've had 2 range sessions where I had my Romeo 4T on my MCX 300 zeroed and my first string of fire was about 4" low and left at 100 yards. The mount was tight so I rezeroed and continued to march. I thought maybe the sight was f'ed up but I didn't really want to send it back to Sig. I finally got a Wheeler FAT wrench and just checked the barrel bolts and neither was close to 60 in-lb. Hopefully that was the reason for the shift. When it stops raining I'll go to the range and see what it looks like.

I’ll check my Rattler - thanks for the heads-up!

Tightening the bolts made a couple clicks difference. I got it zeroed again with 150 grain Ammo Inc FMJ and all was good. I finished up with a couple mags of 108 grain frangible and 125 grain PPU hp and POI was about 3" high. Muzzle velocity of the 150 is about 1850 fps and the lighter loads are close to 2200, so I guess that makes sense. Still minute of badguy, I just need to be conscious of what I've got in my mags.

I’m glad I checked. Both were well short of even 40 in-lb.

[DMCutter]

Damn. Sig is gonna get us kilt in da streets. Interested to know what effect on your zero tightening them will have.

[JCN]

Virtus upper arrived so I can put it on the rattler lower.

[JCN]

The shooter in the Buffalo killings was wearing body armor.

“The gunman shot four people outside the store, three fatally, said Buffalo Police Commissioner Joseph Gramaglia. Inside the store, security guard Aaron Salter, a retired Buffalo police officer, fired multiple shots. A bullet hit the gunman's bulletproof armor but had no effect, Gramaglia said.

The gunman then killed the guard, the commissioner said, then stalked through the store shooting other victims.”

If I’m going to have a long-ish gun, I want it to be able to do long gun things.

[JCN]

I’m channeling my inner @HCM

If I’m going to go small, go small.

MI handguard and Vulcan ACSS optic.

Muzzle brake threaded for Rugged Razor.

[Corse]

The shooter in the Buffalo killings was wearing body armor.

“The gunman shot four people outside the store, three fatally, said Buffalo Police Commissioner Joseph Gramaglia. Inside the store, security guard Aaron Salter, a retired Buffalo police officer, fired multiple shots. A bullet hit the gunman's bulletproof armor but had no effect, Gramaglia said.

The gunman then killed the guard, the commissioner said, then stalked through the store shooting other victims.”

If I’m going to have a long-ish gun, I want it to be able to do long gun things.

If it’s plates no luck anyway. If it’s soft armor, supersonic 300 blk should punch through it no problem. The biggest issue would be actually having the MCX available in the first place. You’d probably be working with a 9mm most likely.

[JCN]

If it’s plates no luck anyway. If it’s soft armor, supersonic 300 blk should punch through it no problem.

False.



Supersonic Barnes TTSX does NOT penetrate IIIA.

The Rattler barrel is just too short and too slow with standard conventional 300 supers.

In the supermarket shooting, there wouldn’t have been time to deploy an MCX.

But if you did have a Rattler with supers, you might be sorely disappointed when encountering IIIA.

[Corse]

False.



Supersonic Barnes TTSX does NOT penetrate IIIA.

The Rattler barrel is just too short and too slow with standard conventional 300 supers.

In the supermarket shooting, there wouldn’t have been time to deploy an MCX.

But if you did have a Rattler with supers, you might be sorely disappointed when encountering IIIA.

Interesting. Is this the 110 or 120 gr? Do you know the velocity?

I’ve chronographed the 110s at over 2000 FPS from the rattler. They were definitely on the hot side though.

[Wondering Beard]

False.



Supersonic Barnes TTSX does NOT penetrate IIIA.

The Rattler barrel is just too short and too slow with standard conventional 300 supers.

In the supermarket shooting, there wouldn’t have been time to deploy an MCX.

But if you did have a Rattler with supers, you might be sorely disappointed when encountering IIIA.

That load has, as I understand it, a polymer tip which, at least theoretically, would bend when encountering armor thus limiting its capability to penetrate.

I hope someone who knows those loads well would confirm, and I wonder if other loads, without such a tip, would actually penetrate.

[WobblyPossum]

False.



Supersonic Barnes TTSX does NOT penetrate IIIA.

The Rattler barrel is just too short and too slow with standard conventional 300 supers.

In the supermarket shooting, there wouldn’t have been time to deploy an MCX.

But if you did have a Rattler with supers, you might be sorely disappointed when encountering IIIA.

That’s really interesting. I’d love to see more testing. My understanding is that the TTSX is the go-to supersonic bullet for short-barreled .300 blk. It’s surprising to see it can’t reliably penetrate soft armor. I wonder if this is the case for all supersonic .300 blk that isn’t specifically marketed as armor piercing, when fired from such a short barrel, or if this is specific to the TTSX. I’d be curious how some of the newer solid-copper stuff would do. If supersonic .300 blk out of a short barrel does generally have a tough time with soft armor, what are the advantages of supersonic over subsonic ammunition in something like a Rattler?