First Look: SIG Sauer MCX-SPEAR 6.8X51

1. Nice to have the XM7 available in the caliber it’s meant to use. But ouch, will need a conversion kit if it’s $80 for 20rds, even half of that would be a lot if you intend to actually shoot it. Hopefully other ammo brands will step in if this round is going to be used long term.

   • Very interested in seeing how reloading will work out with the case involved….. also seeing how close to the crazy pressure the testing suggested was necessary for velocity in the bid requirements.

     • The military load uses a steel reinforcement at the base the civilian version lacks. At a guess, they are using a lot of fast burning powder to get the crazy pressure level.

       • Ah so we will only see the gimp round.

         • Load your own. Seriously.

           • If I was a more paranoid and distrustful of the government sort I would suspect that the civilian available components and firearms would be subtly different that would prevent getting things to the same level. I do not think they have the ability to do that for the most part but I am highly suspicious of the lack of 855A1 and m80A1 on the commercial market still.

           • MidwayUSA and BattleHawk Armory currently list what appears to be the military round. Hybrid case, 113 gr solid at 3200 fps, 460 round ammo can. 12-13 hondo. Get it while supplies last.

             • Honestly surprised but agree with that last line if anyone is at all interested in such a rifle.

         • Maybe. The SAAMI (civilian) standard allows the same max PSI of the military loading. Whether ammo manufacturers will sell it that way is an open question.

           But that explains the lack of guns chambered for it. They have to be able to handle the full power loading, because that’s the standard.

2. I might jump on the bandwagon in 20 years or so when either the price has come down or inflation catches up.

3. Well, the military decided that the 5.56 doesn’t cut it. Again. So they come up with a new caliber. Again. (A new rifle too. I thought the AR platform was the pinnacle of rifle design.) I’d like to know, exactly, what this caliber does that the 7.62X51 doesn’t already do. I don’t mean on paper. I mean in the real world.

   • Body armor penetration?

     The round looks like a short-cased .270 with much higher pressure.

   • Nothing…sir.

   • 1. Joe Average citizen won’t be able to utilize CONUS “battlefield” pickups.
     2. Lake City Arsenal is already downsizing production line for 5.56mm

4. Southern, how many people have you shot at that were wearing body armor?

   • More a modern thing, Iraq/Afghanistan saw a few cases of steel armor and the 855a1 was good enough in handling that. The Chinese ceramic plates that are showing up in Africa and other areas not so much and those have stood up to everything but tungsten cores so improvements are needed somewhere. Few criminals will bother with rifle armor but it does come up now and again in raids so who knows.

5. I thought this civi version was supposed to be available like a year ago. I guess it’s like the Sig piston AR that I waited two or three years for to show up on the mkt after they announced it was for sale. In the software industry its called vaporware.

6. With the .308/7.62×51 version having a MSRP being around $6,000 I’d guess this caliber will probably be similarly priced.

   I did get a chance to put a few rounds down range with the .308 version back in June. Pretty easy to clang steel at 100 yards shooting offhand with it. Nice gun but definitely out of my price range.

7. The good, gas piston driven, side non-reciprocating charging handle. Side folding stock.
   The bad, that dumb rear charging handle.’
   The questionable, the round. Might be great for those in the military facing off against enemies using body armor. Not seeing a whole lot Chicago gang bangers running around with body armor.
   Also questionable is availabilitity of brass and price of factory ammo.
   I think I could get a FN SCAR in .308win cheaper and just as good. Magazines are cheaper too.

   • Armor more shows up with cartel, gun runners and large volume trafficking (drug human whatever) up my way. Haven’t heard of it being used yet but kevlar and Chinese Militech(functional lower quality lv 4/rf3) plates have been recovered. With that said you are probably doing some shit if you need to consider AP above pistol level.

     • The SCAR is a pound lighter and $2k less expensive. And it’s proven. Those things matter. Is there no 7.62 NATO round that will penetrate the same armor?

       • M993 sometimes at closer range otherwise you are going into rare/exotic loadings RUAG swiss p or high explosives for a core. With that said no guarantees this will be better except for potential velocity boost.

       • Pending moderation but short answer sorta but not in meaningful numbers.

       • Something is not liking my replies today so yes there are a few options but not in any meaningful numbers or ability to produce and/or store in mass like hardened steel carbide cores so functionally nonexistent for all but small unit use.

     • Or you just live near the Mexican border?

       • That border has been getting bigger in the area it covers lately.

8. So the 277 sig is the cartridge that modern body armor built – and even better modern body armor will make it obsolete in a couple of weeks.

   Got it.

   I am wondering if the opposition is following suit and adopting hotter ammo, or if maybe they have decided that body armor and modern materials will inevitably win the race – rifles being limited by weight and recoil.

   Like I need to know. Which reminds me, where’s my free robot?

   • Lugging around an extra pound of rifle matters. I think I’d make do with a SCAR, but maybe I’m missing something? A giant military contract perhaps?

   • Armor runs into issues as well re weight thickness mobility and cost. I am guessing there will be an equilibrium point where the most cost effective option that is good enough will become the default to beat/defend against. Then we will see a focus on portable guided high explosives for when peer conflict comes into play and use the rifles for putting down irregulars/insurgents/civilians where even modest armor can be an overwhelming advantage in attrition like what we saw in GWOT.

     • I have seen data for 300 Wthrby that says Reloader 19 will propel a 110 gr 30 cal bullet to 3600-3700 fps.

       Just a guess, that would do…

       Pressures are high, but not “crazy”. Big ass cartridge tho.

       • Bullet would frag out before going through the ceramic portion of the plate let alone the backing, unless it was a copper solid in which case a few hundred fps would be shaved off the velocity (more bullet volume than lead core for same weight)…..which might do it for the Chinese plates but we were never able to get anything from a 300 winmag through level 4 and apparently even m2ap pulls from the 30-06 and reloaded in various 30 cal magnums have trouble. With that said how well are various full size magnums going to do in combat where suppressive fire is common?

9. 277 Fury is not the same round as 6.8×51.
   TTAG is advertising a military cartridge only.

   • SAAMI would disagree with you.

10. Mix half an antiquated AR with half an antiquated AK and call it new.

11. If I see someone I suspect of wearing body armor I am shooting MOG or Minute of Groin. We get to that point where I live things have gone really bad.

12. I’ll take a serious look at the 10” barreled version if it gets released.

13. The entire SPEAR Thang is a monumental waste of Taxpayer’s Money…..someone should inform the military that We Are Broke.

    US Federal Debt + Federal Unfunded Obligations = $140,000 for every Man, Woman & Child in the Nation.

    90% of Americans cannot even pay the interest on that debt, much less the principle.

    That weapon will not make a material difference in any combat situation from weaponry our military already possesses. And, what’s going to happen when the plastic cases disintegrate due to some completely unforeseen flaw, like Honda’s plastic fuel pump impellers or plastic steering gears.

    • The cases aren’t plastic, they’re steel and brass, and much heavier than 5.56.
      The cases have to be steal at the rear to handle the extremely high pressures rounds.
      The rifle is also several pounds heavier than the M4, again due to the extremely high pressure round it fires.

    • I remember many similar arguments against body armor from 20 years ago. Ended up needing to revamp how we taught combat medicine as we had a lot fewer fatal chest wounds and way more generally deadly wounds to the extremities that might be treatable with quick attention. Why should we allow potential enemies the same advantage? This is of course assuming the capability of bypassing lv 4/rf3 plates at useful distances is an option for some of the loadings they are looking to use and if not probably a waste but a lot of military spending is like that.

      • Wounding location stats haven’t changed that much since at least VN.

14. Funny. We complain about weight, then field a rifle a pound heavier than the FN SCAR. Then we add body armor to our troops to the point they are dependent on APCs. No more field humping it. Especially if you had to hump it with a full load out ruck and body armor. Seems we are defining ourselves in warfare that someone could exploit.

    • We do have a habit of switching out doctrines once shit gets real. But we also used to be a lot more merit and fitness oriented for leadership so we will see how things play out with the next few years.

15. Seems we have got slow at adapting to new doctrines. Seems our current leaders in the military are more concerned with DEI stuff than real leadership.

16. Remember when everyone was claiming how much lighter the 5.56 was to 7.62 carry more rounds. Then the military switches to a round that is nearly the same size and weight. The military had to come out with the 5.56EPR. And now they dumped it completely.

    • 5.56 will likely stick around for counterinsurgency and similar uses but we are probably steering back towards peer conflict. The question is how much of the decision was made by competent planners before they retired and got replaced with current leadership.

17. Interesting anecdote on bullets penetrating steel.

    During my college days, I spent all my free time back home working up loads for 22-250, 223, 44 mag, 357 max, and others. We were concerned about all those bullets skipping across the pasture and fields and into the woods, so I built a bullet stopper, something like a airgun pellet trap except hulkified. Never underestimate a farm kid who has access to all kinds of scrap construction materials, a circular saw, and a Lincoln welder. 18″ wide by 24″ high, angled about 45°, and made of two layers of half inch thick hardened steel plate. Still have it after all these years. It deflected everything I threw at it down into the ground. Steel core 7.62×39 rounds dimpled the surface, but all the others just splatted. I made a target frame of 1/2″ plywood same size, with a length of half inch rod down each side for for legs. Pound the legs into the ground to set the frame about 4″ in front of that heavy steel contraption, set 25 yards out from the picnic table, chrony at 10 ft and I was set.

    Staple a piece of paper on it with my grid of target dots, and commence to burning powder. Eventually, a good bit was shot out of that plywood, so I simply left the old paper sheets in place as a backer for a new target paper.

    Then Dad complained about the hole in the yard that the deflected bullets made. Well, we had a couple pieces of 1″ mild steel plate on the bench that we used as anvil surfaces. One had an oval slot torched through in one end, forming a handle that made it easier to pick it up and move it as needed. I took that steel plate and a couple of short pieces of 3/8″ rebar, and suspended it between the target frame and bullet deflector, so the bullets would splat radially out instead of down into the ground.

    Now, 1 moa = 1/4″ at 25 yards, so most of the more precise loads were essentially one ragged hole at that distance. I quickly found that 5 shots of 223 from the Contender would drill a hole through that 1″ steel plate, or just 3 from the 22-250. These were 50 grain TNT hp for the 223 and 55 gr soft point for the 22-250, so they were soft, relatively frangible bullets. That was pretty cool. Then, one day, I noticed a curl of smoke coming up after a string of shots, and I found that the heat generated by those drilling bullets had ignited the shredded paper that was on the back of the target frame. Now we’re at way cool.

    And then Dad complained about all the holes in his bench steel, so I welded them full and ground it smooth, and went back to using just the angled deflector but kept a bucket of soil handy to fill the hole in the grass whenever I was done.

    • I always wondered what kind of shenanigans a 22-250 could get up to with a 55g fmj from m193 let alone 855a1. Given you were punching steel with varment rounds I would imagine such a loading would thoroughly invalidate any realistically wearable steel armor outright..

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