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MCX: Generation 3/SPEAR LT (Page 43 of 47)
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Originally Posted By medieval_flail: In order to know if the flex is related to accuracy they would need to use a wide spectrum of ammo. One would hope the accuracy issues and barrel flex aren't independent of each other. Originally Posted By medieval_flail: Originally Posted By Zerlak: Except it DID flex, just didn't flex as much. And I'm not referencing the handguard flexing but rather the screws applying pressure on the barrel. I've tested on a Spear-LT 11.5" that the handguard screws installed hand tight prevents the barrel from being removed. Those two small screws cause enough clamping force to retain the barrel without the barrel clamp screws tightened at all. When the barrel flexes, the handguard screws continue to clamp on the barrel and prevents it from returning to zero. Remove the handguard screws, it returns once pressure is released. I have a LMT 12.5", I'll give their test a go on mine soon. ETA: The barrel flexing has nothing to do with their test groups of accuracy when using the 77 grain IMI. They made it very clear the flex testing was considered a separate test from their accuracy evaluation. In order to know if the flex is related to accuracy they would need to use a wide spectrum of ammo. One would hope the accuracy issues and barrel flex aren't independent of each other. Individuals in this very thread have gotten close to 1 MOA groups with MCX, Spear-LT and Spear setups. They are capable of being rather accurate rifles, with the right round. Again, the barrel flex is not causing bad groupings unless you cause the flex to happen. You'll then get the flyer, as their video demonstrated, and it will then pull back to neutral/center. |
| I've been interested in a spear 7.62 x 51 but see some posts about flex and accuracy issues with this rifle. That's a lot of $$ for a gun w/ accuracy issues. I have not looked through every page of this thread but would like some real world feedback on the reliability and accuracy of this gun. |
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Originally Posted By FrankW134: I'm thinking about picking up a MCX-SSA trigger on the memorial day sale, but the Spear LT already has a decent 2 stage. Anyone with experience on the G trigger can confirm whether or not the juice is worth the squeeze? I read somewhere that the LT doesn't require the MCX version of geisseles triggers. I haven't yet replaced the one in my LT so idk from experience. |
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Originally Posted By KavonTN: I read somewhere that the LT doesn't require the MCX version of geisseles triggers. I haven't yet replaced the one in my LT so idk from experience. Originally Posted By KavonTN: Originally Posted By FrankW134: I'm thinking about picking up a MCX-SSA trigger on the memorial day sale, but the Spear LT already has a decent 2 stage. Anyone with experience on the G trigger can confirm whether or not the juice is worth the squeeze? I read somewhere that the LT doesn't require the MCX version of geisseles triggers. I haven't yet replaced the one in my LT so idk from experience. LT firing pin safety re-design permits AR-15 triggers to be used. |
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Originally Posted By Zerlak: LT firing pin safety re-design permits AR-15 triggers to be used. Originally Posted By Zerlak: Originally Posted By KavonTN: Originally Posted By FrankW134: I'm thinking about picking up a MCX-SSA trigger on the memorial day sale, but the Spear LT already has a decent 2 stage. Anyone with experience on the G trigger can confirm whether or not the juice is worth the squeeze? I read somewhere that the LT doesn't require the MCX version of geisseles triggers. I haven't yet replaced the one in my LT so idk from experience. LT firing pin safety re-design permits AR-15 triggers to be used. My question then, is it worth the $200+ to upgrade from the stock trigger? The factory 2-stage is much better than a stock milspec AR trigger, which I always replace with an SSA. My only gripe with the Sig trigger is that it feels too skinny, same with the charging handle. |
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Originally Posted By FrankW134: My question then, is it worth the $200+ to upgrade from the stock trigger? The factory 2-stage is much better than a stock milspec AR trigger, which I always replace with an SSA. My only gripe with the Sig trigger is that it feels too skinny, same with the charging handle. Originally Posted By FrankW134: Originally Posted By Zerlak: Originally Posted By KavonTN: Originally Posted By FrankW134: I'm thinking about picking up a MCX-SSA trigger on the memorial day sale, but the Spear LT already has a decent 2 stage. Anyone with experience on the G trigger can confirm whether or not the juice is worth the squeeze? I read somewhere that the LT doesn't require the MCX version of geisseles triggers. I haven't yet replaced the one in my LT so idk from experience. LT firing pin safety re-design permits AR-15 triggers to be used. My question then, is it worth the $200+ to upgrade from the stock trigger? The factory 2-stage is much better than a stock milspec AR trigger, which I always replace with an SSA. My only gripe with the Sig trigger is that it feels too skinny, same with the charging handle. Worth it is entirely up to you. If you prefer the Geissele feel, then yes it's worth it. |
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Originally Posted By Zerlak: We're talking about the group size with the IMI 77 grain, not the shifting barrel from flexing. All barrels flex when yanked/pushed, this is true for the AR-15 as well as any other barrel out there. Taking set, after flexing, is the issue with the MCX Spear-LT/Spear line and I'm willing to bet that has more to do with the handguard screws than the barrel clamp design. Originally Posted By Zerlak: Originally Posted By medieval_flail: Originally Posted By Zerlak: Originally Posted By Magsz18: Great video below: https://www.youtube.com/watch?v=s6efiG_1b7A Long story short, Spear LT accuracy sucks. I'm still not mad about it as I've never had any issue hitting anything i've aimed at with my 11.5 inch gun. It's been utterly reliable, accurate enough and really pleasant to shoot. Your 11.5" is a chrome lined phosphate barrel and their 16" will be a nitride. I'm curious if these manufacturing differences would potentially impact the accuracy. Also possible the Spear-LT just doesn't care for the IMI 77 grain. Uh I think it has something to do with the poorly designed barrel clamp which allowed the barrel to flex as seen in the video and verified by many others independently. This kills the rifle for me, it is simply too expensive to have both a flexible rail AND barrel. Maybe the CSAW clamp is different? We won't know till they actually get in the hands of someone other than CAG and the SAS. We're talking about the group size with the IMI 77 grain, not the shifting barrel from flexing. All barrels flex when yanked/pushed, this is true for the AR-15 as well as any other barrel out there. Taking set, after flexing, is the issue with the MCX Spear-LT/Spear line and I'm willing to bet that has more to do with the handguard screws than the barrel clamp design. ![]() SIG Spear LT (Gen 3 MCX) to 500yds: Practical Accuracy Different rifle from the first they used for the deflection test, but my guess is that the barrel in this one just likes the ammo they use. You can easily go from rack grade to match accuracy just by finding the right load for a given rifle, but as Henry points out, rack grade is sufficient for practical accuracy out to 500 yards. Barrel clamp is fine. This flex/set issue is not present in the Virtus, nor LMT’s MRP, only the Spear LT with it’s handguard screws has shown barrel deflection that seems to reset after the first round is fired. I would agree that the new handguard retention is a poor design, it doesn’t keep the handguard rigid enough to mount a LAM on the end of the rail without worrying about it losing zero, so it doesn’t accomplish its goal anyway. MCX uses an elegant mount design, but doesn’t pair well with IR devices. Hence why I think the gen 1 MCX, or the original LVAW, were a better choice for that purpose with their longer receiver rails, which again, I figure was part of why they had longer receiver rails to begin with. Virtus and Spear LT have shortened that forward rail to accommodate the shorter and longer barrels with one receiver; frankly, I think they should’ve just gone with two different receiver lengths, one at LVAW length for 9” or longer barrels, and a Virtus length for the shorter ones. |
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Originally Posted By rb889: Barrel clamp is fine. This flex/set issue is not present in the Virtus, nor LMT's MRP, only the Spear LT with it's handguard screws has shown barrel deflection that seems to reset after the first round is fired. I would agree that the new handguard retention is a poor design, it doesn't keep the handguard rigid enough to mount a LAM on the end of the rail without worrying about it losing zero, so it doesn't accomplish its goal anyway. The two rail screws are 100% the issue. They should have been flat or oval type and there should have been four of them, two rear and two front of the upper receiver where the +/- is. My LT fell over, landed on the SF Scout, deflected the shit out of the rail so bad I had to loosen the screws to straighten it out. Was torqued to 60/40.. I bought a ZRC for my Spear 308 and my Spear LT but ultimately decided to not use them and to remove the rail screws from both, problem solved. If you can accept the limitation of the MCX Spear platform and work around them, they are nice rifles for what they do. |
| I have a 300BO LT that turned out to be a shortstroking POS on the + position, even with a high backpressure suppressor. Sent it to sig, they say they fixed it. That was a lie, it still shortstroked subs on the reg. In my opinion, Sig is selling the 300BO LT with the wrong gas valve. Even if other people's gun functions 100% with the F02 valve, I still think it's the wrong valve. I had to blow $600 on a 6.75" barrel that I might not ever use, just to get the F03 valve because Sig won't sell it separately. That's a terrible way to get a gun to be more reliable, but I'm finally happy with it. |
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@Fuddy_McBootlicker That makes no sense that SIG wouldn't just sell the damn thing. Very off-putting from a CS standpoint. Word is it that KNS is working on something. Someone mentioned they were on a short list of things they said they were working on. Suggested everyone interested shoot them an email. They make some nice adjustable setups, I would LOVE to have a KNS plug for my Spear and Spear LT. |
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Originally Posted By Fuddy_McBootlicker: I have a 300BO LT that turned out to be a shortstroking POS on the + position, even with a high backpressure suppressor. Sent it to sig, they say they fixed it. That was a lie, it still shortstroked subs on the reg. In my opinion, Sig is selling the 300BO LT with the wrong gas valve. Even if other people's gun functions 100% with the F02 valve, I still think it's the wrong valve. I had to blow $600 on a 6.75" barrel that I might not ever use, just to get the F03 valve because Sig won't sell it separately. That's a terrible way to get a gun to be more reliable, but I'm finally happy with it. What ammo are you running that was having issues? did you try different ammo? I have gotten a shitty batch of cheap subs and it was nothing but problems |
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Originally Posted By hamsandwich34: What ammo are you running that was having issues? did you try different ammo? I have gotten a shitty batch of cheap subs and it was nothing but problems Originally Posted By hamsandwich34: Originally Posted By Fuddy_McBootlicker: I have a 300BO LT that turned out to be a shortstroking POS on the + position, even with a high backpressure suppressor. Sent it to sig, they say they fixed it. That was a lie, it still shortstroked subs on the reg. In my opinion, Sig is selling the 300BO LT with the wrong gas valve. Even if other people's gun functions 100% with the F02 valve, I still think it's the wrong valve. I had to blow $600 on a 6.75" barrel that I might not ever use, just to get the F03 valve because Sig won't sell it separately. That's a terrible way to get a gun to be more reliable, but I'm finally happy with it. What ammo are you running that was having issues? did you try different ammo? I have gotten a shitty batch of cheap subs and it was nothing but problems I'd bet a dime it's 208gr Hornady A-Max. |
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This thread has been a bad influence. Ordered all the components and stuff to load .300 Blackout (starting with 110 VMAX and 110 Barnes). Now need to decide on a .30 cal can that’s light and compact. I know sound performance will be less but want to keep the form factor. Attached File Attached File |
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Does anyone have suggestions for a good bag that doesn't look like a gun bag? I have an 11.5 LT with a surefire four prong and a surefire light that's just a little shorter than the muzzle. I have tried an Eberlestock Jacknife and a Cotopaxi Luzon 24L but they're both about an inch or two too short to hold the rifle with the stock folded and not have the muzzle stick out. All the other "SBR length" bags look too tactical or are an odd long shape. Would prefer not to use a guitar / tennis racket / etc bag as well. Thanks! Tom |
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That's tough. Form follows function and all that. I've got a bronze 32" voodoo tactical bag that's the least 'gun!' bag I've got. I think that's mostly down to color. It's carried my 11.5" and 9" MCXs. Edit: just looked through their lineup, might be discontinued. |
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Originally Posted By KavonTN: Does anyone have suggestions for a good bag that doesn't look like a gun bag? I have an 11.5 LT with a surefire four prong and a surefire light that's just a little shorter than the muzzle. I have tried an Eberlestock Jacknife and a Cotopaxi Luzon 24L but they're both about an inch or two too short to hold the rifle with the stock folded and not have the muzzle stick out. All the other "SBR length" bags look too tactical or are an odd long shape. Would prefer not to use a guitar / tennis racket / etc bag as well. Thanks! Tom I use an arcteryx assault pack 30 for work. |
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Originally Posted By KavonTN: Does anyone have suggestions for a good bag that doesn't look like a gun bag? I have an 11.5 LT with a surefire four prong and a surefire light that's just a little shorter than the muzzle. I have tried an Eberlestock Jacknife and a Cotopaxi Luzon 24L but they're both about an inch or two too short to hold the rifle with the stock folded and not have the muzzle stick out. All the other "SBR length" bags look too tactical or are an odd long shape. Would prefer not to use a guitar / tennis racket / etc bag as well. Thanks! Tom Try the vertx line. They make backpacks and sling bags designed for weapon carry. |
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Originally Posted By KavonTN: Does anyone have suggestions for a good bag that doesn't look like a gun bag? I have an 11.5 LT with a surefire four prong and a surefire light that's just a little shorter than the muzzle. I have tried an Eberlestock Jacknife and a Cotopaxi Luzon 24L but they're both about an inch or two too short to hold the rifle with the stock folded and not have the muzzle stick out. All the other "SBR length" bags look too tactical or are an odd long shape. Would prefer not to use a guitar / tennis racket / etc bag as well. Thanks! Tom I have a couple Elberstock cherry bombs. They fit my legacy with 12" barrel perfect. They're long but the colors are discreet |
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I literally just bought my 11.5 LT today but already have a Vertex Gamet. It fits perfect. Attached File Attached File |
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Keep hearing about the handguard deflection on the LT. i bought one back in Febuary and have not experienced that at all ran a carbine class and a night vision class using the NGAL on it running the Sig MSR 1-10 with a steiner MPS piggybacked in a reptilia mount. Held zero fine the entire time. Still loving this rifle. I did get a 200 rebate on the rifle after catching the scope on a good deal from PSA. Yanked the skeleton stock off and ordered the folding magpul from Sig to make it feel like the Spear 308. Really wanted to sell some stuff for the fullsize spear. But ended up grabbing an SFAR. Just too much money for it. |
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Attached File I’ve had a chance to put a couple hundred rounds down the tube and try a few setups. Swapped in a Tailhook compact brace vs the spinner deal. Tried a Aimpoint, Steiner 1-4 but settled in a EOtech. This is the final setup with a scout light and some DD backup irons. |
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Greetings! I currently own a Virtus and am considering adding a spear to the collection. Are parts interchangeable, or do I need to keep them separate? I'm sure it's been answered in this big thread so I'll start paging back, but though I would ask which may be quicker. |
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Originally Posted By JustinU235: Greetings! I currently own a Virtus and am considering adding a spear to the collection. Are parts interchangeable, or do I need to keep them separate? I'm sure it's been answered in this big thread so I'll start paging back, but though I would ask which may be quicker. Nearly everything is compatible between the Spear-Lt and Virtus. The biggest caveat is that if you want to use a Virtus handguard on a Spear-Lt, you will have to do a little bit of dremeling due to some slight differences in the receiver thickness at certain places. The Spear-Lt BCG and Virtus BCG are both compatible with each other, however they have different firing pin safeties, and I'm not 100% sure that the Spear-Lt hammer will trip the Virtus firing pin safety. Maybe somebody else here can chime in. Barrrels should just swap easily between them. Grips, stocks, etc.. All should swap easily. |
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Originally Posted By SpyHawk: Nearly everything is compatible between the Spear-Lt and Virtus. The biggest caveat is that if you want to use a Virtus handguard on a Spear-Lt, you will have to do a little bit of dremeling due to some slight differences in the receiver thickness at certain places. The Spear-Lt BCG and Virtus BCG are both compatible with each other, however they have different firing pin safeties, and I'm not 100% sure that the Spear-Lt hammer will trip the Virtus firing pin safety. Maybe somebody else here can chime in. Barrrels should just swap easily between them. Grips, stocks, etc.. All should swap easily. Thank you! I guess I should have checked the stickie topics because someone already put this all together. Whoopsie! ![]() https://www.ar15.com/forums/Armory/Sig-LVAW-MCX-Virtus-Rattler-and-Spear-LT-series-FAQ/45-524755/ |
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so are the accuracy issues overblown? I would not be using a LAM, DBAL, etc... Just red dot and light. For $2500 I don't want to deal with any issues. (16" flavor is appealing). |
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Originally Posted By Finslayer83: so are the accuracy issues overblown? I would not be using a LAM, DBAL, etc... Just red dot and light. For $2500 I don't want to deal with any issues. (16" flavor is appealing). I have not had any issues with mine. Plenty accurate at 100y that I would not hesitate to take it out to 6-700 if I had to. Do not have the DOPE on that yet as I need to load more 77gr. But did fine on 55-77. Even with the NGAL on it shooting from a Tripod on the front rail I did not have any issue with POI shift and ran 2 training classes with it. By far besides my match bolt gun second most expensive gun I own. Now looking to add an 11.5 to the stable. |
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Originally Posted By Finslayer83: so are the accuracy issues overblown? I would not be using a LAM, DBAL, etc... Just red dot and light. For $2500 I don't want to deal with any issues. (16" flavor is appealing). Largely overblown. Torque barrel clamp. Gun fine. If no LAM, DBAL, etc, I would suggest removing the rail screws and simply not running them. This will eliminate any possibility of the rail shifting and tweaking split receiver, thus affecting accuracy. The screws are not needed. |
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Originally Posted By Roadblock: Largely overblown. Torque barrel clamp. Gun fine. If no LAM, DBAL, etc, I would suggest removing the rail screws and simply not running them. This will eliminate any possibility of the rail shifting and tweaking split receiver, thus affecting accuracy. The screws are not needed. Originally Posted By Roadblock: Originally Posted By Finslayer83: so are the accuracy issues overblown? I would not be using a LAM, DBAL, etc... Just red dot and light. For $2500 I don't want to deal with any issues. (16" flavor is appealing). Largely overblown. Torque barrel clamp. Gun fine. If no LAM, DBAL, etc, I would suggest removing the rail screws and simply not running them. This will eliminate any possibility of the rail shifting and tweaking split receiver, thus affecting accuracy. The screws are not needed. This. Or, just run your LAM a bit further back or use a GBRS/HRF/PA/etc... mount that lifts and extends your LAM off the receiver rail. Either way is fine. |
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I have a love/hate thing with my MCX Spear LT. 300BO ammo is too expensive, it's unreliable without a $150 gas valve replacement, it's gassy AF and I shoot left-handed so it's even worse for me. Whenever the ATF approves the SBR deregistration, it'll go up for sale at some point. And yes I know, the ATF still keeps your info forever, and they won't refund my $200. That's not my reason for deregistering. |
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Originally Posted By Fuddy_McBootlicker: I have a love/hate thing with my MCX Spear LT. 300BO ammo is too expensive, it's unreliable without a $150 gas valve replacement, it's gassy AF and I shoot left-handed so it's even worse for me. Whenever the ATF approves the SBR deregistration, it'll go up for sale at some point. And yes I know, the ATF still keeps your info forever, and they won't refund my $200. That's not my reason for deregistering. |
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Originally Posted By ngc1300: What suppressor are you shooting it with? |
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Originally Posted By T-Minus: Just posted these in the other "MCX Spear" and was told to post them here instead. Caveat Emptor[/i] https://i.postimg.cc/Ss2gN3Rm/temp-Imageg-SRvlr.avif https://i.postimg.cc/wjw25gs6/temp-Image-Fbn2-Lf.avif https://i.postimg.cc/Sxx7x31H/temp-Image-Ue7-Kc-T.avif https://i.postimg.cc/RZYfVFHn/temp-Image-G6si2v.avif https://i.postimg.cc/MGjBcS73/temp-Imagek-U8psw.avif |
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Originally Posted By Zak-Smith: Which configuration Spear LT is this? We have shot the 9" 300's BO's with no problems, and the prior generation in 5.5 without issues. Originally bought the 9" 300BO. It short-stroked every single subsonic round on the + setting, with and without the suppressor. Changed out to the 5.5" Rattler upper and did the same thing. Sent it to Sig, they say they fixed it, and it still exhibited the same short-stroking problem. Changed the gas valve to an F03 and now it finally cycles reliably. After this ordeal, I'm ready to move on to a lever action or bolt action. When it comes to suppressed subsonic, I have other guns better suited for home defense. |
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Originally Posted By T-Minus: The design suffers from at least two inherent flaws. 1) The "diving board" doesn't have the same strength as a full "360" handguard. This should be obvious to anyone thinking about it. If you apply force to the side, instead of distributing that force across the entirety of the handguard, it is focused on a very, very small area. 2) To make things worse, that area is thinly profiled for aesthetics purposes (and perhaps weight reduction). That piece needs to be virtually solid. Compare/contrast to the LWRC IC-type handguard where the designers had the foresight to not make the thinnest part of the whole design the place that would be subject to the most force. Instead, they put the load bearing about 270 (or more) of the handguard. Not 15 or 20 degrees like the LT. https://i.postimg.cc/HkXqB0dv/temp-Images-Tk-Nc-V.avif But we're suckers for aesthetics (I'm not immune either), so we don't really focus on this stuff until we see something like this. Originally Posted By T-Minus: Originally Posted By JAG2955: Yeah, now tell us how it happened. The design suffers from at least two inherent flaws. 1) The "diving board" doesn't have the same strength as a full "360" handguard. This should be obvious to anyone thinking about it. If you apply force to the side, instead of distributing that force across the entirety of the handguard, it is focused on a very, very small area. 2) To make things worse, that area is thinly profiled for aesthetics purposes (and perhaps weight reduction). That piece needs to be virtually solid. Compare/contrast to the LWRC IC-type handguard where the designers had the foresight to not make the thinnest part of the whole design the place that would be subject to the most force. Instead, they put the load bearing about 270 (or more) of the handguard. Not 15 or 20 degrees like the LT. https://i.postimg.cc/HkXqB0dv/temp-Images-Tk-Nc-V.avif But we're suckers for aesthetics (I'm not immune either), so we don't really focus on this stuff until we see something like this. That isn't telling us what you were doing when you experienced the failure. Please tell us what you were doing to cause the upper to fail/bend. |
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Originally Posted By JAG2955: He didn't respond in the HK thread, either, so I'm guessing this was not normal use. It's actually worse than that. It wasn't undergoing any use at all. It's brand new and unused. The rifle had never been fired. It failed our testing protocol. |
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MCX: Generation 3/SPEAR LT (Page 43 of 47)
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