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Sig MCX Spear LT 7.62 x 39

ut755ln

Rub some dirt on it
Supporter
Full Member
Minuteman
Mar 24, 2011
526
362
Houston Texas
I know that given the nature of this forum that a lot of the post focus on accuracy and long range shooting of platforms. There will be a little of this in this post but there were other things to me that I wanted to share.

I have no idea if it was Sig's intent but in a way, the Spear LT is the best 7.62x39 rifle I have ever shot and it is not even close. I am not AK guy and I am sure there are some high quality builds out there that are really nice. When we went shooting, we had a KUSA KR 103, a Jim Fuller built Rifle Dynamics 702, and a Zastava M70. We shot three different steel cased ammos Wolf, Tula and Fiocchi. At 50 yards, 100 yards and 300 yards the Sig printed tighter groups for every shooter with every ammo and it honestly was not close. We were using a back pack as a rest so nothing fancy but we were getting right around 1.1 to 1.3 moa out of the sig. The best of the traditional AKs were a little over 2 moa.

To comment specifically about the Sig rifle, it is a thoroughly modern rifle. It has ambi controls like any M4. My friend installed a Geissle trigger (the spear was redesigned to take m4 triggers) and the Sig and RD clearly had the best trigger feel. It was the lightest of the three rifles. It was the only one with a free floated barrel. It was not an engineering project to get a surefire light and dbal on it because of the mlok rail. You did not have to do some kind of dust cover change to install an optic that holds zero or install some kind of side optic mount that you have to remove in order to clean the rifle. It has a built in adjustable gas system for suppressed and unsuppressed (we did not have a flow through can, we were using a Sandman S). This is subjective but to me, it was the softest shooting of the rifles as well. It is modular and you can currently get it in three different calibers (5.56, 300 blackout, 7,62x39). You change the barrel, bolt and magazine and you are good to go. Sig decided not to use AK mags but the steel mags he bought with the rifle functioned flawlessly. The rifle currently has around 500 rounds unsuppressed and closer to 2,000 with the can on and it has not had a single malfunction of any kind.

The Sig rifle was so good, it drove out whatever desire I may have had to ever own an AK. I am currently selling my AK, there just isn't a good reason to keep it around.
 
Thank you for this report. I think this is my next rifle, but I have been taking my time buying it since it is new and expensive. I am very close to just getting it… and what you wrote helps.
 
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I’m going to wait until they have a few more out there before I jump in but I’ve been eyeing the platform too. Probably a silly question but where did the LH charging handle go? I thought it was on the mil version.
 
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Thanks for your honest review of this rifle. I have been wanting a 7.62x39 in a AR platform that works unlike others that are out there. This is a expensive rifle so will be going through my safe to see which AK I don't mind selling to help fund the MCX Spear LT.
 
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Thanks for your honest review of this rifle. I have been wanting a 7.62x39 in a AR platform that works unlike others that are out there. This is a expensive rifle so will be going through my safe to see which AK I don't mind selling to help fund the MCX Spear LT.
Since that post, I actually bought a Spear LT for myself in 5.56 16". Now that I own it, I changed two things on the rifle that were an issue to me but may not be one to others. My rifle came with this minimalist folding stock. The length of pull on it was wrong for me so I bought a six position tube that replaces it and takes standard AR stocks. The base trigger in the Sig is a mil spec trigger and it feels like a mil spec trigger. I changed it to a Geissle SSA-E.

Every good thing that I had to say about my friends 7.62x39 you can say about the 5.56. We are getting tighter groups with the 5.56 but we think it is because we are using better quality ammo. For us, it has been right at 1 moa most of the time.

Another comment, I got my HUXWRX flow out of jail and have been using it on the Sig. I have also used a Sandman S. It is amazing how much less gas you get in the face vs an AR platform. Between the piston releasing gas and some amount going out the front of the can there is much less blow back and the receiver is noticeably less dirty.
Last comment, I promise. Dead Air makes an addition that you can install on your suppressors. They call it an E break and effectively it does three noticeable things. The first is that it actually acts as a break and makes the recoil impulse better. The second thing is that it allows more gas to escape out the front of the can and makes it function a little bit more like the HUXWRX flow. The last thing is that if I was going to guess, it makes the gun a little bit quieter from behind the gun (in effect you are kind of adding another baffle).

(DISCLAIMER) The quiet can nerds may have measured this at Pew Science and found the results to be different than I described. I do not want the lords of quiet cans to be angry with me. (DISCLAIMER)
 
I’ve had one for a while, it’s a great shooter. Consistent hits with cheap steel case ammo on steel at 400 yards with an Eotech. No issues running standard ammo, subs were a little finicky at first, after adjusting the gas block it’s been issue free. Unfortunately I’m moving to a non free state so it may have to go.
 
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I’ve had one for a while, it’s a great shooter. Consistent hits with cheap steel case ammo on steel at 400 yards with an Eotech. No issues running standard ammo, subs were a little finicky at first, after adjusting the gas block it’s been issue free. Unfortunately I’m moving to a non free state so it may have to go.
I’ll take it when your ready to offload ;)
 
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Thread revival. How does the sig perform with the flow can? Is it comfortable to shoot without ear pro? Just got a flow out of jail, considering going with this platform.
 
Thread revival. How does the sig perform with the flow can? Is it comfortable to shoot without ear pro? Just got a flow out of jail, considering going with this platform.
Great on the Sig, but better on other platforms. IMO you get the best bang for your buck with flow through cans on non gas adjustable DI rifles. They make a huge difference in the amount of gas that goes back to the user. While it does make a difference on my Sigs and HKs (both short stroke piston), it is not as noticeable to me. I wear ear pro when I shoot, even with the cans and while it is certainly quieter I am not the best person to ask about how much.
 
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iu

The main appeal for 7.62x39 was cheap ammo and terminal performance.
Prices on 7.62x39 have gone crazy though. For the AKs, they hit the base of the case with the fixed ejector really hard, making reloading brass for an AK kinda self-defeating.

In something with a dual plunger ejector like this, it makes hand-loading brass 7.62x39 more viable.

8901281-web-small-3_1.jpg


They’re using stronger bolt lug geometry with the Fosbery approach and a sprung firing pin. Nice....
 
iu

The main appeal for 7.62x39 was cheap ammo and terminal performance.
Prices on 7.62x39 have gone crazy though. For the AKs, they hit the base of the case with the fixed ejector really hard, making reloading brass for an AK kinda self-defeating.

In something with a dual plunger ejector like this, it makes hand-loading brass 7.62x39 more viable.

8901281-web-small-3_1.jpg


They’re using stronger bolt lug geometry with the Fosbery approach and a sprung firing pin. Nice....
One of the reasons Sig did this caliber was at the request of SOCOM. Putting on the 7.62x29 upper and using it in countries where that is the dominant weapon system helps hide the operators. No 5.56 brass laying around.
 
One of the reasons Sig did this caliber was at the request of SOCOM. Putting on the 7.62x29 upper and using it in countries where that is the dominant weapon system helps hide the operators. No 5.56 brass laying around.
There was a request for the same thing from somewhere in DoD back in the 1980s, and funding provided to Colt. The Colt 7.62x39 Sporter came from that. One of my neighbors had one in 1993.

iu


Then an echoed request from SOCOM came for a 7.62x39 AR for logistics and low-vis operations in the 1990s-early 2000s, hence the SR-47 from KAC and the Robinson Arms submissions. Magazines were always a bottleneck for all of these carbines.

iu

iu


If they offer it through the LVAW, that makes sense. There are photos with both JSOC and SOCOM shooters with LVAWs.
 
There was a request for the same thing from somewhere in DoD back in the 1980s, and funding provided to Colt. The Colt 7.62x39 Sporter came from that. One of my neighbors had one in 1993.

iu


Then an echoed request from SOCOM came for a 7.62x39 AR for logistics and low-vis operations in the 1990s-early 2000s, hence the SR-47 from KAC and the Robinson Arms submissions. Magazines were always a bottleneck for all of these carbines.

iu

iu


If they offer it through the LVAW, that makes sense. There are photos with both JSOC and SOCOM shooters with LVAWs.
This is the coolest post, I had no idea about the previous offerings. Thanks!