Now that we have a user base, I’m thinking a single thread to capture all the little things the users learn about working with this gun that aren’t necessarily covered in official training.
Some of mine in no particular order:
the stock sling attachment points are soft metal. If you attach a sling using an HK hook or MASH clip (particularly the MASH clip) you will eventually eat through the factory loop, which deadlines the gun. Use something like the Blue Force wire adapter or the Urban ERT paracord adapter if you must use the factory attachment points.
Re slinging: IMO the best arrangement is to put some kind of rail-mounted attachment point up front as far forward as you can, and use the CAR-type loop on the back of the stock as the rear attachment point. I have experienced some ‘airspace deconfliction’ problems with the forward end of the sling mounted more toward the mag well. It is possible, with vigorous enough movement, to snag the sling on the charging handle and move the bolt out of battery enough to cause a failure to fire if the sling is mounted closer to the handle.
If your trigger sucks, shoot or dryfire the gun a bit. Mine felt like two pieces of 220grit being dragged against each other until about 300 rounds, then it suddenly smoothed out. It’s now about like a good stock Colt M4 trigger, which is fine for what I want to do with it.
Don’t SLAM the stock open except in emergencies. Standard procedure should be to depress the latch while opening the stock. No, you won’t break it if you do it once or twice or maybe even a hundred times, but why put the stress on the mechanism if you don’t have to? Replace the latch with the aluminum TangoDown part for added insurance.
Stuck cases can be mortared out just like an M4 - collapse the stock all the way and be sure to strike the ground squarely on the heel of the stock. No worries this way.
The H magazine floorplates will slide off. Best cure is to get 7.62 Magpuls and a hair dryer, and put them on sideways (loop running fore and aft). No more problems, plus your $40 magazines aren’t crashing into the deck completely unprotected. (If you aren’t dropping your magazines because they’re $40, you’re a fag.)
All M4 grips can be made to fit the SCAR. You simply sand about 1/16 off the bottom of the grip tang. Don’t panic. A stripped lower is $45 from FN if you think you fucked it up, but if you’re too dumb to do this you probably shouldn’t be trusted with any power tools at all. ALSO: Do NOT gorilla-torque the pistol grip screw down. You WILL crack the grip tang. The technical manual calls for UNDER 20 in-lbs, so if you need to (or are worried about it) put a TINY dab of blue Loctite on the screw before you install it. Without a torque wrench, just finger-tighten it, then snug it a quarter-turn past where it stops while just turning it lightly with your fingertips. That’s it.
Scope mounts such as LaRue or ADM need to be reversed so that the throw levers are on the opposite side from the side you are running the charging handle on. Unless you enjoy constant skinned knuckles, that is.
Mark ALL bolts/screws/fasteners with a paint pen. The factory ones don’t move, but anything you added to the gun can and will loosen. This ain’t your daddy’s Oldsmobile, and it will beat the shit out of just about everything you attach to it. That’s the cost of a 7.5# 7.62 rifle.
on that note, make SURE anything you mount to a rail is pushed FORWARD firmly before you lock it down. If you don’t (no matter how tight you have the latch) , it will slide forward under recoil and batter the rear edge of the next rail slot. Ask me how I know. :-\
The factory brake, while it does reduce recoil, is absolutely deafening. Don’t be afraid to replace it with a flash suppressor. The gun doesn’t recoil so much more that it hurts, and your ears will thank you. This PSA brought to you by the Current Sufferers of Brake-Induced-Tinnitus Association.
if the stock rattle bothers you - one place you can address it easily is the buttplate. Take a piece of bubble wrap and stuff it into the bottom cavity in the stock toe and reinstall the buttplate. Now the only thing you have to silence is the cheekpiece.
13: The front sight hood can be easily cut/ground down to closer replicate most M4 front sights. This stops the hood from blocking your vision if you use a red dot with the irons up, and it allows you to place a flashlight further back on a PWS rail if you happen to have one installed. When removing the front sight to cut/grind on it, the retaining nut has a pin through it. You can shear the retaining nut right off if you don’t remove the pin first (ask me how I know).
14: The Magpul safety selector made a huge difference for me. Personal preference, but I recommend you at least try one out.
15: Be careful when setting up double feeds for malfunction practice. There is a chance the round you throw into the chamber can work its way above the bolt and ride inside the top of the bolt carrier (sort of like an M4 bolt override…sort of). The rifle will function, but will have trouble seating and feeding from new magazines if you have the muzzle pointed up. The rifle has to be disassembled to remove this round. I shot about 3 mags worth with a round floating up there, and was ready to shit can some magazines because they were producing double feeds after I sent the bolt forward.
16: Hopefully an obvious one, but PMags need to be slightly modified to not damage the bolt catch/release. There is a ton of info out there about this, and it only takes 10 seconds per mag and a bastard file. USGI, SF60, Tango Down ARC, Lancer, and Troy mags all work without modification (and I’m sure others too, those are just what I have experience with).
As we go along, there will definitely be some merit in adding relevant photographs in a few places (i.e. exactly how the grip tang sanding mod should look, where trigger surfaces can/can not safely be polished, where to remove material from a standard PMAG for compatibility, or the best sling mounting arrangements), but this is solid content, to be sure.
Interestingly, the one advantage to being left-handed here is that optics can be mounted as per usual (meaning no need to reverse mounts) when the charging handle is mounted on the right side of the gun.
I also retrofitted the Magpul selector levers, but did not find that I needed – or really stood to gain – from reversing the long and short levers, as one might otherwise expect a southpaw to do.
Agree on the need for brake replacement. I substituted a BattleComp (16s), but a flash suppressor is still going to be the more neighborly option if you plan on using the rifle for a lot of collective training.
The 7.62 magpuls are a great idea. I’ve been able to wrestle them on in the conventional orientation by stretching them manually (and it’s a nice mini isometric workout too).
You can get a MIAD grip with the large backstrap to fit, despite the lower having a different curvature than an AR above the rear of the pistol grip. Use a dremel and take your time on the backstrap. I suppose you could do it manually, but you’ll be at it longer. The dimensions inside a mounted MIAD are different as well. The snazzy rubber cap that they give you with the 123A battery storage core won’t allow you to lock the core into the grip on a SCAR. I had to trash it and use foam earplugs as stoppers for the batteries. It’s not watertight, but it beats having rattle in your grip, or being stuck with the default 3 rounds of 5.56 in a 7.62 gun and having no extra batteries.
The Super SCAR trigger is an excellent upgrade, if you feel like ponying up for it, and can find one. The manufacturer has an excellent YouTube video out there that, coupled with the instructions, made it easy to install. It has a feel similar to my SSA-E in my AR. Geissele has included a proper length grip screw in the kit now after folks had to cut theirs to avoid interfering with the trigger.
Think long and hard before you decide to ditch the factory front sight for something rail mounted. There’s a roll pin through the cap on the windage screw that you will shear off if you just try to muscle it off. There is also a retarded number of little springs and ball bearing detents in various hidden places. If you insist on exploring this, put a large Ziplock freezer bag over the work area and explore inside there. Those ball bearings are a major pain to find when they go ballistic. In the end, I went back to the factory sights for various reasons, including that the gas block rail I thought would allow me to slide things down the top rail wasn’t quite flush enough to allow it. I also tried out a pair of Troy micro flip ups, thinking that the SCAR has more offset (it apparently doesn’t) but these didn’t co-witness with the optic. (I am also about $75 in the hole from doodads i had to sell at a loss or pay shipping to return. Avoid my fate.)
I swapped the charging handle to the right side to avoid broken thumbs from me or a friend having a brain fart and using a mag well grip. It’s consistent with my AKs, and allows me to manually lock the bolt back more easily than the default left side. YMMV.
If you choose to use the Tango Down SCAR panels and they’re loose and rattle like mine did, take a small piece of electrical tape and cover the little nub on the rail side of the locking tab. The tape will help fill up the rail slot and prevent shifting.
Will definitely sticky it in time, but we’ve found that if you do it too soon, it actually grinds thread development to a halt, as folks soon stop paying attention for whatever reason.
Also, if you’re interested in following this thread (but not a contributor at this point), please remember to “subscribe” to this thread using the thread tools menu selection. Posts which are added simply to tag the thread will be pruned as we go along to keep this as streamlined as possible. Thanks.
The SCAR factory folding rear sight is the same height as any standard AR rear sight. The height above the rail is the same with the factory sights or by removing the factory sights and installing AR flip ups on the top rail.
This is also confirmed by various cowitness mounts. The Larue LT660 is a lower 1/3 cowitness on an M4, and is the same on the SCAR. The Larue LT751 is an absolute cowitness on an M4, and is the same on the SCAR.
The factory front sight post is very tall, because is starts lower than the top rail. When measuring from the top rail to the tip of the front sight, the factory sight is the same as a set of mounted traditional M4 sights.
I have over 6k thru my scar the trigger didnt start off great but after a few thousand rounds its good. I had Marvin Pitts cut and thread my barrel to 14.5 and perm attach a PWS triad. For some reason prob the crown my scar shoots awesome groups after the cut. I hated the front sight assy so i put on the promoted pawn front sight rail and was using daniel defense front and rear sights with a larue 660 tall t1 mount. This worked great but changed it up a bit and got a larue HK t1 mount and troy micros and its great. My promoted pawn rail lines up perfect with the upper reciever unlike BaronFitz so i imagine they might have some QC issues. The entire tangodown scar line works great for me i love the charge handle angled up and the new rails are tits. EDIT: I didn’t need to replace the gas control screw after the barrel chop it runs fine with steel case junk to 5.56 spec ammo no prob. The BFG UWL works great to sling to the middle hk loops quiet and zero damage
I had to slightly modify my lancers because the bolt release was rubbing on the side of the magazines. The tip of my release barely touches the followers on lancers also and I’m afraid it will start to slip as the plastic is worn away. Check your rifles and lancer mags to make sure this is not happening. From now on I will only use USGI mags but I will try the new generation pmags when they come out.
Related to this, if you have a Bobro mount and are running the charging handle on the left side, you don’t need to reverse the full mount. You can detach the base of the mount and flip that around instead, so that the weight of your optic is still kept towards the middle of the rifle instead of being moved forward by reversing the entire mount.
I hated the front sight assy so i put on the promoted pawn front sight rail and was using daniel defense front
I did the same. However, I installed the DD front sight on the top rail and then used the promoted pawn rail to attach an offset light mount (ala’ AK + Ultimak) and this allowed me to not crowd the light so much. The standard FS, with its hood, took up far too much of a RDS window when deployed (I am one of those, ‘sights up’ people). DD sight was a good improvement.
I like the Tango Down CH but unlike many, chose to run it down rather than up on the left hand side after monkeying around with it at the range. Some found angling it down meant that their knuckles dragged on the barrel attachment point but I found angling it up meant scraping my knuckles on my optic mount (it’s a reversed LaRue mount; same way I’d been running it since about day 1).
The Tango Down buttstock latch I’m so-so about. The stock can’t be, ‘snapped’ open in the same manner and I also worry about which part will break first, the button or the latch (before, this was a non-issue because the button was the obvious answer).
Using a belt sander to take down the nubbin’ on the A2 grip makes a world of difference and doesn’t involve either a) buying a SCAR-specific grip nor b) modifying the receiver. TD makes my favorite grip but after taking off the nubbin’ the grip is close enough that I didn’t bother with either step.
Not all mags will work. Well, all in-spec mags will work but some of the others, like PMags, require some minor modification in order to not damage the rifle. There’s a video about this someplace but it’s just a dremel to the back, ‘U’ on the PMag to fix it.
A simple slingshot to the CH makes for an easy bolt release during a reload but many AR guys will just stick to a slap or a thumb on the bolt release. On the SCAR I quite like smacking the CH instead of hitting the release. YMMV.
Agree. I’ve seen a few related threads on FNF, including this one, but it would be good to consolidate as much of this kind of learning as we can here.
He’s the only one( and the first)I know of running that set up on FNF. Could that be Tom? I guess he can come out and tell us!
On the topic, the more you shoot it, the better trigger gets( ain’t that true with most, if not all, guns?). I noticed it as early as around 60 rounds down the pipe.
Tom, I think you just saved me a nice chunk of change. I was going to have to get the Vltor offering with the QD socket, but this coupled with the tip on how to eliminate rattle should get me squared away. Thanks!
