Jump to content

New to the M4


Recommended Posts

I was going to get a X400 for my XDm, but I'm a little over extended right now since I'm trying to get a LMT MRP piston upper for my AR15. My concern for the X400 would be the mode switch at the very bottom. My cell mate has one and we were looking at it's viability for a rifle/shotgun/subgun install. If you're looking at it for the lowest weight, that disappears as soon as you attach that XT07.

Another issue with the X300/X400 series on a side mount is the battery compartment latch is exposed. One bump and it'll loose it's lunch.

This photo shows you the slight parallax issues you'll have. Notice that the rail isn't aligned perfectly with the axis of the barrel.


You're better off without the XT07. It was hard to push. The constant on button was nice though. Plus, the 7 inches is no where near enough in my opinion.


Here is my Sidearmor with the Scout.



I tried to fit my Surefire X300 on a LaRue mount, and the XT07. Think about where the mount is for the X300/X400 series. It then has the large tail piece that sticks out towards the back. Then, the stiff wire protrudes rearward also. I would guess this combo would extend the package about 3 inches further back.


Now, you can get the XT07, and pull off their tape switch that has the picatinny rail mounted pad. Then, you have to buy a STxx switch like this:


They have several different lengths to get the switch where you want it. The silver plug simply pulls out of the XT07 tail piece. Then you replace it with this one.


If you mount the light on the left side (assuming you're right handed), you could easily run a short switch to the handguard. Attach the velcro to the handguard and the switch to a position you like. Personally, I like it under my support thumb.

If you try to mount the light to the right side of the weapon, you'll run into wire routing ****.



Here you can see that if the light package extended further to the rear, it would begin to crowd my hands.



With the X400 being on the bottom of the light package (stupid) it will introduce approximately 2 inches of horizontal parallax.



X400 - 450

XT07 - 165

ST Cable - 80




Scout Light - 475

ST Cable possibly - 80

The package from LaRue has a 7" switch.

(The price on the Scout light just went up in the past week about 50$.)



Also, I'm selling a 7" Surefire switch that I took off my Scout. It'll work on the XT07 tail piece if you want it. I never even used it.



If you want it, I'll sell it to you for 40 dollar shipped.


Just throwing you some options. This has been my big project for the past month or so.

Link to comment
Share on other sites

Great post SD. Thank you.


I was lucky/unlucky enough to find the only X400 on GB. Price was spot on. So I got it.


I am a lefty, not sure how it will affect my setup, but wel'll see.


Worse comes to worse, I'll throw the X400 on my LMT CQB (we have good taste!). It's already got a trji ta31trd, but no good light and no lasers.


I also ponied up at bought a SideArmor rail system. I spoke with Jeff, and I gotta tell you he was a great guy.




So now off to get the XT07 and some rail covers.


By no means I am disregarding your obvious knowledge with the M4, I just like playing it by ear.


Thank you for all of the intel.


Oh, threw on the telescopic stock tonight. Any of my gunsmithing takes great prep.


Beer. Check.

Smokes. Check.

Dog locked up. Check.

Copious amount of documentation. Check.

Doors are locked and the perimeter is free of zombies. :rolleyes:


10 minutes later...a done deal.


Pretty damn sexy.


I find myself in this hideous pattern of spending at least 2-3 times the price ofthe weapon on bells and whistles. Even on my Ruger K10-22T build.


Oh well, boys and their toys.

Link to comment
Share on other sites

Take some pictures when you get it done.


Being a lefty shouldn't be a problem. Just mount it to the right side.


Consider your sling options. The factory front loop isn't that great. I liked the rail mounted mount a 100x better. The Daniel Defense mount is the best. The one that limits rotation. I used a GearSector 2-point sling.

You can use the one long picatinny rail that comes with the sidearmor rail mounted on the right side. Light as far forward as possible, and sling mount at the very rear. That'll leave the left side of the weapon obstruction free.


As for rail covers, ladder rail covers work the best. Using ladder rails on the top rail will obstruct the iron sights significantly. It's usable, but not optimal. I'd only use them there with an optic. The Surefire ladder rails will offer the least amount of obstruction. The only reason I have them is to retain the wire and I am waiting on my Aimpoint T-1.


I tried Magpul XTM covers on my side rails. They weren't needed and didn't feel right. The ladder rails seemed best.

The larger covers over-hang on the factory handguard. So they get in the way of your hands.


Weapon build up's are always expensive. Lot's of trial and error too. I have high hopes for the MRP. I talked to LMT yesterday, and they said an order for one today would be delivered in October of 2010! 5 hours of machining time each. Insane times.

Link to comment
Share on other sites



Good luck with your wait.


I would try to go through a dealer, personally ... I know Rainier Arms has gotten them in a few times in recent history.


Whatever you do, the rifle is well worth the wait ... it's so slick, it's unreal.

Link to comment
Share on other sites

I sure as **** am not waiting that long. I've got a line on one. I gave up on the Masada. They've dicked that dog around way too long.


Is that one yours? Very nicely set up if so. I run a Magpul FDE M93b stock.


I'm looking at running one of those BAD's also. I'm pretty sure it'll work on my SMOS lower.


I was weighing which sights to get for a backup. Troy's or Magpuls? The cost and maybe the weight of the Magpuls are nice, any other bennies?


I'll probably go with the Aimpoint T-1 also and set another Scout light on it.

Link to comment
Share on other sites

Yep, that's my main rifle now.


I'm building a second lightweight AR from a BCM upper ... but it's kind of on the back burner for now.


I had a M93B before this UBR, the UBR is a much nicer stock.


The "BAD" is a fake, as the real BADs don't exist yet I don't think, but this one is bad ass, it's one piece welded, a complete replacement bolt release. It makes bolt carrier manipulation a dream.


I'd get the MBUS sights ... I had Troys on my last rifle, and they certainly are nice, but for something you almost never use I see no reason to spend $250+ on a pair of sights when you could spend $100 and get a lighter, cooler looking product that functions just as well.


Scout lights are great, buy your from Unobtanium if you're getting one lol, he has been trying to sell his LNIB one for ages IIRC.

Link to comment
Share on other sites

I was actually thinking about snagging his light, but forgot where he mentioned it. Figured he'd come through and mention it.


Unob, you have gaypal? You wanted 220 shipped right?


Does the front sling mount have limit stops like in the DD mounts? Or do they just spin freely?


Good to hear about the Magpul BUIS's.

Link to comment
Share on other sites

I was actually thinking about snagging his light, but forgot where he mentioned it. Figured he'd come through and mention it.


Unob, you have gaypal? You wanted 220 shipped right?


Does the front sling mount have limit stops like in the DD mounts? Or do they just spin freely?


Good to hear about the Magpul BUIS's.


I actually sold it already. Recieved payment today.

Link to comment
Share on other sites

First mikey jackson, now this!? :p


Glad you sold it. Couldn't believe it lasted as long as it did.


Me either. I am buying/looking for a 6P, 9P, or 6PD in LNIB condition for around $40-50 to use as a host for my new P60 module. It is going to be a monster :)


The module arrives monday :p

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...