I’m in the process of narrowing down the list of components for my build. I like the idea of a monolithic upper because it affords an uninterrupted top rail, better rigidity, more optic mounting options, and free float of the barrel to aid in accuracy. I’ve been researching Vltor and Mega on this forum and elsewhere and these are my perceptions so far:
Vltor VIS
1.) Undisputed excellence
2.) MilSpec dimensions and tolerances
3.) Polylithic design - has a removable lower handguard intended to allow the attachment of the M-203 grenade launcher (yeah, like I’m ever going to need that), but the benefit to me would be better accessibility for more thorough cleaning
4.) From the pic on Ranier’s site, it appears that the lower portion of the VIS handguard has a double-layered heat shield. Not sure about this though… http://www.rainierarms.com/?page=shop/detail&product_id=605
5.) Non-proprietary in that you can use any stock barrel
Mega Monolithic Quad-Rail
1.) Relatively new to the AR scene, but has an excellent reputation for quality, fit, and finish. Consistently machine to MilSpec tolerances, not hit-or-miss
2.) Outstanding Customer Service - I’ve been pounding one of the owners with questions and he’s been super-responsive and happy to answer everything I’ve asked of him
3.) 7075-T6 construction
4.) True one-piece monolithic design
5.) Same as #5 above
6.) Have you checked out the pics on Mega’s website?? What a beautiful piece of work!! It definitely does not look like a cheese grater. http://www.megamachineshop.com/armscatalog/MTS-QUAD/loader.html
They both look awesome both functionally and aesthetically. The only thing I think I might be missing on either design are integral QD sling-swivel sockets (but I can add a DD rail mount QD swivel attachment point). Anyway, from what I’ve gathered I don’t think I could go wrong with either design, but I sure would like to hear from some of my more experienced brethren on what they might think about either of these.
BTW - The gentleman I corresponded with stated that the new rifle length monolithic upper would probably be out sometime around the May timeframe. He also states that whereas the useable length of the rail on the mid-length monolithic upper is 14.75", the useable length on the upcoming rifle length upper will be approximately 3.37" longer - FYI.
I have a VIS-2 (midlength). I have long arms, so if I could do it again I’d get a rifle length rail.
The VIS does have a single aluminum heat shield inside the removable lower portion. It works.
You do get more optics mounting options - saving a little weight by not needing a cantilevered mount like the LaRue SPR or LT-129, etc.
I’ve rebarreled since I got it already, and skipping the whole delta ring or FF rail install process is rather nice. The one thing I really do miss is the lack of integrated QD swivel sockets… I have a DD bolt-on and don’t like it hanging off there (though it works fine).
I had plenty of KAC panels, some Aluminum Black, and a Dremel sitting around, so I decided to be cheap and add indents on the rail for the KAC panel locking tabs rather than buy new ones. Works fine, but would have been nice to have those in the first place (I understand there is a patent issue or something).
I asked the gentleman at Mega about that, and he said, "These uppers do not have a heat shield. They actually stay fairly cool during normal use. However, they will get hot if you dump a few hundred rounds through it as fast as you can. "
As far as heat goes, I figured if I went with the Mega I could add some XTM Rail Panels to help out with that should it become an issue.
It would be nice to have a flush integral swivel socket, but the guy at Mega made a good point when he said, “We chose not to put integral QD sockets in due to the fact that everybody seems to prefer a different spot for them.”
One of the things that Vltor/Abrams Airborne does, outside weapons, is fabricate “housings” or “carriages” for high end computer components. Not gaming machines, but spy satellites with laser beams and shit. They take the knowledge gained from dissipating heat from a multi million dollar computer system and apply it to the VIS and CASV. Believe me, it works.
I never doubted what you said earlier. I was just passing along the Mega-guy’s comments. Sorry if my quick reply gave the appearance that I was questioning your experiences.
This is one of the things I am trying to figure out to help determine which platform will better meet my needs. Unless I find myself in a serious life-or-death defensive battle where I am sending rounds downrange just as fast as I can, will the lack of a heat shield make that much of a difference to me?? How would the Mega be any different in this respect than a FF Rail such as the LaRue or DD Lite Rail??
Any reason you aren’t considering the LMT MRP? They make a rifle length mono upper also…
Out of the two you asked about I would say the VLTOR but I have also read a couple positive reports on Mega… The VLTOR simply has a longer history and a good one at that.
I looked at the LMT, but according to this thread… https://www.m4carbine.net/showthread.php?t=41621&highlight=Vltor …it was mentioned that the LMT is a proprietary design and I’d be restricted to LMT barrels only. I was planning on going with either a mid-length BFH Noveske or BCM barrel.
I think there is some merit to the barrel discussion, however personally I don’t see a downside when LMT offers the options of any barrel that you could want in the future. I also like being able to simply swap the bolt and barrel and convert to 6.8… I also prefer the barrel profile but that once again that is simply preference.
I am a little bias because I run two MRP’s and have been very pleased with the rifles. YMMV Noveske and BCM are both excellent choices too…
I have a question on this. I know that when people talking about the rails being milspec they are talking about the dimensions on the individual rails.
They are comparing a VLTOR upper to a LMT upper. You can clearly see that the overall dimensions of VLTOR upper are wider than the LMT. When it comes to the overal dimensions what is considered “milspec”?
That is only the dimensions of the rails sections. I am talking about overall width.
I found this comparison of DD rails here -
Is there a standard or norm on the overall height and width? There is a fairly recent thread in which the OP is asking if a LaRue rail is worth the extra money over a YHM rail and one thing I saw several user complain about in regards to the YHM rail is that they are wider than the LaRue rails which made wrapping their hand around them an issue.
You can see in the comparison pic and see the VLTOR is much wider than the LMT and was wondering about having issues gripping it.
well for one thing LMT proprietary barrel mega barrel of your choice.
VIS not real monolithic and forged. Mega billet!
Mega Hex back design stronger for wildcat rounds…
PRICE MEGA
Mega accepts piston kits… VIS, LMT, COLT…nada
I’ve read a ton of posts here regarding forged vs billet, and many have pointed out that billet had to be made thicker to equal the strength and stability of forged because the hammering process makes forged denser and more uniformly aligns the molecules.
Some have also expressed concern about billet in that if the metal was not properly stress-relieved it could warp after machining. I specifically asked the gentleman at Mega about that very thing and he stated that they “machine these from a solid block of 7075-T6 [COLOR=“Blue”]stress-relieved[/COLOR] aluminum plate.” That was good to hear and sounds as if Mega is committed to doing things the right way.
LMT does not offer what alot of people want in barrels: a 1.10 6.8? no using SSA combat loads.
I also do not shoot 5.56 anymore because I prefer bigger bullets----I have a newly built 7.62x39 AR where the spent brass will be hydroformed to feed my 6.5 Grendel. If LMT made the MRP in those calibers it would be awesome. You can go to spikes for a 9mm MRP barrel, but given that option I’d love to see a .357sig MRP.
http://www.megamachineshop.com/armscatalog/MTS-QUAD/loader.html
