VLTOR VIS vs. VLTOR MUR + DD lite or KAC?

[Warg]

I'm about to begin another AR using a Noveske 18" SPR BBL mated to a Noveske lower, Magpul UBR, nice trigger, NF glass, etc- basically a high end piece. Trying to decide between a rifle length VIS versus a VLTOR MUR (which is on my shelf) and a Daniel Defense lite rail or possibly KAC. I don't have to use the MUR as it could be "assigned" to another I'm puting together for my spouse. The cost is a couple of hundred more for the VIS, but I can swing that. This is not a "what looks better" thread, I'm looking for pros and cons between the monolithic rail versus the standard types. The only practical advantage I see with the VIS is a one piece upper rail for mounting optics. Somewhat significant, but is this really necessary with a decent scope mount like the standard or extended LaRue?



Thanks,

Gene

[Southern_Partisan]

I've done some research recently on the Vltor VIS, and here is some of the information I've gathered from the Vltor reps and from knowledgeable friends here on the forum like rob_s and bkb0000:

1.) The VIS is a combination of things. The receiver portion is machined from a 6016 forging while the rail section is made from a 6063 extrusion, and only because you cannot weld 7075 (the MUR receiver is made from a 7075 Forging).

2.) The 60-series aluminums are highly corrosion-resistant.

3.) MilSpec dimensions and tolerances.

4.) Polylithic design - the VIS has a removable lower handguard intended to allow the attachment of the M-203 grenade launcher. An added benefit of this design is greater accessibility for cleaning and preventative maintenance.

5.) The Vltor VIS offers a single-layer aluminum heat shield inside of the removable lower portion of the hand guard.

6.) The VIS enables you to go with a pinned gas block (like on the Noveske Light Reece VIS 16" Upper), as opposed to one-piece monolithic uppers like that offered by Mega that require the use of low-profile set screw type gas blocks.

7.) The VIS is non-proprietary in that you can use any stock barrel.

I hope you find some of this info to be helpful. Good luck on your build!!

[Warg]

Very helpful, thanks.

I just discovered a disadvantage- there is a 5 oz difference in weight between the rifle length VIS (29 oz) vs. the MUR + DD lite 12.0 (24 oz).

[Warg]

I've spent some time reading the specs on both and user's opinions. I'm still on the fence, so here's a poll. Again, please keep this a price neutral when voting.

Thanks.

[Rated21R]

I chose to go with a MUR and a DD Lite. Saved a bit of weight and I really don't need the mono design of the VIS. Plus if I decide to go longer or shorter in the future I don't have to buy an all new setup, just a new FF rail. YMMV.

[TehLlama]

MUR with DD light is surprisingly lightweight, and attractive. I'm currently building a 14.7" in that configuration. Price differential is minimal.

If you want to go even lighter weight, the MUR with the TROY Extreme (TROY or VTAC flavors) is even lighter. I know you're thinking price neutral, but this is the lightest and cheapest option.

[Warg]

MUR with DD light is surprisingly lightweight, and attractive. I'm currently building a 14.7" in that configuration. Price differential is minimal.

If you want to go even lighter weight, the MUR with the TROY Extreme (TROY or VTAC flavors) is even lighter. I know you're thinking price neutral, but this is the lightest and cheapest option.

Agreed- I'm currently assembling a 16 lightweight middy with the Troy TRX and a 14.5 carbine with a VTAC Extreme, so I'd probably go with something different like the DD lite to complete the collection of lightweight rails :)

[Boss Hogg]

I'd go MUR with a LaRue 13.2". It will look better on an 18" barrel than a 12".

[Warg]

The longer rail is an option. I'm also considering the 14 DD lite.

[Belmont31R]

I don't personally like the VIS since the rail is very wide. I like the dimensions KAC uses, and which are mirrored by LaRue. Some of the DD rails have a bottom rail that sticks down further than either KAC or LaRue. The DD RIS II is build like the KAC, and LaRue where the bottom rail is tucked up more towards the center line than say the DD Lite rails and Omega. The KAC URX mid and rifle length comes with 5 QD sling points if you attach a sling, and the LaRue has two. The LaRue QD points are turn limited so the sling wont get twisted around. KAC are not limited in rotation which is unfortunate because otherwise is my favorite rail system.



The MUR is a good upper to build off of, and gives you more rail choices. I also like the LaRue billet upper, and there is nothing wrong with a regular forged upper either.

[Warg]

I don't personally like the VIS since the rail is very wide. I like the dimensions KAC uses, and which are mirrored by LaRue. Some of the DD rails have a bottom rail that sticks down further than either KAC or LaRue. The DD RIS II is build like the KAC, and LaRue where the bottom rail is tucked up more towards the center line than say the DD Lite rails and Omega. The KAC URX mid and rifle length comes with 5 QD sling points if you attach a sling, and the LaRue has two. The LaRue QD points are turn limited so the sling wont get twisted around. KAC are not limited in rotation which is unfortunate because otherwise is my favorite rail system.



The MUR is a good upper to build off of, and gives you more rail choices. I also like the LaRue billet upper, and there is nothing wrong with a regular forged upper either.

I do not like wide rails. Thanks for the tip. I REALLY like the URX II, but have not considered it as a choice due to the $$$ barrel nut wrench that is supposedly required for installation (though it looks like one could modify a standard barrel wrench to make it work).

I see that DD is coming out with a black RIS II too.

[Belmont31R]

I do not like wide rails. Thanks for the tip. I REALLY like the URX II, but have not considered it as a choice due to the $$$ barrel nut wrench that is supposedly required for installation (though it looks like one could modify a standard barrel wrench to make it work).

I see that DD is coming out with a black RIS II too.




Ive got 3 URX rails, and one of them came on the gun out of the box but the other 2 were installed after purchase of an upper. Gun Gallery in FL will install the rail for free if you buy the rail through them, and they do some quality work. They can cut down a FSB to fit under the rail if you're using a carbine gas system on either a middy or rifle length URX. For a middy gas system only the rifle length will work because the gas block would go right under the integrated BUIS, and there isn't enough room for both.


The URX is pricey but also consider you get the integrated BUIS. If you add up what another rail would cost, and a front BUIS its actually a decent deal. I also like that the BUIS is completely out of the way when not deployed, and just looks like part of the rail.


I have two uppers with RIS II rails. A M4A1, and M4A1 FSP. They are good rails too but don't have any QD points so if thats something you use then you'd have to get something to go on the rail. I like the integrated QD sockets as the clamp on ones tend to stick out quite a ways + cost extra. So if you took a DD RIS II, and added a QD clamp on peice, and a front buis you'd probably be at a higher cost than the URX.


I believe KAC is coming out with a new barrel nut wrench for the URX that is supposed to reduce the cost significantly otherwise as a mentioned you can get them installed professionally for free. I have a prototype of the new wrench but not 100% on the timeline for productions versions if they arent out already. Gun Gallery has done 4 builds for me now, and Im very happy with all of them. Neil is the guy you want to talk to there but he is going to be out of the shop until next Tuesday (called them today about something). They also do DD RIS II installs if you go that route.

[Warg]

They can cut down a FSB to fit under the rail if you're using a carbine gas system on either a middy or rifle length URX. For a middy gas system only the rifle length will work because the gas block would go right under the integrated BUIS, and there isn't enough room for both.



Good info, thanks. Regarding your statement above, do you know if Noveske's intermediate gas setup (halfway between a middy and rifle length I think) using the VLTOR GB will work fit under the rifle length URX II?

[Belmont31R]

Good info, thanks. Regarding your statement above, do you know if Noveske's intermediate gas setup (halfway between a middy and rifle length I think) using the VLTOR GB will work fit under the rifle length URX II?



Im pretty sure it will but Im not 100% on that.



Id give Wes @ MSTN a call to confirm if they will or not. (They also do URX builds but charge for the rail install even if you buy the rail from them).

[Warg]

I contacted Wes and we had a lengthy exchenge of e-mails. Very helpful guy, thank you for the reference. Wes isn't sure the KAC URX II will work with the 18" Noveske SPR BBL. He thinks it might, but hasn't installed any to date. He is supposed to get some in soon, however.

BTW, I've found some pics of Noveske BBLs with the VLTOR GBs mounted in URX IIs, but not the intermediate 18" versions.

At any rate, I think I'm going to punt the KAC rail option due to the limited ability to swap rails/barrels given the installation requirements, i.e., wrench/install $, loctite, etc. Wes helped steer me in this direction due to the fact that I'm not sure I'd be content with a semi-permanent install. I'm the type of person who like to swap stuff around a lot.

So it's LaRue, DD or VIS-3 now.