Vltor VIS Grenade Launcher lower rail?

[Sid Post]

I ordered an LMT 12" rail mount M203. I was considering getting a Vltor VIS rifle length upper and mounting my 18inch Sabre Defense barrel in it. However, I don't see the lower rail I need.


The lower handguard is removable to give access for an installation of an M203 Grenade Launcher. All kits come standard with a light weight removable lower handguard. A strengthened lower handguard which accepts a rail mounted M203 or other rail mounted weapons will be available as an option.

Do I need to consider adding a Daniel Defense or Larue rail to my existing upper?

THANKS!

[KevinB]

While I have no affiliation with VLTOR - I would think it would be quite awkward to create a M203 capable lower rail.
I know from other testing that a rail mount system that does not tie into the barrel nut and locks soley in the 1913 rails will eventually ruin the rail. So ideally since you wont be using the stock M203 - you will need a rail that also ties into the bbl nut.
This is one reason the RISII solicitations (KAC URXII, DD RISII, and the SIR whatever) had a removeable lower to encoprate the M203 onto the BBL nut.

The Hk AG/C (sometime called the AG-36) mounts to a pictanitty rail and the bayonet lug - and has caused a great number of problems in that respect (cracking front sight gasblocks etc, KAC made a special lower locking M4 RAS section for 22 in this respect).

I've seen a MRP with a LMT rail mount fired (practise round) - so it can be done --- I just would not make a habit out of it.


However if your just shooting practise rounds (which are IIRC about 1/3 EFC) and mounting it mainly for looks you should be good to go -- however the recoil from HEDP will do it in pretty quickly (well in a wartime sense).

IIRC (and dont quote me) Mark Larue told people to go ahead and mount to his rails - and he beleived they would take what was thrown at them, (civilian application)

[Sid Post]

Thanks for the reply!

Are you saying the rail option will cause any rail to fail with reasonable use or just the removable lower rail options?

I've got a the railed LMT headed my way and I was told that was the best option by several credible people because it doesn't cause POI shifts with rifle ammo. None of them metioned any sort of rail failure and they all liked the easy mounting and unmounting.

[Snake]

While I have no affiliation with VLTOR - I would think it would be quite awkward to create a M203 capable lower rail.
I know from other testing that a rail mount system that does not tie into the barrel nut and locks soley in the 1913 rails will eventually ruin the rail. So ideally since you wont be using the stock M203 - you will need a rail that also ties into the bbl nut.
This is one reason the RISII solicitations (KAC URXII, DD RISII, and the SIR whatever) had a removeable lower to encoprate the M203 onto the BBL nut.

The Hk AG/C (sometime called the AG-36) mounts to a pictanitty rail and the bayonet lug - and has caused a great number of problems in that respect (cracking front sight gasblocks etc, KAC made a special lower locking M4 RAS section for 22 in this respect).

I've seen a MRP with a LMT rail mount fired (practise round) - so it can be done --- I just would not make a habit out of it.


However if your just shooting practise rounds (which are IIRC about 1/3 EFC) and mounting it mainly for looks you should be good to go -- however the recoil from HEDP will do it in pretty quickly (well in a wartime sense).

IIRC (and dont quote me) Mark Larue told people to go ahead and mount to his rails - and he beleived they would take what was thrown at them, (civilian application)


The H&K XM320 I believe was designed to have the same mounting capabilities that the m203 has, (i.e. either locking unto the barrel nut or be light enough to be rail mounted).

[KevinB]

I have a "passing" familiarity with the HK gl.

The intial mount used the bayonet lug to mount and a three pin shelf to lock to the barrel nut. When using a plastic top handguard
This was founf in testing to shatter the front sight gas blocks - so a solid gas block was then used for the UK SOF L119A1 (C8SFW) -- as an aside the KAC front sight is durable enough to use as a mounting point.

For using the KAC M4 RAS -- the "shelf is removed and it slides onto the M1913 rail section of the RAS -- KAC came out with the SAS RAS Lower due to this - as the drop in RAS lower will not stand up to the use as a GL mounting point (keep in mind the M4 RAS is simple retained by pressure of the left and right of the "upper" RAS segment - the delta ring and the forward handguard cap - it was never designed as a GL mount -- so the other lower (with some of the RASII lower properties - coldblue would be best for the history and chnages etc. on KAC parts)

http://img.photobucket.com/albums/v193/EvilKev/Weapons/HKGLandURX006.jpg

http://img.photobucket.com/albums/v193/EvilKev/Weapons/AG36006.jpg
Wow a unmarked LMT upper -- who knew ;)


Ignore my Canadian propaganda
http://img.photobucket.com/albums/v193/EvilKev/Weapons/ARMYdotCApic.jpg

contrived URX mount
http://img.photobucket.com/albums/v193/EvilKev/Weapons/EGLM.jpg

This allows the HK gl to drop onto the URXII RISII model (IMHO with a better concept that the selected DD RIS II but I digress)

In short the Hk Gl CANNOT be reliable straight to rail mounted ---
http://img.photobucket.com/albums/v193/EvilKev/Weapons/LarueAG36.jpg
If you do the only thing locking the GL to the rail is a pin system locking thru the mount to the rail -- and all the force is directed into those two pins.


edit sorry for hijacking the VIS thread.
If anyone has info they want to share (yet dont want it attrivuted to them or their company please dotn hesitate to PM me and I can post it with caveat it was given to me to post but is not attributed to anyone)

[Sid Post]

:cool: If only I could own an HK ... :rolleyes:


Really, I tried to find one. I would have paid $3K for it but, that wasn't possible. M-16 or HK Grenade Launcher .... LMT 40mm and .... :)