Just curious. Given that quad rails are out of vogue and that the DD Mk18 RIS seems specifically marketed as not being compatible with the 203.

Should I be looking at other DD models? Or Troy?

What model M203? Standard or railgrabber? What barrel length?

Rail mount, 12"

While the DD MK18 RIS II won't accept a standard M203, apparently a rail-mounted one will fit.



When it was brought up in a thread here a couple years ago, folks expressed concern about the amount of stress on the detachable bottom rail. Have you asked DD about it?

I had a DD m4 rail.  It worked but at some point it bent downwards.  That rail design was where a threaded round section was welded to the rail.  The bend was slight and in the area of the weld.  I replaced it with a superior weapons systems rail which is all straight extrusion that bolts onto a long steel barrel nut.  It has held up well but I moved my launcher a lmt pistol grip stand alone which I seen to use more.  The lmt mrp is the only system made to handle it.  Not sure any one else will warrantee their rail for this use.  I would choose a rail that is a straight extrusion that slides over a long barrel  nut which it bolts or clamps to.  Geissele mk7 national match probably would work.  I would mount it to a mlok rail too if  it clamped to the barrel nut.

If I did it again I would probably get the standard mount for use on rifles.  I really like the rail mount pistol with the 9" barrel.  Use a sling to brace it and it is very accurate.

I just got my launcher about 2 months back.

My long term plan is to get a standalone mount, but I already had this rifle w/URX 2 rail.
As far as I can tell, ~40 rounds of M781 haven't bent it.

I'd like more info on compatible rails if anyone has it.

Barrel mount

Which is no help considering that the rail mount one is the one that will be coming home with me shortly.

DD did respond to me and stated that the RIS II will withstand rail-mount 203 use.

Dummy round? Or FEL and super expensiveness?

The front fell off




It's my dummy round & photo prop.  Gotta glue it back together.  

That's good. 

You probably already know this, but always tighten down a rail-mounted launcher while holding it as far aft as possible against the rail slots, and ensure each clamp has a slot.

I didn't but it seems like common sense.

Waiting on Troy's response but for now the launcher, if the Form 4 ever comes back, will have a home on my Mk18

Awesome. Good to know as I'm waiting on two rail mounted receivers from TMGO that I'll be Form 1'ing. I appreciate you sharing.

Troy said no go...

 

Mega Megalithic upper, cut down by a machinist friend of mine.

I've used mine on a DD MK18 RIS II without issues. Granted, not a lot of rounds as they are scarce, but it seemed to hold up fine. Also had it on a KAC URX II Medium for a while. Currently have it on a Spikes Kaos Stock.