Does anyone know if the knights m4 carbine RAS will fit over the piston system on the model 8?  I called knights and they said it should, but they weren't positive.  Any help would be appreciated.  
Also, is there any rail that will fit if knights doesn't?

I have not used the KAS RAC but used Samson Star C. I like it. It is free floating.

Forgot picture.


Ok..it seems I am missing something on uploading from photobucket. Let me do a searchfor info and try again.

jdubya101 - thanks for the info.  Couldn't get the pics to work and i couldn't search for your PB.  I saw some pics on the STAG site.

Any others?

Daniel Defense Omega Rail Piston Carbine 7.0 is supposed to work with the Model 8.  I've seen pictures of it and read great things about the two together.  And remember the Sampson rail requires you to do some modification, where the DD omega rail doesn't (the omega rail is free floating too).  If you get the omega one you have to get the large diameter version of it as well.  If it wasn't for the price i would already be all over one for my Model 8, and alot of sites are out of stock on them.

so i work with someone who has both the RIS and RAS on his ARs and he looked them over and said there is no way the piston will fit without a fair amount of modification.  Looks like ill be going with the midwest industries one.  I cant justify the DD one being its at least double the price.

You can buy the Samson Star C from Stag Arms and it would be ready to mount on the Model 8.  I don't know for sure if it needs modified to fit the gas piston or not.  If it does, Stag I believe would do it for you.  You can buy the Model 8 with the Star C installed from the factory so I am sure that it works.  The question is if $259 is in your price range.

I went with the MI drop in.  Fits perfect, little bit of wiggle, but nothing horrible.  Worked well at the range and stayed much cooler than the plastics.

Anyone done the KAC on a piston? Also would like to see the pics of that if you were successful. I ended up trying the DD Omega Piston.

Just received my DD Omega 7' Piston (Large) for attachment to my Stag 8HL today. I will try to install tonight time permitting and post some pics. was on sale for $246.00 from PKFirearms which is $15.00 less than the Sampson Star from Stag,  so it was a no brainer for me :)

Stag confirmed to me that the Sampson Star-C rail will fit without modification if you purchase from them now. ( It should be noted older Sampson Star-C rails will NOT fit without modification, I asked since I had a 2HTL with the same rail, Stag informed that the rail was re-designed at the beginning of the year to accommodate the new piston system, but that older Star-C would not fit without modding.)

DD Omega 7" added




In hindsight I should have removed the front cap that holds the stock plastic hand guard in place, the cap prevents sliding things onto the rail from the front. Not a problem for things that clamp to attach like my lights, but I was NOT able to use my Troy Rail covers for either of the side rails.