I recently installed a knight’s RIS on my LMT 10.5 and noticed that the lower portion of the RIS is very loose. Is this normal? I have a RAS that when the lower portion is installed it is much tighter.
thanks in advance for any response
That is normal for the RIS. The RAS is a little tighter.
Both are antiquated rails IMO.
Rana
Both are antiquated rails IMO.
WHY??
I sure do like my RAS and has served me well for many years…
Just curious…
I, too, use the antiquated RAS. (It’s paid for.) When the VFG is pulled to the rear (Think: wringing a towel) rather than simply used as a pedestal, the wobble is mitigated.
Harv, I just snagged a, SAS lower rail for $55.00. Lowest price I have ever seen. i’ll let you know if it makes a difference.
SAS lower rail? What exactly is it , and will it work with both the RAS and RIS ?
thanks for the info.
SAS lower rails hook on like the RAS upper portion with the hook/set screw…
Hey Paul… did you snag that from Molon over at TOS???
If you did… you only got it cause I passed it up… I saw it only a few minutes after he posted it… I decided I wanted a CSM Dump pouch more…
The SAS Lower just has a latching mechanism with a screw like the upper part of the RAS. Makes for a very secure fit against the barrel nut.
me Personally… on a working gun… I find the RAS to be a very good rail… it is very secure and works well for me with a VFG and a light. There of tens of thousands in use by our Armed forces and since I don’t need freefloat accuracy out of a 4MOA Carbine shooting M855 spec ammo… it works for my needs.
Just my experience with them…
Here is a very informative website with details on the RIS/RAS/SAS rail etc.:
http://www.quarterbore.com/kac/index.html
I too had a RIS way back when. As more rigid units such as the FFRAS and RAS-II came out, I sold the RIS and never looked back.
Yup. That’s the one.
I always wanted one but just couldn’t see $100.00. Sticker shock.
I already have a CSM dumper and used it in our class. Snagged it for $30.00, delivered. Would like to find a few more though.
Simply put. There are better rails for the money currently on the market. The RIS/RAS are a compromise when it comes to a real world hard use rail systems; not much worse then having the lower half of the rail detach from your barrel when in “HARD” use.
I stole this excerpt from FROGMAN over on Tacticalforums.com as it illustrates but ONE example of the short falls of the RIS.
"The Teams use the KAC RIS. They do not use the totally freefloating version. I, personally, do not care for this rail system. My group and I tried to get the LaRue tube as a replacement but had the funding for a new rail purchase shut down and got stuck with the same old KAC item.
The KAC rail in use by the Teams has a removable bottom section to allow an M203 grenade launcher to be mounted to the barrel. This same removable section is usually pretty wobbly when a verticle foregrip is attached instead. One of mine actually came off in combat."
-Frogman
I have seen numerous of these antiquated rails both RIS/RAS STB. They would be fine for the recreational shooter; but aren’t well received in professional circles. Perhaps the 2 biggest reason these rails (RIS/RAS) exist is they can be easily removed and placed on another weapon in the field, and they can be used in conjunction with the also antiquated M203 grenade launcher. In short they are more of an answer to logistical concerns than to operational ones. Yes, I know, there is a fine line between the two.
Short falls include but aren’t limited to.
Keeping zero on Laser Aiming devices. The “wobble” is not conducive to keeping a true zero as the rail shifts especially when being handled. Not as much a problem with a brand new rail but over time it can become an issue.
Another arena they fall short in is CQD applications. Using a plastic VFG for hard CQD applications usually means running the risk of snapping a VFG with “HARD” use. One solution was the advent of the Aluminum VFG which in turn snapped or removed the lower rail with “HARD” use. There is nothing worse then having a handful of SPILT S*&! when you need that big piece of metal to go to work for you.
The RAS is a bit better than the RIS, but not much as it still suffers the same short falls to a lesser degree.
The new SOPMOD II kit actually has a 2 piece Daniel Defense Rail. I am inclined to see how it fairs. Some circle$ have opted for sturdy one piece FF rails which are superior in many ways in “MY OPINION.” The cost difference between the 2 piece rails and 1 piece FF models is almost nill, so why settle for less?
FWIW the KAC RIS/RAS are still in use as are MANY antiquities, albeit it is what is currently available. The advent of new weapon systems (i.e. FN SCAR and HK 416) and open purchase of current/up to date accessories are slowly addressing the problems presented by antiquated designs.
Rana - Thanks. Are KAC Free Float handguards in the supply system? Have they ever been used HARD? They predated LaRue (although LaRue, as usual, improved the design.)
The KAC FF tubes are on “designated” rifles only. The KAC FF tubes are not something issued out in mass; they come on a complete system and stay with that system. The KAC FF tubes used in these systems hold up well for there intended (specialized) purpose. And, I will agree that Larue does it better.
Thanks Rana for your insight…