AR Sponsor
Posted: 11/10/2020 4:28:43 PM EDT
| What’s the difference between the original RIS and RIS II? |
The RIS was the earlier version of KACs 7” drop-in quad rail handguard. Was not free-float and could be swapped in to replace plastic/standard handguards without any modification to the host weapon. The later version (RAS) had a few changes that enhanced lockup when installed. The RIS II that was eventually adopted (through the RAS II solicitation/program) is manufactured by DD. There are a few variants/different lengths. It is a FF handguard and the M4A1/GLSSC models could FF an M203 GL. Mk18 version could not. All of them require tearing down the host weapon system to install the required barrel nut and a LPGB (except on the FSP models). Attached File For more info on the RIS II take a look at the SOPMOD Block 2 pic threads (M4A1 and Mk18/CQBR). |
|
Quoted: Thanks, this sounds like 2 companies competing for a share of the market. Has anyone written an idiot’s guide to RIS, RAS, etc? I think that’s what I need. Lol Not really, although they did both compete in the RAS II program (the KAC rail, a URX 2, was never adopted in that role). KAC RIS/RAS was early SOPMOD program stuff (SOF weapons in the late 90s-early 2000s) and then eventually adopted into the MWS program (standard issue stuff from the mid 2000s through current day). The RAS II program (DD RIS II) was an update to the SOPMOD program (SOF weapons in the mid/late-2000s through current day) and that’s it. The M4A1 DD RIS II is currently being phased out in USASOC with the Geissele Mk16 and there’s talks of an update to the Mk18/CQBR with an 11.5” barrel and new rail system. So one was an update to the other on a small amount of weapons and everyone else is still using the KAC RAS, so wasn’t much competition between the two. |
|
Just to clarify, the Knight's Armament RAS II was a commercial only item. The rail submitted by Knight's Armament that lost out to Daniel Defense was the 7" URX II. KAC was a bit sour since the DD didn't fulfill all of the requirements. It was supposed to be compatible with the M203A2's QD mount and it wasn't. So SOF issued rails went: RIS (Knight's Armament) M4 RAS (Knight's Armament) M4A1 RIS II, M4A1 RIS II FSP, and MK18 RIS II (Daniel Defense) MK16 13.5", USASOC only (Geissele) Non SOF issued rails went: M4 RAS, M5 RAS (Knight's Armament and P&S Products) |
|
Quoted: The RIS was the earlier version of KACs 7” drop-in quad rail handguard. Was not free-float and could be swapped in to replace plastic/standard handguards without any modification to the host weapon. The later version (RAS) had a few changes that enhanced lockup when installed. https://i1.wp.com/hurricane-butterfly.net/wp-content/uploads/2018/06/RAil.jpg?fit=640%2C480&ssl=1 The RIS II that was eventually adopted (through the RAS II solicitation/program) is manufactured by DD. There are a few variants/different lengths. It is a FF handguard and the M4A1/GLSSC models could FF an M203 GL. Mk18 version could not. All of them require tearing down the host weapon system to install the required barrel nut and a LPGB (except on the FSP models). https://www.AR15.Com/media/mediaFiles/294984/B5CA6866-2179-4F38-8377-D40A6FFE0F9E_jpe-1677997.JPG For more info on the RIS II take a look at the SOPMOD Block 2 pic threads (M4A1 and Mk18/CQBR). The top picture is a rail that was never issued in the US Military. That's either a UK or Canadian RAS, I'm not that familiar with non US stuff. The M4 RAS doesn't have a screw on the bottom rail. |
|
Quoted: The top picture is a rail that was never issued in the US Military. Quoted: The top picture is a rail that was never issued in the US Military. That's either a UK or Canadian RAS, I'm not that familiar with non US stuff. The M4 RAS doesn't have a screw on the bottom rail. Here's a RAS set from a US Navy CQBR and you can see it has RIS numbering like the one in RJeff21's pic. Attached File Attached File I couldn't tell you how many UK-SAS Bottom Rails were issued, but they're fairly common on the old Navy CQBR uppers I've seen. Most had the regular (no screw) RAS bottom rail (but with RIS numbering) and a few had the old RIS. |
|
Quoted: Yes they were. That bottom rail is called the UK-SAS Bottom Rail (I think because it was designed at their request) but our military bought them too. Here's a RAS set from a US Navy CQBR and you can see it has RIS numbering like the one in RJeff21's pic. https://www.ar15.com/media/mediaFiles/13082/F8BEA101-3282-4445-A24D-87CAF682FA97_jpeg-977646.JPG https://www.ar15.com/media/mediaFiles/13082/E54FD43C-3A3D-4289-A7CC-C1C78A6507EB_jpeg-977655.JPG I couldn't tell you how many UK-SAS Bottom Rails were issued, but they're fairly common on the old Navy CQBR uppers I've seen. Most had the regular (no screw) RAS bottom rail (but with RIS numbering) and a few had the old RIS. Interesting. What evidence do you have of that? |
|
Quoted: Interesting. What evidence do you have of that? Four years ago I drove to Anniston Army Depot and picked up 27 of these CQBR uppers from the DLA. I had my pick of the 84 in the crate, and the whole crate shipped from NSWC Crane, as received by DLA ANAD. You can see the Navy GM tags still on some of the uppers. Attached File Attached File Attached File Attached File I'm guessing the "RIS II" written on the tags meant they were originally slated to receive the RIS II upgrade, but I don't know. None of the 84 had a RIS II installed. A couple of them had red tags indicating they were rejected for failing erosion gauges. |
|
Quoted: I took the above photo on my desk from one of the ex-Navy CQBR uppers at my office. Four years ago I drove to Anniston Army Depot and picked up 27 of these CQBR uppers from the DLA. I had my pick of the 84 in the crate, and the whole crate shipped from NSWC Crane, as received by DLA ANAD. You can see the Navy GM tags still on some of the uppers. https://www.AR15.Com/media/mediaFiles/13082/5D6DD749-8AE6-465F-B895-2B6418029663_jpe-1696579.JPG https://www.AR15.Com/media/mediaFiles/13082/F88CF7F0-A552-4B93-89EC-02A5A9A60328_jpe-1696580.JPG https://www.AR15.Com/media/mediaFiles/13082/34514CF8-BB4F-4D42-9434-8772A53ACDB0_jpe-1696581.JPG https://www.AR15.Com/media/mediaFiles/13082/957BC709-89CC-42B2-968F-72883C74ECE3_jpe-1696583.JPG I'm guessing the "RIS II" written on the tags meant they were originally slated to receive the RIS II upgrade, but I don't know. None of the 84 had a RIS II installed. A couple of them had red tags indicating they were rejected for failing erosion gauges. Neat. The 2010 production date on the UK-SAS or whatever it is called is well past when they started making 10.3" RIS II URGs too. I wonder if they were COTS? |
|
Quoted: I took the above photo on my desk from one of the ex-Navy CQBR uppers at my office. Four years ago I drove to Anniston Army Depot and picked up 27 of these CQBR uppers from the DLA. I had my pick of the 84 in the crate, and the whole crate shipped from NSWC Crane, as received by DLA ANAD. You can see the Navy GM tags still on some of the uppers. https://www.AR15.Com/media/mediaFiles/13082/5D6DD749-8AE6-465F-B895-2B6418029663_jpe-1696579.JPG https://www.AR15.Com/media/mediaFiles/13082/F88CF7F0-A552-4B93-89EC-02A5A9A60328_jpe-1696580.JPG https://www.AR15.Com/media/mediaFiles/13082/34514CF8-BB4F-4D42-9434-8772A53ACDB0_jpe-1696581.JPG https://www.AR15.Com/media/mediaFiles/13082/957BC709-89CC-42B2-968F-72883C74ECE3_jpe-1696583.JPG I'm guessing the "RIS II" written on the tags meant they were originally slated to receive the RIS II upgrade, but I don't know. None of the 84 had a RIS II installed. A couple of them had red tags indicating they were rejected for failing erosion gauges. |
AR Sponsor