kishigo

Well I bit the bullet, so to speak. I cut the handguards down to fit. It's not exactly the way I want, but it'll do. I've been told that the handguards won't stay in with the way I modified them, but they seem fairly stable. I'm not planning on installing anything on them, so they should be alright. @survivalshop: I had previously measured and I recall about a 3/16" to 1/4" difference in the measurements. As I said before, I believe that the wider (longer?) delta ring and barrel nut on the LR-308 is what causes that difference. I just don't know, all things being equal, how DPMS made milspec handguards fit their A4 Classic rifles.

Actually, I'm 99.9999% sure that the barrel is indeed an ar-15 rifle length gas system. 1st of all, that's what it says at their website. 2nd of all, edgecrusher confirmed that the Rainier Arms barrel is rifle length. And thirdly, I can see the the gas tube protrusion into the receiver is about the same as my rifle length ar-15.

Well, here's an update. I ordered DPMS 2 piece handguards from Midway USA and they don't fit. They, like the other handguards, are about 1/4" too long. Or rather, the gas system is 1/4" too short. Either the Rainier Arms barrels are not made to DPMS's specs, or DPMS fibbed on their specs for the LR-308 A4 Classic rifles. If anybody has any input, please let me know. If anybody has an A4 Classic rifle with the mil-spec 2 piece handguards, perhaps if you could take a picture of your rifle sans handguards, maybe I can figure this out. Thank you Kevin

@unforgiven Thank you. I've been an unregistered lurker here for a while. It's just now that I'm involved in a build do I realize how much I don't know. That's why I'm here. Kevin

Thank you for the information. Yeah I thought that the Rainier Arms barrel was within spec. I just need to figure out how DPMS assembled the A4 classic using mil-spec handguards. If as you suggest, the old Colt handguards are out of spec, then it might be a simple matter of purchasing DPMS handguards. I saw them at their website, under the LR Platform section. They have the same model number as the ones under the AR Platform section. I assume that means they're the same for both platforms. Kevin

Hello, I'm trying to build an LR-308 A4 Classic upper using the following parts: DPMS Upper Receiver Rainier Arms Select 20" rifle length gas system barrel DPMS Chrome Bolt Carrier Armalite Clamp On A2 Front Sight DPMS 308 barrel nut & Delta Pack Old Colt Sporter Mil Spec 2 Piece Handguards The handguards appear to about 1/4" too long for this configuration. From comparing the distance from front sight to receiver with my ar-15, the Rainier Arms barrel does indeed look like it has a rifle length gas system. The gas tube appears to fit properly in the receiver. The only problem I see seems to be that the barrel nut and delta pack assembly are about 1/4" wider than the ar-15. When DPMS made their A4 Classic, does anyone how they got mil spec standard sized handguards to fit? Did they use a slightly longer gas system? Modified handguards? Any input would be appreciated. Thank you, Kevin