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PRI Carbon Fiber Handguard Questions

Strykervet

ain'T goT no how whaTchamacalliT
Full Member
Minuteman
  • Jun 5, 2011
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    Pierce County, WA
    I have a few questions about the PRI handguards in carbon fiber. One is a 7" carbine length "Delta" model (it's triangular vs. round) and the other is their 15" round handguard.

    1. Is the 15" round handguard solid? Is it stable, as in it doesn't move or wiggle at the end of the tube near the
    muzzle when pressed? Is there ANY movement in that handguard at all?

    2. Can you mount a clip on NV module on the 15" PRI handguard? Is it rigid enough for that, and is that rail the
    same height as receiver?

    3. On the 7" Delta carbine model, does that front rail line up with the receiver? I'm under the impression the Delta
    isn't, but I'm not sure.

    Any other peculiarities about the PRI handguards I should be aware of? I've only used KAC before, so it's new territory. Thanks for any advice!
     
    1. Is the 15" round handguard solid? Is it stable, as in it doesn't move or wiggle at the end of the tube near the
    muzzle when pressed? Is there ANY movement in that handguard at all? Yes...as a rock! I have worked with the round styles from PRI for many years (and more recently the delta series) and they are tight as they get. No wiggle/wobble/etc.

    2. Can you mount a clip on NV module on the 15" PRI handguard? Is it rigid enough for that, and is that rail the
    same height as receiver? Yes...its solid enough for mounting of any forward-mounted NVD on the top handguard rail. As to the rail height matching...the PRI AR-15 handguard rails will match the top rail height of all AR-15 flattops. The .308 Handguard rails match up with the HIGH profile DPMS receivers, but are taller than the lower profile by ~0.075. In either event...you should be able to use the forward NVD despite that very minor difference in the rail heights.

    3. On the 7" Delta carbine model, does that front rail line up with the receiver? I'm under the impression the Delta
    isn't, but I'm not sure. The front rail lines up in terms of L/R, but it is NOT the same height as the receiver rail. The Delta's forward, top handguard rail will be slightly taller than the AR-15's receiver rail and BOTH the low and high profile DPMS .308 receivers.

    Any other peculiarities about the PRI handguards I should be aware of? I've only used KAC before, so it's new territory. Thanks for any advice!

    See above. Just one other thought in addition to the above...if you want same-height railed options for the Delta, PRI makes a monolithic/SPR-type rails that integrates the rifle's/carbine's receiver with the handguard to give you a full-length, same-plane rail interface. Just one more option.
     
    Hey, thanks, everything you said matches what PRI's guy told me when I spoke with him. He also said an SPR rail for the 15" tubes will be available in 3 months, maybe a little more. So if I feel I need that, I can always get it. I just really don't wanna use the KAC keymod. I don't like those systems, don't like the grip panels for 'em, etc. I prefer their URX 3.1 and their FF rail --I love KAC-- but they don't have one 15" long. Just that damn 14.5 keymod. So it looks like PRI.

    I may or may not get the SPR rail for the Delta carbine. I don't think I'll need it, and I'm trying to keep weight down as much as possible.
     
    PRI Forearms are very solid and HEAVY with the SPR Top Rail. I gave up on trying to keep this build light so now it has a Magpul PRS with MDT Adjustable Buttpad and 20" Ultramatch Barrel.

    7114665793_451d340a19_b.jpg
     
    Hey, that's a pretty slick rifle. I'll be building an SPR replica soon --I realized I have all the right parts to do one except the barrel!

    As for my other rifle, I kinda have to use the 15" PRi, that or the KAC keymod which I really don't want to use. I need the extra length over the 12" KAC rail I'm using because with a cantilevered USO scope, I don't have enough room for a PVS-27 when I score one. I know there's other tubes/rails, but those are the two I'm interested in. I figured on the PRi being lighter and definitely cheaper than keymod, since I have no keymod shit. I guess the top rail does make the PRI a bit heavier. But my Grendel, it's already damn near a 20lb. rifle! It's got a pretty heavy Satern bbl., KAC FF rail, USO SN3, VLTOR upper and an SDN-6 can, all of which make it heavier than normal. It does have a Noveske forged lower, A2 stock and Harris bipod, so that's not too bad. So I suppose the 15" PRI tube, and if need be the SPR rail for it, won't kill me I guess. And I need it if I want to use the PVS-27.

    I'm glad to hear the PRI tubes are good and sturdy. But do you feel that SPR rail is necessary? Is it not solid enough to mount a PVS-27 on the tube's rail itself without the SPR extension?

    I noticed you have your scope on a cantilever mount on the receiver portion (just like I'll have) and there's no room left on that top rail for anything, so what's the point of it? The front flip would have worked on the PRI rail the way I understand. I'm just curious here, not ragging on you at all.
     
    ADM Recon Mount w/ 20moa cant...no reason other than just having it on the shelf unused and since it works I left it.

    The SPR rail definitely "Locks" the forearm to the receiver and creates a perfectly continuous mount. There are two SPR Rails, one that is a full length which runs the whole length of the forearm and the version I'm using which allows for a front flip up sight.
     
    Yup, the PRI handguard is one of those things they shouldn't have changed when they went to the Mod 1. Combined with the single top-rail, it makes an AR into an excellent precision platform.
     
    I have both but another consideration is the Lancer. Super bad ass Hex in shape and very ridged. Very slick receiver to hand guard mount. Also very good looking. Like I said I have both and they are great , but the Lancer is much cooler looking!
     
    I just sold my SPR clone, but I liked the PRI forearm a lot. I never felt the need to run a swan sleeve on the rifle because I was running the ADM AD-Recon mount. Plus, I knew I was never going to run night optics. I ran the PRI gasblock front sight as well.
     
    It's carbon fiber, man. Tough and light. It's not going anywhere. Call PRI and they will help you with any specs you need. If you buy one from them and you don't like it, I'm sure they would return it. They are good guys that make good sh!/ in my opinion. The delta does line up vertically / horizontally with the receiver(if that makes sense). Anyway, call them.
     
    Well, there isn't a single bad review on here for 'em so that speaks volumes coming from you guys.

    I went ahead and pulled the trigger on the carbine delta tube --it was 15% off plus another 10% for vet discount, so 25% off total. Not bad, I should've ordered more but I need a 15" one... Oh well.

    But I don't need anymore advice regarding whether or not it's suitable or well built --I can tell now, can't wait until SBR's are official and then I get to use it. But if anyone has anything pertinent to add, tricks or tips or other details, those would be appreciated.

    Thanks for all the help guys, that PRI tube always looked good but I've been using KAC and nothing else for over a decade. Now I have another part to add to the arsenal.

    The thing that surprised me the most, however, was the weight. I actually expected it to be lighter. but to me anyway, it feels about the same weight as a KAC FF M4 tube (non-URX). Considering carbon fiber though, that only means it's stronger.

    They DID send me the wrong damn scope mount though --they measured the distance between outside and not inside the rings, so the USO SN3 didn't fit. However, PRI also has outstanding CS. They're sending me a new part and a return label, and are waiting to charge me until I decide if I want it or not. Midway could learn a lesson from these guys. Hats off to PRI, I'll be using them again.
     
    Yup, the PRI handguard is one of those things they shouldn't have changed when they went to the Mod 1. Combined with the single top-rail, it makes an AR into an excellent precision platform.
    Reviving a very old thread I know but I’m building a Mk12 Mod H kind-of clone (ie same barrel length, profile, handguard etc) but obvi gonna run a more modern can, that kind of thing. You mentioned with the top rail it makes for an excellent precision platform. Is it noticeably worse without the top rail? Optic mount is a Larue cantilever so I don’t need the optic to mount forward of the upper.
     
    thanks for bringing this thread back. I have got a AR15 build going right now (on the new 6ARC) and I'm considering a PRI Gen III Delta. Good comments above and I'm also interested in your questions about the top rail.