So I’m building a gun specifically for IR and NVG use, got a lot of night hunts and pest control planned for this year. I’m familiar with the issue of rail deflection especially with MFAL,s and want a really solid rail to mount the laser on. Outside of going with a monolithic design, what is one of the best rails to use as a laser host? The Daniel Defense RIS 2’s seem to do well but I’d prefer to go with something a little lighter. I’ve tested some of the rails I have laying around, for example a forward controls RHF I can put a half inch of flex with my thumb and index finger on the muzzle device. Looking for mlok rails if possible that won’t have a crazy poa/poi shift. Has anyone had any experiencd with the centurion CMR rails? The ones I’ve handled seem to be a little thicker than most other mlok rails
Larue followed by Geissele (original, MK 2, 4 AND 8) for minimal shift. I’m sure that there are others but these two are all that I’ve used. Or, like you said, there’s always monolothic.
I’d love a monolithic like an LMT MRP but damn they’re expensive. Just can’t afford the whole thing versus upgrading the rail on my existing upper.
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I doubt that the Centurion Arms AR-15 handguards would do particularly well compared to others on the market when it comes to deflection, given the small size of the barrel nut, though this is purely a SWAG and not something I know for a fact. Quad rail handguards might be rigid as **** given all the material on them, but they can still deflect if their interface with the barrel nut gives them room to move.
My question is, what kind of shooting hunting are you doing while hunting? Handguard deflection (obligatory screed about how handguards are not the same as rails, handguards can have rails, but you can also have just rail sections, etc.) is a real thing, but if you’re mostly shooting off hand, or with minimal pressure on the handguard, i.e., you’re not bearing down on the handguard to form stability like one would with sling-assisted shooting, barricade shooting, or loading a bipod, then it probably doesn’t matter very much. Just resting your handguard on something should have pretty minimal POA/POI shift. Beyond that, if you’re not using the rifle in a duty manner, then it’s not a big deal to simply mount the pointer much further back on the handguard, which will minimize perceived deflection.
Otherwise, I would suggest looking at the various Hodge designs (WedgeLock variant, P-Lock, S-Lock, Drive Lock), Geissele (the older models having better rigidity than the newer models, e.g., MK8 vs MK16), Daniel Defense RIS (the III is coming out soon, you could always wait for that), Ripcord Industries LDR1, Griffin Industries RIGID series, Midwest Industries Night Fighter, and KAC URX4. Not an exhaustive list, and I do not personally vouch for anything on this list, just models to consider (I use a Hodge WedgeLock on my 11.5" that is my night gun).
No experience with them but how about one of these?
There will be a lot of bipod or offhand with sling shooting which is why I’m concerned about flex. I know the DD rails are freakin solid and I saw the RIS 3 is about to drop so I might be interested in that. Beyond that, this will double as a go to rifle for whatever hypothetical situation we can invent in our minds so I have duty thoughts in this as well and definitely want the laser mounted as far forward as possible. Plus I just hate having shadow in the illuminator.
With the force behind loading a bipod, you will likely see deflection with any non-monolithic handguard, particularly if it’s a longer handguard. I would also be wary of any POA/POI shifts that can occur in such a situation, even without a pointer in the mix; a friend of mine was able to consistently generate several MOA worth of shift when he loaded the bipod on his KAC LPR. While stiffer handguards will have less deflection, that doesn’t mean they will have no deflection; this is something that I was taught during my NODs class, the need to recognize when one was missing despite having a good sight picture and good trigger squeeze, and that deflection may be an issue, given the amount of force one can lever into a handguard, something that the instructor (Pressburg) had seen downrange.
I’m also mildly curious as to the use-case of regularly using a bipoded rifle with a pointer, rather than using a clip-on, if that level of precision will be needed.
Main reason for bipod use will be for some coyote stuff out of the bed of a truck, working on getting clip on sights but just dont have them yet. The bipod isn’t as big of a concern as I’m well aware of how much force is generated when loading a bipod. But bracing off of a truck or using a sling to stabilize is what will be happening most of the time so I want to make sure that those forces aren’t going to create a huge shift. The RIS 2 is probably the safest bet, as its proven and can double in a duty roll
The RHF handguard has much more shift than the DD and Geissele rails I’ve used. It’s kind of like comparing the most flex to the least flex outside of going monolithic. The BCM rails also flex quite a bit. I’d take a good look at the available G and DD rails and go from there. Midwest Industries makes a series of rails for this application which you can find at the following link: https://www.midwestindustriesinc.com/Night-Fighter-Handguards-s/602.htm
Saw the nightfighter handguards and they look pretty good. You know anyone who’s used them?
I don’t, but would like to try one.
I’m thinking about snagging one since the price is half what a DD is. If I get one I’ll post back up and let you know
Much appreciated. It definitely looks worth a try.
SOLGW M89
i don’t think i can really add much to this post as i don’t have NV so no experience with shift on lasers. I have done test with irons and of the handguards i have used (DD MFR MLOK, BCM QRF, BCM MCMR, Geissele MK8, Geissele Mk14, LT quad, LT LAT, a VLTOR Freedom MLOK). most were 13 or 13.5" but the MCMR was 15", the LAT was 12" and three MK8 (10.5, 13, and 13.5). top choices after zero then load on a bipod and shoot prone were both Larue’s, MK8s, vltor freedom rail. next up was the QRF 12 and Mk14. last was the 15’ MCMR. i still like the MCMR but that long rail did notice impact shift. I no longer have that handugard on that rifle and wish i did as i did a following test below (that is not scientific but caught my interest when i found the results).
take this with a grain of salt
at my local gun shop about 6 months ago, they had 3 identical rifles (in barrel length and handguard length) all were mlok
G super duty 16" barrel 15" mk16 handguard (surefire CTN)
BCM 16" BFH with 15" mcmr handguard (cant remember what comp it had but it was BCMs)
DD V7 16" barrel with 15" MFR mlok (DD’s flash hider)
I took them down and with my thumb and index flinger tried to pinch the barrel to the handguard at the shoulder of the MD. not with much pressure as i didn’t want to mess up any rifle. to my amazement the GMK16 rail i could almost get it to touch with very little pressure. it felt spongy at the connection with the upper, barrel and barrel nut. the other two i couldn’t really budge them at all and i said that BCMs was the winner as i think i moved slightly less than the DD. but it took me several times to figure that out as it was close between those two. Something could of been wrong with that rifle and i kind of think there was.
I have found the geissele mk8 to be very stiff and solid.
SOLGW, Hodge, KAC, LMT monolithic.
I’ve got one built onto an upper sitting about 10’ away from me. There isn’t much doubt it is a solid rail. That doesn’t mean there aren’t other solid rails, it simply means this one was designed for the task of which you speak.
Great to know.
Rails I have personal experience with and can recommend:
Picatinny: DDM4 and Larue. DDM4 is lighter and more expensive. I’m not sure if it could be used as a club or not, but neither of mine show much flex in normal use, or when finger-fooking them. I’ve got a 12” and a 10”. Larue is a brick shithouse and is what I’d most recommend for a Pic rail. Anything that makes it lose zero will kill the laser and/or user. I’ve got an 11”. Both of those rails have similar, but smaller profiles than the RISII (I own a 12”). The Centurion C4 has a very different profile, but is also good and will hold zero and flex very little. I use a middy FSB cutout one. I use 5 uppers with all 4 of these with a LAM and am happy with them. https://www.m4carbine.net/showthread.php?229872-Cheese-Graters-2021
MLok: Geissele Mk8 (thicc), KAC URX4 and Larue LAT (Goldilocks), Hodge, SOLGW, and Triarc Wedge-Lok (anorexic). Of these, the one I like most is the URX4. I’ve got a few of these, and one has been used extensively with LAMs. Its a 10.75”, but I’ve used or have every length but the 8.5”. Its probably the lightest handguard that I’d recommend for lasers. The Wedgelock is stout, but there’s not much to hold onto after you mount a light and laser. Dudes that use vert grips or have small hands will like them more than I do. I have a 7”, but it doesn’t really see much use. The G Mk16 handguards are fine on a 11.5” barrel, but skinny like a Wedgelok. I have too little experience with the longer ones to give much advice, but I have a buddy with a 16” Super Duty and a DBAL D2, and he’s happy. He shoots it weekly and its his main squeeze.
SBRs will show less flex than, say, a bipod gun with a skinny 15” handguard. I haven’t tried the new MI one.