Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 40

Thread: AR15 Optimal Rail Length Discussion / Fixed FSB

  1. #11
    Quote Originally Posted by OlongJohnson View Post
    I see no point in hanging more rail weight off the front of the gun than you need rail space to run it and hang stuff.
    Kind of piggybacking off Wake's post. Reasons for longer rail/handguard which covers more barrel:

    1) Less deflection when shooting off cover/barricade;

    2) More room to stretch out your support arm for faster transitioning and comfort; most guys don't shoot that whippy grabbing the mag well or the carbine length handguards, longer is optimal;

    3) Less chance of burning yourself on the barrel when shooting from suboptimal positions;

    4) Aesthetics - even without the above advantages, I prefer the longer rails.

  2. #12
    Is it ever a good idea to have the rail be flush with the end of the barrel’s flash hider/muzzle brake?

    I’d be afraid of grabbing the rail too far down, near the end, and hot gas burning me.

    I assume this is always a bad idea but I thought I saw someone doing that with a really shorty barrel.

    And if this is sometimes a good idea, any way to mount a silencer/suppressor on the end? I assume the rail would be too cramped to access the silencer’s locking lever thingie.

    I’m wondering if maybe this could work for a dedicated suppressor host gun, I’m thinking about a 9” barrel 300 blackout. There’s virtually no 8” rails, so you need to use a 7” rail which is kind of short. I wonder if you could get a 9” rail on a 9” barrel and maybe grind off some of the end to make room for your fingers to push in the suppressor release lever. Or if it’s going to be run suppressed all of the time, maybe fine if you can actuate that lever with a punch through a hole in the rail for cleaning on occasion. Or maybe can just clean it with the barrel attached.

  3. #13
    The only time I can think a rail being flush/beyond the muzzle threading might be acceptable or even a good idea is 1) dedicated suppressor host run as basically integral suppressor, or 2) non-suppressed with a blast can style linear comp that protrudes beyond the rail. Any other set up that has a muzzle device inside the rail will be a recipe for rail damage and/or hand placement errors.

    Personal taste- I like rails in the 10-13" ballpark depending on barrel length. Anything longer than 13" and I'm not doing anything with the extra length so it's an aesthetic choice. Although my 11.5" barreled uppers have 10-10.5" rails, everything else has a bit more barrel protrusion. I like being able to fit the barrel through small ports (situation dependent, but think VTAC slits), which can be tricky with rails and accessories that come close to the muzzle.
    Anything I post is my opinion alone as a private citizen.

  4. #14
    Site Supporter rob_s's Avatar
    Join Date
    Nov 2011
    Location
    SE FL
    I prefer more barrel exposed than most others do these days. Particularly on 16” barrels. I get no real advantage of a 15in rail over a 13in and I like having a narrower profile nearer the muzzle for jamming the barrel into things.

    So I would prefer this upper
    Name:  A670B26D-33CC-46B0-A494-E3F07F51D81E.jpeg
Views: 169
Size:  60.2 KB

    To this one
    Name:  1402ABDC-3790-487F-8823-C678863B94DA.jpg
Views: 169
Size:  15.1 KB


    I suppose I should also say, having previously been a big fan of barrel-mounted fixed front sights, I’m not really in that camp anymore. Exposed barrel or no, I’d rather have the hand guard space than the fixed FSB. I *do* like a locking, metal, set of folding BUIS with a “same plane” rear aperture and and absolute cowitness red-dot. I’ve seen arguments for non-locking, spring-held, BUIS in that they bend not break, and then I’ve seen them get dirty or worn and get knocked and not return fully, or not deploy fully at all. Or deploy by accident. I’d prefer to manually deploy the sight(s) and have them lock in place once deployed. I also prefer a non-QD RDS mount and I still prefer a 30mm Aimpoint to a micro.
    Does the above offend? If you have paid to be here, you can click here to put it in context.

  5. #15
    Member gato naranja's Avatar
    Join Date
    Dec 2018
    Location
    Flyover country... and never too far from the food bowl.
    We had a DD M4v9LW here that was purchased partly because that 15" rail would allow a BUIS front sight to be WA-A-A-A-AY out there, not for the normal reason of increased sight radius for "accuracy," but because the thought was that my visual accomodation issues would make the front easier to see the further forward it was. That theory did work out to the extent that it could.

    A minor additional reason was that the weaponlight could be far enough forward that the barrel/FH would interfere less with the light. This, too, did work out, though not so importantly as to jump up and kick a cat in the 'nads.

    Thirdly, the plan was to eventually go with an optic of some sort, and it was thought that the added real estate might be a good idea if anything else (think "laser" or "IR" or whatever) went on board. Better to have rail and not need it than to need it and not have it, so to speak.

    (The logic for Picatinny vs M-LOK vs KeyMod vas convoluted, but Pic rail won by a nose at the time. It still would if we were to do it all over.)

    In a nutshell, the rig was very competent, very docile and only a bit heavier than any other 16" middy of comparable barrel contour, with the eventual optic and mount being far bigger tubs of lard than that long quad rail. Was it optimal? I never did figure that out, but I can say that there really didn't seem to be many downsides; it was a lot harder to burn a hand on it than on any carbine with a short rail, and I liked how I could get my hand way the hell out there and "drive" that thing.
    gn

    (un VIEJO gato naranja... and still skeptical about humans)

  6. #16
    I have one 15” rail on a 16” barrel and at first I thought I was gonna swap all my other 13” rails but after using it for 3 years now, i think I like the 13”/16” better.

    I started off with a DD A1.5 fixed sight way out there and had a light mounted behind it. Wound up sticking the sight behind the light just worked better with my set up. A longer rail will at least theoretically have more flex and that doesn’t work with a rail mounted sight.

    My hand placement was the same on the 15” rail as the 13” rail. Shooting off a barricade I find my gun moves less with my hand as a cushion so the extra rail wasn’t really necessary.

    I do have one carbine gassed gun with the A2 sight and frankly, there is no rail system that works better tha Magpul SL hand guards. If I had a mid length I might look at a cut out rail but I just shaved the FSB on my other carbine and stuck a sight on the 13” rail. Actually I used a Troy rail with the built in flip up sight.

    Just the way I did it.

  7. #17
    13” is about where the utility ends for me as well. I’m 5’7” and just can’t really reach anything mounted at the wnd of a 15” rail and still be able to move around.

    Clearing multi-level structures has showed that I need my light a little bit closer.

  8. #18
    A 13.5" rail is max for me. and I set up my VFG/light so my support hand is in the same spot that my hand would be if I ran a pistol. I'm not fully extended/locked elbows shooting pistol, and I keep my torso position the same when running a rifle

    I sued to keep flip ups on the rifles, and I'd use them every time, but only to verify that my optic hasn't had a zero shift. I flip them up, confirm that the dot is where is should be, then flip them down. Now that I've gone to 1.93"-2.26" optic heights, the irons are useless

  9. #19
    Quote Originally Posted by M2CattleCo View Post
    13” is about where the utility ends for me as well. I’m 5’7” and just can’t really reach anything mounted at the wnd of a 15” rail and still be able to move around.

    Clearing multi-level structures has showed that I need my light a little bit closer.
    This is an area where one size obviously doesn't fit all, I'm 6' with a 36/37" sleeve length, I prefer a 14 to 15" rail over a 13" rail.

  10. #20
    Site Supporter rob_s's Avatar
    Join Date
    Nov 2011
    Location
    SE FL
    Quote Originally Posted by Dan Lehr View Post
    This is an area where one size obviously doesn't fit all, I'm 6' with a 36/37" sleeve length, I prefer a 14 to 15" rail over a 13" rail.
    for sure.

    I'm slightly taller/longer than you can I'm 13" rail all day long.
    Does the above offend? If you have paid to be here, you can click here to put it in context.

User Tag List

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •