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AR 300AAC or 5.7

Discussion in 'Rifle Country' started by fpjeepy05, Nov 13, 2012.

  1. fpjeepy05

    fpjeepy05 Member

    With the election of our new president I've decided to get an AR. I have plenty of bolt and single shot rifles, but I want something I that in an event that I need to "spay" some bullets I can do so.
    I've got a TC Contender Rifle chambered in 300 Blackout. And once my paperwork goes through I'm planning on getting a FNH Five Seven for a concealed carry.
    That being said I would like to get an AR chambered in one of these so that the ammunition and/or cans are interchangeable.
    I like the 5.7 because its got the 50rd mag.
    Easier to get subsonic ammo for the 300
    Ammo is about the same $22-24/box of 50 for the 5.7 and $30-32 /50 for the 300
    I'd like to get a bumpfire stock eventually and I believe that would only be available for a AR-15, which would mean 300.

    Anyone else that some thoughts.
  2. billphoto

    billphoto Member

    No doubt between the 2, 300 Blackout. Ballistically superior, better anti personnel, easy conversion from 5.56. Plus if 50 rnd mags are your thing, get a surefire 60. 5.7 is nothing more than a hyped-up 22 magnum. The only projectile that gives the 5.7 it’s glitz are the ones designed to defeat body armor and you can’t buy those.
  3. barnbwt

    barnbwt Well-Known Member

    What happened to the old one :confused:;)

    If you are interested in suppression (300BLK + sub sonic ammo; I'm guessing you are) then the 5.7 really loses its allure. If you want a "quiet" gun for home defense, I'd suggest looking into a lower-pressure larger bore carbine in a pistol caliber. There is a cool (looking) AR57 with a short barrel and suppressor built into the forearm; very cool, but probably useless with 40gr subsonic ammo :D

    I love my Five-seveN, but it is a tad large for daily use unless OC or unintentional printing is kosher in your locale. Maybe you hide a big gun better than me, though :)

    I've heard the PS90's are awesome (on my short list), and that the AR57, while the most novel application of that platform, is very reliable. Definitely the most affordable way to get into the 5.7 racket.

    And by "racket" I mean the round is noisy. You'll want muffs if you intend to use it for defense or even hunting/plinking for sure. I guess what I'm saying is you need to make a choice as to which end of the spectrum you'd like to go; big n slow (300blk) or light, fast, hi-cap. Very different operations. I have heard (do not take this as gospel) that 5.7 out of a rifle length barrel fragments into nothing when it hits interior walls, making it a bit less threatening to bystanders than a slow 7.62 slug or 00 buckshot. A Five-seveN pistol shot will go straight through sheetrock walls with ease, though.

    Even with as little recoil as a Five-seveN, spraying still doesn't do anything but waste ammo and endanger others. I still need to take my time like any other gun for the bullet to go where I want it :)

    In any event, if you are stocking up, budget just as much money for ammo. 5.7x28 was nigh unavailable not two months ago and only recently is showing up again (at .10$ extra a bullet). I imagine 300BLK is much the same.

  4. aubie515

    aubie515 Well-Known Member

    There is a lot of fail in this reply. Disregard as the poster probably never owned or fired either caliber.

    I've owned everything that was offered in 5.7...from PS90, FsN and AR57. It's a neat caliber and I too liked the idea of having 50rd mags because your mag change would be nearly a 2:1 ratio.

    I sold everything in 5.7 and really regret selling my PS90...that rifle fits me so well and I'm considering picking up another one. If you get the PS90 or the AR57...the neat thing is you can remove follower/spring in a standard AR15 30rd mag and use it as a brass catcher. You can buy or DIY brass catcher for the PS90.

    I've owned the KT PMR and FsN and I can tell you that 5.7 is NOT a gloried 22 mag. Take a look at velocities from Elite Ammunition and compare it to 22mag velocities.

    There is a lot of myths floating around about the 5.7 and most of them are untrue.

    I am building my first 300BO bolt action because I'm going to be using it for suppressor work and I don't think you can go wrong with that caliber either.
  5. MachIVshooter

    MachIVshooter Well-Known Member

    .300 BLK makes more sense.

    The P90 PDW, a super-compact, light weight PDW with armor piercing rounds and a very high ROF is a useful tool. The lengthened semi-auto PS90 or the even longer AR57 with their semi-auto only mode of operation and neutered ammunition are just a novelty. If you're going to have something the size of an AR, it might as well pack the punch of 5.56 NATO or some other chambering that utilizes the action's length.

    If it's about the capacity, 5.56 mags have it all over the 5.7.

    60 round Surefires that are barely longer than a 30 rounder:


    90 round snail drums:


    100 round Surefires for a slender profile:


    Or 100 round Beta-C if you don't want it hanging down:


    I have a Beta-C, and it's fun. However, from a practical/economical standpoint, a pair of $10 Pmags with a $15 coupler makes a lot more sense than any of the hi cap stuff.

    And both still pea shooters. The hottest loads from EA barely muster 9x19mm performance (and at > $1/shot to boot).

    I have a PMR-30, and it's a blast. The Five-seveN is fun, too. But I'll leave the serious work to serious cartridges.
  6. Walkalong

    Walkalong Moderator

    I have had both, and I still have my .300 BLK. Easier to load for if you reload, superior ballistics, just as much fun, very versatile, no unique parts from a .223 AR, only a barrel change, all other parts can be used....

    The 5.7 is a neat little round though.
  7. highlander 5

    highlander 5 Well-Known Member

    From a reloading stand point,the 300 is the best bet. If you can't get 300 BLK brass you can always make it from 17 Rem Fireball,17 Rem,221 Fireball,204 Ruger,222 Rem,223/5.56 or 222 mag brass. 5.7 you're stuck with factory brass and from what I've heard it's a finicky round to reload for. My oppinion on the 5.7,just a rimless version of the standard 22 Hornet round.
  8. barnbwt

    barnbwt Well-Known Member

    Jeez, already?:rolleyes::banghead: Might as well lock this one now, mods, before more velocity stats, wound photos, and gelatin cross-sections get posted :banghead:.

    Please allow me a quick defense of a wrongly-maligned chambering:
    As far as .22WMR comparisons, no contest. Power aside, 5.7 has a more reliable igniting&feeding centerfire cartridge, and much better bullet construction out of the gate. I've seen a fair number of .22WMR duds/jams in the trashcan at the range, but I've never even heard of a dud round in 5.7 from FNH. It was only rejected by NATO due to lobbying from competitor H&K and re-armament cost to member countries, so it's hardly ill-suited for defense. The only thing to hate about 5.7 is the cost of the rounds and its platforms (from FNH, at least). Many say it is impractical and therefore stupid/wrong. Yet I see little hate on 375H&H magnums and other similarly "impractical" rounds. No, 5.7 ain't the be-all end-all; but no one says that (and I doubt anyone but FNH's marketing team ever did). I believe 5.7 comes in just under 22 Hornet, but with a bit less recoil--don't quote me on that, though

    Back on target:
    Reloading: big win for the 300, since it can be feasibly/economically done
    Use: again, the 300. From a semi-auto rifle, recoil is a non-issue in both, and the lower pressure of 300BLK will make shooting much more enjoyable
    Suppression: a sub-sonic 5.7 is retarded in my book (literally and figuratively). Buy a suppress 22LR for way less money
    Best for a utility rifle: Neither. If you are worried about cost, any standard calber will quickly recoup the cost you would save through commonality in your guns. If you must choose one or the other in an AR, go with the 300; it's way better for suppression and designed for ARs

  9. meanmrmustard

    meanmrmustard Well-Known Member

  10. Warp

    Warp Well-Known Member

    All of the reading I have done indicates that none of the magazines over 30 rounds are bet-your-life reliable. The 30 round PMAGs and USGI magazines, however, are.
  11. MachIVshooter

    MachIVshooter Well-Known Member

    Allegedly, the Surefire 60 rounders are stone axe reliable now.

    I would trust the Beta-C. Mine has never induced a malfunction in an AR or my PLR-16. There's a reason they cost $250.
  12. fpjeepy05

    fpjeepy05 Member

    I'm leaning towards the 5.7. I like the unique feed mechanism on the AR57. And I think that it is plenty powerful enough.

    .223 68grs out of a 16" Barrel ~2590fps
    5.7x28 40grs out of 16" Barrel~2538fps
    22 WM 40gr out of 16" Barrel ~1900fps

    I know data points can make things look however you want them to, but I think the 5.7 bridges the gap between the 22wm and the .223 pretty well.
  13. justice06rr

    justice06rr Well-Known Member

    I've never owned a 5.7, but have 300BLK and 5.56 AR's.

    The 300BLK AR would make the most sense for the OP's purposes. Mag cap issues are no problem with 60, 100, and drum mags. Better interchangeability with any AR part save the barrel, supersonic/subsonic ammo, and easier reloading are the big advantages of the 300Blackout.

    I see it this way, the 300BLK is a reliable 7.62caliber solution to the AR15 platform. Basically an AK round that works very well in a standard AR.
  14. Pete D.

    Pete D. Well-Known Member


    Here' what I don't understand....you are going to get an AR. OK, good....but you are going to buy it chambered for one of two rather esoteric cartridges, both of which are less available than .223, more expensive, not terribly different in power ( The 5.7 decidedly less powerful at all ranges. The 300/7.62x35...kinda like the 7.62x39, certainly not much different energy wise than the .223), and available in fewer loadings.
    Why would you want to do that?
    What is wrong with .223/5.56 that you would choose two cartridges that present more logistical problems (at least logistical...not to mention performance)? Of course, you can always have two uppers.
    Last edited: Nov 15, 2012

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