Preferred AR-15 SBR Barrel Length?

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  • sloppyjoe

    Sharpshooter
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    Mar 27, 2019
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    Brownsburg
    The entire process of getting a SBR is a logistical nightmare. I hate the stupid governments rules, and waiting 8 months or more for a stamp. That's why I only have one SBR. That being the case, going with one that's only a little bit shorter like a 13.7 or 14.5 makes zero sense in my book. (unless you're gonna pin & weld the flash suppressor to make it legal without the stamp) If you are going to the trouble of getting the stamp for the small package, get the small package. I went 10.5".

    You only have to SBR one lower, and then you can use it with multiple uppers of different lengths and calibers.
     

    hpclayto

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    22   0   1
    Nov 8, 2008
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    The entire process of getting a SBR is a logistical nightmare. I hate the stupid governments rules, and waiting 8 months or more for a stamp. That's why I only have one SBR. That being the case, going with one that's only a little bit shorter like a 13.7 or 14.5 makes zero sense in my book. (unless you're gonna pin & weld the flash suppressor to make it legal without the stamp) If you are going to the trouble of getting the stamp for the small package, get the small package. I went 10.5".

    I got mine back in 8 days. It was super simple.
     

    MRE Milkshake

    Plinker
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    0   0   0
    Apr 24, 2022
    56
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    Indianapolis
    Length and accuracy aren't a direct correlation. Length most directly effects velocity. An accurate barrel is more based on the quality of manufacturing. I lean towards Criterion Barrels. Ballistic Advantage Hanson barrels are good quality for the price. I think a taper profile is the way to go.

    But yes... a quality 11.5 will be plenty accurate. But so will a quality 10.5. You just lose velocity with the 10.5 so you're going to have a more drop to compensate for when going out past 200yds.

    I felt like my 10.5" was rough on components. I think over time you would see more wear and tear on a 10.5 over an 11.5 due to the shorter dwell time.




    Gotcha, good to know. Thanks for the videos!
     

    MRE Milkshake

    Plinker
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    0   0   0
    Apr 24, 2022
    56
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    Indianapolis
    My experience for what it's worth...

    The suppressed 10.5 was noticeably louder than the same suppressor on a 13.7.

    10.5 is just really loud in general. Personally, I would go either 11.5 or 12.5. History shows the military tested several different lengths back in the 60s and come to prefer the 11.5 over the 10.5.

    I own a 14.5 and its not nearly as loud and concussive as the shorter lengths ive fired. So I think an in between would make sense.
    Thoughts between choosing 14.5 or 11.5?
     

    MRE Milkshake

    Plinker
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    Apr 24, 2022
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    Indianapolis
    I have both and really enjoy shooting both. I don't think you can really go wrong with either.

    I live in the suburbs, so if I needed to grab one as a neighborhood patrol rifle I could use either since likely engagement distances are going to almost always be under 200 yards. It's nice having the option of something shorter if there is a possibility of being in a vehicle. But we're talking like SHTF type scenarios, and those are unlikely.

    The 14.5" in the pic I posted above now has a 1x8 LPVO on it which is nice for target identification over a red dot. I have used it to make hits out beyond 500 yards, but I rarely have the opportunity to shoot at those distances.

    I guess it boils down to one's personal preference and situation. People talk about losing velocity with a shorter barrel, but that's not an issue when a majority of the shooting I do is 50 yards or less. That said, if I could only have one it would be the 14.5" just because it is more versatile. The extra few inches adds more versatility at longer distances and gives up very little in terms of weight and maneuverability.
    Gotcha, good stuff to take note of. Thanks for the advice!
     

    hpclayto

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    Damn, how'd you get it back in 8 days? That seems insanely quick compared to what a lot of people on the internet have been talking about.

    Nothing special. Just Eform 1. They’re coming back quick, form 1’s not so much form 4’s, according to the interwebs. I followed national gun trusts video when filling it out.
     

    Nicu757

    Marksman
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    Sep 2, 2013
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    Brownsburg
    Another option. Get a sbr 8.0 300. Then buy a 10.5 pistol. Then you can interchange them. You can’t go lower but can go higher.
     

    Squid556

    Expert
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    11   0   0
    Feb 26, 2022
    975
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    Wabash Co.
    Thoughts between choosing 14.5 or 11.5?
    In my opinion, 14.5 is ideal for an unsupressed handy rifle / pistol. Useful out to 400 yards

    11.5 would be ideal for suppressed pistol use out to 250. There are some serious gains when the barrels are so short. Then they become less and less as it gets longer.
    A55C2AFD-F1E1-4FD7-BC30-3B68EF313A26.jpeg
    I’m sure someone will argue that you can hit farther than 400 and 250. And certainly you can, that’s just a number of effective range I’d personally put on them from what I’ve learned / experienced.
    Thoughts between choosing 14.5 or 11.5?
     

    yote hunter

    Grandmaster
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    Dec 27, 2013
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    Not sure what’s up with the 10.5 love ?
    But 7.5 in 5.56 works fine from what I have seen.
    I would believe a 7.5 in a home would work easier then 10.5 !? :twocents:
     

    MRE Milkshake

    Plinker
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    Apr 24, 2022
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    Indianapolis
    In my opinion, 14.5 is ideal for an unsupressed handy rifle / pistol. Useful out to 400 yards

    11.5 would be ideal for suppressed pistol use out to 250. There are some serious gains when the barrels are so short. Then they become less and less as it gets longer.
    View attachment 197779
    I’m sure someone will argue that you can hit farther than 400 and 250. And certainly you can, that’s just a number of effective range I’d personally put on them from what I’ve learned / experienced.
    Thoughts between choosing 14.5 or 11.5?
    Wow I never knew that the difference between 11.5 and 14.5 was fairly minimal in terms of velocity. Yeah it's roughly a 200 fps difference but considering the barrels are 3 inches apart in length I find that interesting.
     

    Squid556

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    Wow I never knew that the difference between 11.5 and 14.5 was fairly minimal in terms of velocity. Yeah it's roughly a 200 fps difference but considering the barrels are 3 inches apart in length I find that interesting.
    To put that in more practical terms, when the military was testing the 55 gr M193 load, its primary means of wounding is what is called "explosive wounding". Which is when the bullet is traveling so fast upon impact that it comes apart rapidly causing massive tissue disruption. The threshold for explosive wounding is around 2500 fps. Anything less is surely lethal, but tends to poke holes and is less of an energy dump.

    They found the M16 with a 20 inch barrel lost explosive wounding past 170 yards. The M4 carbine with its 14.5 lost explosive wounding past 120. And the Mk18 with its 10.5 lost explosive wounding around 50 yards.
    downloadfile.jpg

    This doesn't mean that a 10.5 is useless past 50. Rather this is real world data that gives us a better grasp of what the tools are doing and how to best employ them for the jobs we ask of them.
     
    Last edited:

    Hop

    Grandmaster
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    Jan 21, 2008
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    I won't SBR another rifle lower when pistol braces are still available. Other than a greater length of pull on the SBR, I don't see a need unless you run a suppressor.

    I have/had:
    8" 300BLK
    10.3" 5.56mm
    11.5" 5.56mm
    14.5" 5.56mm (blind pinned & welded to 16")

    I had a problem with unburned powder building up on the crown of the DD MK18 10.3". The more I shot without scraping off the buildup, the more ammo sensitive it became. When clean & using good ammo, it was easily sub MOA.

    The 11.5" has made great hits out to ~500-550 yds. with MK262.
    The 14.5" Colt groups turn to crap at 400 yds, but it hasn't eaten good ammo yet, only M855.
     

    MRE Milkshake

    Plinker
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    0   0   0
    Apr 24, 2022
    56
    18
    Indianapolis
    To put that in more practical terms, when the military was testing the 55 gr M193 load, its primary means of wounding is what is called "explosive wounding". Which is when the bullet is traveling so fast upon impact that it comes apart rapidly causing massive tissue disruption. The threshold for explosive wounding is around 2500 fps. Anything less is surely lethal, but tends to poke holes and is less of an energy dump.

    They found the M16 with a 20 inch barrel lost explosive wounding past 170 yards. The M4 carbine with its 14.5 lost explosive wounding past 120. And the Mk18 with its 10.5 lost explosive wounding around 50 yards.
    View attachment 197820

    This doesn't mean that a 10.5 is useless past 50. Rather this is real world data that gives us a better grasp of what the tools are doing and how to best employ them for the jobs we ask of them.
    That makes sense. That does reinforce the point of choosing the right tool for the right job.
     

    Squid556

    Expert
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    11   0   0
    Feb 26, 2022
    975
    93
    Wabash Co.
    I won't SBR another rifle lower when pistol braces are still available. Other than a greater length of pull on the SBR, I don't see a need unless you run a suppressor.

    I have/had:
    8" 300BLK
    10.3" 5.56mm
    11.5" 5.56mm
    14.5" 5.56mm (blind pinned & welded to 16")

    I had a problem with unburned powder building up on the crown of the DD MK18 10.3". The more I shot without scraping off the buildup, the more ammo sensitive it became. When clean & using good ammo, it was easily sub MOA.

    The 11.5" has made great hits out to ~500-550 yds. with MK262.
    The 14.5" Colt groups turn to crap at 400 yds, but it hasn't eaten good ammo yet, only M855.
    “Mk 262”

    Gives me that warm fuzzy feeling inside.

    I’ve been buying the Frontier 75 which is Lake City loaded hornady bullets. Then I’ve been hand loading the same thing on a compressed Varget load. Hand loads shoot better of course but the frontier I’ve shot so far seems good.
     

    breakingcontact

    Expert
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    3   1   0
    Mar 7, 2018
    1,379
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    Southern Indiana
    I have a BCM 11.5" and it's the bee's knees. Sweet shooter and very flat. I don't personally find the noise all the bad when shooting it, but it's got some thump if you're standing next to it.

    I would NOT want to use it in a home defense role without a can on it. Shooting indoors with no ear pro would not be enjoyable to say the least.

    View attachment 197654
    556 I'd say 11.5

    300 Blackout, whatevs
     

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