12G Shotshell - Subsonic Vs Supersonic?

Discussion in 'The Ammo & Reloading Forum' started by Godzilla187, Jan 24, 2018.

  1. Godzilla187

    Godzilla187 New Member

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    Hi,

    This post is in regards to 12 Gauge Shotshells.

    I was reading this article:

    https://www.americanrifleman.org/articles/2015/6/19/subsonic-shotshells/

    It was talking about subsonic/supersonic shotshells for defensive/hunting purposes.

    What's the difference between subsonic & supersonic shotshells?

    Does barrel length play a factor in a quieter shotshell?

    It said shotshells that are under 1116 fps don't break the sound barrier (subsonic):

    "The speed of sound at sea level and 59° F. is listed at 1116 feet per second (fps). And even though the speed of sound isn’t constant, changes in altitude and temperature, among other factors, can affect that number. Breaking that threshold means the difference between producing a hearty fooop sound and an earsplitting boom..."

    As far as an effective subsonic 12 gauge shotshell, it said:

    "Consider this: 12.0 grs. of Hodgdon TiteWad propellant in a primed 12-ga., 2¾” Cheddite hull propels a Ballistic Products, Inc., 1 1/8-oz. lead, hollow-point Thug-Slug to 856 fps. from an 18½” barrel. Seems unconvincing, right? At that velocity, the 492.2-gr. slug packs 800 ft.-lbs. of energy, which is about double the energy produced by the much-vaunted 10 mm and more than most 240-gr. .44 Mag loads. Would anyone deem the .44 Mag. as being inadequate for personal protection? Not likely. And, even before expansion, the hulking chunk of lead is 0.725” (+/-) in diameter. Use 14.0 grs. of TiteWad and the velocity increases to 1020 fps, resulting in 1,137 ft.-lbs. of energy..."

    Is supersonic just another name for a fast moving shotshell (or round) like the Winchester XPS @ 2000 fps:

    https://www.sportsmansguide.com/pro...ster-xp3-slugs-12-gauge-3-300-grain?a=1592563



    Your time is appreciated,
    Godzilla187
     
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  2. LIKTOSHOOT

    LIKTOSHOOT No Power Options Supporting Member

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    I cannot speak to the sound difference between a 2 3/4" to a 3" and can tell you a .12 gauge is not quiet in any way.
    The 2 3/4" `s we used for hogs, we used 3 different makers only because of slug designs. These sabot`s ranged from 1650 to 1850fps and were a stout recoil.
    Remington 870 with a 20" rifled barrel. Felt like a semi-auto because the recoil would cause the slide/pump to release after firing and the reaction would be to push the slide forward making for fast follow up`s.

    Yes barrel length effect`s sound.....shorter is louder in any application.
    Because you have a bigger bore it allows the gasses to escape as any other big bore rifle.
    The super sonic crack is minimal compared to the blast.
    The slugs some of my friends used were about 1200fps and at that time were labeled "Reduced Recoil" They were much softer to shoot.......mostly for recoil shy shooters.
    The 2 3/4" was stout at 1850fps with copper sabot solids, I did try the 3" and for the small gain of 150fps was simply not worth the punishment as we shot quite a lot in any outing for hogs.


    It later years we used the 7.62x39 on the AR and AK platforms as it allow much less recoil and faster follow ups AND more round count. When we pushed up large groups the round count allowed for more hits and hogs.
    We never used anything but copper solids in the .12ga.
    Quiet and .12ga does not come with quiet even at sub-sonic levels.
    "No animals were harmed during this writing"
     

  3. The_Rifleman

    The_Rifleman Well-Known Member

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    I can't stand to read some of those writers, they need something new to write about, and pick the most ridiculous topics.
     
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  4. Godzilla187

    Godzilla187 New Member

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    Thank you for the information and the detailed response!

    So, Bottom line, a 12 gauge subsonic shotshell is gimmick? They still break the sound barrier causing a loud boom?

    I found this link which added some helpful information on the topic above:

    http://www.shotgunworld.com/bbs/viewtopic.php?t=246514
     
    Last edited by a moderator: Jan 25, 2018
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  5. The_Rifleman

    The_Rifleman Well-Known Member

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    Here is what a "ballistic crack" from a shotgun sounds like.



    It isn't happening like you think.
     
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  6. carver

    carver Well-Known Member Supporting Member

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    Subsonic = below the speed of sound.

    Supersonic = above the speed of sound.

    Supersonic is just louder than subsonic. But it's hard to tell the difference with just the human ear. They are both loud!