Shotgun range/shot drop

Discussion in 'General Shotgun Discussion' started by RJF22553, Oct 20, 2020.

  1. RJF22553

    RJF22553 Well-Known Member

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    Hi, folks. This may be, perhaps a dumb question, but I am a novice at most things shotgun.

    Background:
    Of all my firearms, there is but one shotgun - a Mossberg 930 with two interchangeable barrels. I bought it exclusively for home/farm defense (don't hunt) and got 250 rounds of 12g 00 Buck.

    Of late, I've been pondering "what if an Antifa crowd with torches and molotovs bypassed my No Trespassing signs and began marching toward either my home or my barn complex???". The gate to my property (technically my property extends beyond the gate a bit) is about 800' from our home and about 600' from our barn complex.

    I have long guns (5.56mm/.223 REM) with sufficient effective range to shoot at individual targets with deadly force. The downside (other than legalities) is the possibility of an over-shot or miss that could impact a neighbor's home 1800-2000' distant.

    What I am considering is using the Mossy (with its 16.5" barrel) with standard 00 Buck ammo. No choke. It would - in effect - be an "area weapon" at <=800'. I don't expect (or desire) tight shot grouping and would prefer mostly discouraging a group from staying or further advancing on my property. At an 800' range I suspect 00 Buck would not be particularly lethal but sufficiently dangerous and injurious enough to discourage sticking around. Also, misses/overshots would be very unlikely to cause damage or danger to my neighbor's house (or even reach it).

    Question:
    I know the shot spread would be very wide, but am at a loss as to how much drop at 800' I should correct for.

    Thanks in advance. I have ballistics tables and drop info for 5.56, .223, and .30 Carbine, but haven't found any info for shotguns firing 00 Buck.
     
  2. G66enigma

    G66enigma Well-Known Member Supporter

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    The JBM Ballistics web page ought to be able to calculate it.

    Haven't seen estimates for ballistic coefficient (BC) for .12.ga shot. Have used various 00 Buck shells with velocities in the 1200-1300fps range. With rough estimates assuming a BC of 0.15, velocity of 1300fps, 300gr of shot, range of 300yds and increments of every 25yds, the following table is calculated:

    Calculated Table
    Range Drop Drop Velocity Energy
    (yd) (in) (MOA) (ft/s) (ft•lbs)
    0 -1.5 *** 1311.4 1145.4
    25 -0.0 -0.1 1230.4 1008.3
    50 -0.0 -0.0 1160.5 896.9
    75 -1.6 -2.0 1101.9 808.7
    100 -4.9 -4.7 1053.6 739.4
    125 -10.3 -7.8 1013.3 683.9
    150 -17.7 -11.3 978.8 638.1
    175 -27.4 -15.0 948.5 599.2
    200 -39.5 -18.9 921.2 565.2
    225 -54.2 -23.0 896.3 535.0
    250 -71.6 -27.3 873.2 507.8
    275 -91.8 -31.9 851.6 483.0
    300 -115.1 -36.6 831.3 460.2

    ^ So, @ 250yds (close to 266yds = 800ft), it's ~71" drop.

    A very rough estimate, given unknown BC and unknown actual weight of shot in a given shell, but probably not all that far off the mark.
     
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  3. Chainfire

    Chainfire Well-Known Member Supporter

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    I live out in the country, but I haven't had any trouble with anti fascists. I don't care what their politics are if they are trespassing, they are going to get my attention, but not with a shotgun from 800 feet.
     
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  4. JTJ

    JTJ Well-Known Member Supporter

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    Unless you have an SBS your barrel is 18.5". 00 Buckshot is generally a 25 yard load. By 40 yards the pattern will be getting sparse. Might work for a group shot though. You can extend the range 10-15 yards with Federal Flight Control and Hornady Critical Defense. At 800' I would lobbing slugs if all I had was a shotgun. With a 50 yard zero you would have at least a 2' drop at 250 yards. You would be better off with rapid fire with the AR. I sight my AR at 50 yards and have 4"-6" hold over at 300 yards. Unless you are aiming very high the 5.56 will be in the dirt before it gets to your neighbors house.
     
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  5. RJF22553

    RJF22553 Well-Known Member

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    G66, T H A N K S ! ! ! :D Just what I was looking for!
     
  6. RJF22553

    RJF22553 Well-Known Member

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    JTJ, thanks for the correction: the 930 came with both an 18.5" and 26" (I think) barrel. Don't know what I was thinkin'...

    As far as aiming too high, the neighbor's house is a bit lower than ours and - in the heat of the moment - I don't want ANY possibility of hitting it with a lethal round. The terrain is such that should an unruly mob continue on, the prospects of them being in line with the neighbor's house diminishes.

    I would not be out there standing like Clint Eastwood, but rather likely in a prone position with a few 5.56 long guns by my side and a stack of mags, with my dead-eye wife providing overwatch similarly equipped and prepared to protect me and her horses. Just don't want it to get to that point if the shotgun encourages a "we'll be moving on now" response. If after five shots there is no appropriate response, then comes the 5.56 semi-autos and bolt gun. My immediate next-door neighbors would provide additional encouragement.

    I hope none of this ever happens, but "hope" is not a course of action...
     
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  7. Ghost1958

    Ghost1958 Well-Known Member

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    The type of mob with torches coming through a locked gate in a rural area is likely to be armed with more than torches. Nothing says a mob cant of wont have a few Ar s or the like in the mix
    One I'd hate to have to explain why I opened fire at a distance of 800 ft unless I was being shot at.
    2. By the time you have fired a couple of what are basically warning shots you'll likely come under REAL fire from rifles on the postion you just gave away. And even odds you wont live to touch the rifles beside you.

    The likely hood of a 556 round going 1800 feet and penetrating a house wall with enough energy to hurt anyone is tiny.
    Unless of course your using green tip LAP rounds. Though I dont know why you would be.

    Just some food for thought.
     
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  8. G66enigma

    G66enigma Well-Known Member Supporter

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    ^ This.

    Just from the standpoint of ft-lbf of force, though, 00 Buck seems to still have about the same punch at 250yds as 9mm rounds would. At roughly similar speeds, roughly similar hitting power.

    Though, as you suggest, it's really a sub-100yd cartridge. Even better, 50-75yds max. I wouldn't want to depend on it getting the job done much farther out than that, myself. Not on a two-legged predator who's very possibly (even likely) "armored" with some protection beyond his lily-livered felon skin.

    My own personal metric: If it can lop off a 2x2 post with a couple of rounds, it's still got enough hitting force to make me feel better. In my experience, that begins to get tough at about 35-40yds ... assuming I strike it clean. Fewer pellets, greater spread, less force. I'm sure a determined assailant's still going to be an unhappy camper beyond 50yds, if struck, but still.
     
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  9. G66enigma

    G66enigma Well-Known Member Supporter

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    There is that.

    Shooting out into the dark, simply because someone is there, gets hard to explain why it was so vital to be shooting at people. As you suggest, unless they're actually firing upon us, it's going to be a dicey claim to suggest death or dismemberment was imminent. Can't see many on a jury thinking that would be reasonable, no matter how slanted the jury in favor of self-defense acts.
     
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  10. SRK97

    SRK97 Well-Known Member Supporter

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    If I was going to shoot buckshot at long range, and was not too worried about killing what I hit I would use #4 buck (24 cal I believe). 27 pellets rather than 9.
     
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  11. RJF22553

    RJF22553 Well-Known Member

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    Well, I knew this would start some lively discussion!;);)

    I'm of the generation of "you use the tools you have...if all you have is a hammer,everything looks like a nail". This is by no means a "plan", but just trying to figure out the tools I have available and how they might be used.

    Need to sign off for now, my very friendly barn cat has decided my arms and keyboard are nice sleeping digs.

    Later. Thanks all for your input so far.
     
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  12. Double20

    Double20 Active Member

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    Unless I have misinterpreted the above, you are figuring this based on the total mass of the shot and not the mass of each individual pellet. Once the buckshot leaves the muzzle and the pellets start to separate, they act as individual projectiles at that point. Each pellet is acted upon by gravity and air resistance independent of the other pellets in the load. So to determine drop, you would have to figure for the weight of one pellet and BC of one pellet. The BC of a 00 buck pellet as far as I could find is about .071 and each pellet weighs somewhere between 55 grains and 60 grains depending on pure lead vs pellet with some antimony. Therefore, a 00 buck pellet with that weight and that BC is going to drop a lot further at 250 yards than what your calculations show unless I am misinterpreting them.
     
  13. Virginian

    Virginian Well-Known Member

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    Don't forget to calculate the effects of inter pellet turbulence.
     
  14. RaySendero

    RaySendero Well-Known Member

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    The G1 BC of a .33" round lead projectile is 0.039.
     
  15. RaySendero

    RaySendero Well-Known Member

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    I figure the drop will be closer to 15 feet at that distance.
    And not more that 30 ft-lbs of energy per pellet.
     
  16. sheriffjohn

    sheriffjohn Well-Known Member Supporter

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    When Hevi-Shot first came out I called the company to inquire if there was a buckshot load available for law enforcement use. Man I spoke to said not at that time but they'd done some study for the military using a test barrel and hanging meat. Penetration at over 100 yards was lethal. The test was to see if a cannister round would be useful. Faster than lead and super hard, I've used it ever since for waterfowl. Sometimes it goes through ducks and greatly increased killing range. Tighter groups, too.

    Shooting at a group of people isn't really a good idea for a legally defensible outcome.
     
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  17. RJF22553

    RJF22553 Well-Known Member

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    Ran through a ballistics calculator (http://gundata.org/ballistic-calculator/) a muzzle velocity of 1145, cal .33, 60gr, with a BC of .071 (will need to re-run with a BC of .039 and perhaps up the MV to 1325). Showed a 123.6" drop at 250 yards with 57 ft/lbs of energy per pellet.