How accurate does a service rifle need to be?

Discussion in 'Shooting, Hunting and Fishing' started by stoatman, Jan 15, 2010.

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  1. An issue brought up on the LSW thread in the QM forum was just how inherently accurate does a service rifle have to be.

    My spur of the moment, back of the envelope opinion was that 3.5 MOA was probably adequate, since this would guarantee a 30 cm diameter circular group at 300 m for perfectly aimed shots, and thus guarantee torso hits if the soldier does his part.

    This, of course, would apply for professional army. For a massed conscript army, the 6-10 MOA of the AK-type rifles is probably adequate.

  2. There was a survey done last year on the killing ability of the average soldier,taken from various armies. The conclusion was that only one in ten soldiers actually properly aim to kill. In normal society these people would be classed as sociopaths (another thread there i think).

    My point is that we only need one in ten rifles to actually be accurate,and then issue those out to the correct men! :)

    Sorry have i missed the point again! ;)
  3. Agreed
  4. Glad you've started a thread on this.


    I think for the benefit of those not in the know, some definitions will be helpful at this stage.

    *Minute of Angle (MOA) A minute of angle is 1/60 of a degree of angle.

    This is almost exactly 1 inch at 100 yards or 29mm at 100m. We can round this to 30mm at 100m for ease of ready reckoning for any range we will be interested in.

    e.g. 1 MOA = 30mm group at 100m or a 60mm group at 200m, 120mm at 400m and so on.

    2 MOA = 60mm @ 100m, 120mm@ 200mm etc.

    4MOA = 120mm @ 100m, 480mm @400m

    Actual values are:
    MOA/ range M/ group MM
    1 100 29
    2 100 58
    3 100 87
    4 100 116
    5 100 145

    1 200 58
    2 200 116
    3 200 175
    4 200 233
    5 200 291

    1 300 87
    2 300 175
    3 300 262
    4 300 349
    5 300 436

    1 400 116
    2 400 233
    3 400 349
    4 400 465
    5 400 582

    1 500 145
    2 500 291
    3 500 436
    4 500 582
    5 500 727

    Theoretical accuracy

    The accuracy a rifle is capable of when errors associated with the shooter have been removed by mounting it on a stand or benchrest etc.

    Weapon System Error
    Weapon System Error is the acceptable Margin of Deviation from the intended point of impact for shots competently fired through a Zeroed Small Arm. The Deviation is caused by errors associated with the firer and the error budget associated with the SA and ammunition. (Ordnance Board Definition)

    This is a combination of the accuracy of the weapon/ammunition and the skill of the firer.

    It should be clear that if a SA is only capable of shooting to 3MOA then no matter how competent the marksman he cannot make it shoot better than that in the same way that Lewis Hamilton can't make a Ford Focus faster than it is designed and manufactured to be despite his skill.

    1MOA is typically what people expect a modern commercial sporting rifle to achieve.
    A modern Sniper rifle will shoot 1/2 or even 1/4 MOA
    A modern Benchrest rifle will shoot 1/4 MOA or better

    The acceptance standard for a WWII Lee Enfield Service rifle was about 2.5 MOA
    The original acceptance standard for SA80 as according to an ex SASC Captain I discussed this with. 36mm at 30m which is 4MOA

    For reference, a Figure 11 is 455mm wide. 4MOA at 400m is 465mm


    As I need to get doing other stuff right now I'll leave it at that for the moment but my first instinct on the topic is that 4MOA is required in Weapon System Error. To allow 2MOA of shooter error this would require a Theoretical Accuracy of 2MOA.

    (Edit for detail)
  5. Lee-Enfield acceptance was nearer to 4 MOA, 2.5 appears to be the "average" coming out of the good factories. It's in another thread somewhere, but I seem to remember it was a 1.5 inch square at 30 yards.

    If the one-in-10 rifleman theory is true, then give these 10% the shiny new sharpshooters Rifle and the other riflemen something capable of putting rounds down range and making noise, such as one of the 5.56 mm AK-rifles with an optic. Job done! Your one "proper" shooter is capable of nearer 1 MOA and the rest -- you don't care.
  6. 4(T) explained it in some detail and concluded:

    I'm happy to take 4(T)'s word on that as I know the bloke and he's as much of an authority on the topic as I think you could hope to meet.

    This seems to be what's happening.
  7. Interestingly, monsieur chauchat had the same idea 100 years ago -- the idea then was to give the one in 10 an automatic rifle and bucketloads of ammunition (hence his ultimate design, which is not actually intended to be a light machine gun), and let the others carry normal rifles with bayonets and more ammunition for the automatic rifleman.

    Now that everybody has an automatic rifle, we have similar thinking but along the lines of accuracy.
  8. Do you have any sources for this?

    I have previously seen 'statistics' quoted saying that the proportion of soldiers who actually aimed to kill during WWII was one in a couple of thousand, (though this was again an unattributed source) but that selection and training meant that the majority of infantry soldiers could now be expected to kill an enemy where required.
  9. There was a documentary on this a while back, I believe that by the end having worked though the ages and phycology ,that the figure is about 1in 3 now.
  10. Accurate enough to encourage the enemy to keep his head down. As long as the enemy believe you have an accurate weapon, which is operated by a competent user, the maths is actually irrelevent IMHO.
  11. mmmm what a silly question you silly person.
    Obviously we don't need accurate rifles, because we don't want to hurt anybody do we???
    So to follow your thread, lets have really wobbly bullets, bent barrels and no sights.
  12. ex-Stab is confusing the issue with facts, accurate facts but never the less a little wide of the point. I would tend to agree with TT.

    A determined soldier with a weapon of moderate accuracy will beat a moderate soldier with an accurate weapon. Apart from sniping, most small arms (not including MGs) see use at short ranges, eg FIBUA. Therefore talk about MOA is academic. The real killer on the battle field since WWI has been artillery. Afghanistan is something of an exception.

    Last thought, the question reminds me of the one about "how long is a piece of string?
  13. So, referring to the title of the thread, how accurate does it need to be then? At what range does a soldier of average skill need to be able to hit a human? That's the criteria I have applied.

    For example. I've fired slug in a shotgun at 110 m and failed to hit a fig 11. Consistently. Is that "academic"?
  14. Interesting point. The Jerries did a survey in 1944 before they built the first assault rifle, and found 80% of small arms engagements took place within 200 meters. I guess the French looked at that before designing FAMAS. The Russians certainly did before they designed the AK-47. I wasn't infantry, but I find it hard to understand why we ended up with something a hell of a lot less reliable than an AK-47 but far more accurate. I'd say, leave everything over 300m to the SF machine gun people and snipers, put reliability first. Actually, you don't even need to do that! There's plenty of reliable rifles that can hit a man out to much longer ranges.....just ask H&K for one, instead of re-inventing the wheel next time.