40 carbine accuracy?

Discussion in 'Vintage Topic Archive (Sept - 2009)' started by Jackpine Savage, Dec 23, 2007.

  1. Jackpine Savage

    Jackpine Savage Member

    I'm just wondering what kind of accuracy to expect out of a 40 S&W carbine? I can get goo groups at 25, 50 and 75 yards but at 100 they open up to patterns not groups. I took the rear sight off and locktited it down and thaty helped as did putting a shim so that the rear sight couldn't move side to side in the bracket, but I still get 6" or larger groups at 100 yards. Is this normal?

    Take Care and Stay Safe
  2. GlockMan

    GlockMan Member

    Depends on the ammo and your shooting ability, if you have a 12X or 16x scope bolt it on and shoot for accuracy. My 4095 loves Speer Gold Dots and will shoot them in a 2.5 to 3.0 inch 100yd groups all day long. Thats more then enough accuracy for most situations.

  3. inherent accuracy of the carbine .. long post

    The accuracy of the carbine depends on several factors:

    a. The rate of twist of the rifling
    b. The ballistic coeficient of the bullet being fired
    c. The shape of the bullet
    d. The caliber of the bullet
    e. The stability of the barrel
    f. The velocity of the bullet

    A consideration is that the carbine that you are shooting is firing a "pistol" based cartridge. The ballistic coeficient of that bullet, whether FMJ or hollow point is not condusive to long range shooting. Remember it was designed for "pistol" range performance. By shooting it in a carbine does not turn it into "rifle" cartridge performance. Look at a bullistics table for that particular round and look at the bullet drop and velocity at each range point. For the carbine you can extrapolate by adding a bit to the velocity or if you have a ballistics software program, you can plug in the data and see the results.

    Most weapons are far more "accurate" than what the average shooter is capable of performing. There are those who have the ability to consistantly perform the aiming, stabilizing, and actuating the trigger in the very same manner time after time. Those individuals are few. Most times it takes months and even years of training and practice, practice, practice.

    Now with that all being said. You state that your groupings at 25, 50, and 75 are good (what do you mean as good?.. what are your grouping sizes) and that at 100 yards, they are more like patterns at over six inches. Look at your targets at each range and look at the shape of the hole. Are thy all evenly round or do you see some tearing as in tumbling of the bullet?

    If you want to see what the inherent accuracy of you particular carbine is, then you need to use a rifle rest that you can consistantly place in the same position from shot to shot. From that data you can tell what that particular carbine is doing at each range point. And remember, that the further you go out, the larger your grouping will be. A MOA (Minute of Angle) difference at 25 yards is not the same as at 100 yards. Just as an example a little over one inch separation of two bullet strikes at 25 yards can translate to nearly 6 inches at 100 yards. To me, one inch groupings at 25 yards are not to be sneezed at.

    So to go back to your original question, my performance with my .40 S&W carbine is about 2 inches with my elbows on the bench but not otherwise supported. I have my scope dialed in at 25 yards.

    Hope this has answered some of your questions. Please ask if you have more to discuss... GRIN

    Take care,

  4. Jackpine Savage

    Jackpine Savage Member

    Not counting the odd flier, one ragged hole or rather 2" groups at 75 yards using the factory sights. I did get better results using factory ammo. So far I've only used 155 and 165 grain ammo, does yours like the 180's better?

    Thanks for the info.

    SHOOTER Z Well-Known Member

    My 4095 with a red dot can hit COM at 100 yrds.