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BUCK CONNER
Editor - Staff Writer

   Smoke Signals

                   Sep./Oct. '10

 

Sighting at 50 Yards to be on at 150 to 200 yards?

   New muzzle loading customers, quite understandably, ask this question again and again. We wish that we could give an accurate answer, but the fact of the matter is that there is just no shortcut to learning the trajectory of your muzzle loading rifle with the projectile you have chosen, your powder charge, and ambient conditions you hunt in.

   Trajectory is figured on two basic factors: muzzle velocity and the ballistic coefficient (BC) of your bullet. Guns vary quite a bit, and just because one shooter records a number on a chronograph with his identical model rifle in no way does it mean that your gun will shoot at the same velocity. You really need to do your own chronograph work. A rumored velocity may be off by 200 fps in your gun or even more.

   Most muzzle loading bullet manufacturers use static ballistic coefficients. No mention is made of how these numbers are derived, at what range, velocity, ambient conditions, and so forth.

   Most of today's hunters use the popular saboted projectiles in .45/.50 caliber with weighs 250 to 350 grains. Only so much can be done to such a projectile to make it fly better. A few hundredths of a ballistic coefficient point can be gained by changing the nose profile, and adding a boat tail can make small gains, but there are practical limits in this caliber and weight range. Anything over a .210 BC should be considered good.

   For our purpose of round balls, a personal chronograph is needed, there are  economical units available and widely distributed. The budget minded shooter can usually go in with his shooting buddies to off set costs. At least it gives you a good starting point.

   Once a suitably accurate load is found with a small velocity deviation, you can fly your bullet over that chronograph at 100 yards. Those readings leave no doubt as to the velocity (and energy) of your bullet at 100 yards. With that knowledge on your personal load you have more information than any powder manufacturer, gun maker, or bullet maker could provide to you. Using muzzle velocity and 100 yard velocity, you can use free software, such as the "Point Blank" program from HuntingNut.com, to give you a 150/200 yard numbers that has some basis in reality, and some relation to actual field results.

   There is no real substitute for doing your own shooting, if you can't hit what you are shooting at under range conditions, what hope do you really have for successful shot placement in the field? The debates about bullets come and go, but nothing can possibly compensate for poor shot placement. A load that groups at 100 yards may not be acceptable at 150/200 yards but an accurate load at 150/200 yards seldom has any trouble at 100 yards!

   Hope this helps some of you that have asked us this question.

                                                                       Later

Buck Conner

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updated  09/10/2010   

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