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rab 01-02-2010 10:34 AM

Trajectory Tables
Any of you technically savy types can chime in....

I changed my ammo from PMC Bronze 55gr for something better. I now shoot mil surplus FMJSCBT 62gr LC "Grn Tip". They seem to fly tighter. I zeroed for 100. Good tight groups. However, my 50yd impact is 6-8" low? Is there that much difference or is it me? Does any one have or know of the trajectory table for CAR/M15 using 62gr? I heard that the FMJSCBT stuff will fly very different but that much?

Stag Arms Mdl 1
16" Chrome lined
EoTech 516 w/5XMako

I shoot bench, standing, kneeling and prone with pretty much the same results. I didn't notice with my old ammo. I may have improved some since last year....

thank you ahead of time......

inmate of Md 02-27-2010 08:00 PM

Go to this link and plot the bullet and load. It should answer your question.

One thing to share, People question the point of impact.

You load a bullet and shoot, Change to a hotter load, bullet is traveling faster. And the point of impact actually changes to a lower place on the target?
One of this reasons for this is barrel flex or vibrations. When you fire the rifle, the barrel whips in a circular motion. The thinner and longer the barrel the more whip. high or low shots on the target may be result of the barrel arc position when the bullet leave the bore.
When you load develop the practice is finding the best node tune point. Loads at the highest and or lowest point of the arc is the hardest to keep accurate. Just before or after the top of the arc is best.
I hope this helps,
Link is to the JBM ballistic site, is free to use.

JBM - Calculations - Trajectory

Catfish 03-02-2010 12:41 AM

Easily can be. You are now shooting at a lower velocity and my have less muzzle jump or some other things comming into play. No matter what the book says where the bullet is hitting is the final answer. You will ALMOST never find 2 different weight bullets shoot to the same point of impact. It does happen rearly, but evedently not this time.

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