PDA

View Full Version : savage



james
01-04-2008, 12:24 AM
Hi fellow shooters!
Just bought a .223 savage 200 cal, and would just like to know, at what distance does my bullets start dropping and what range should i set my scopes at? bullets are "american eagle .223 rem 55gr. fmj boat-tail", and scopes are atlas explorer "night predator 6-24x50 ffce", would appreciate your help.

regards james
eire

versifier
01-04-2008, 09:04 PM
Hi james,
Welcome to the forum.
The practical answer to your question depends upon what range your scope is zeroed for, and the actual (not Federal's listed) MV. Depending on your rifle and how it compares to their test rifle, the actual MV and the listed MV can vary by several hundred fps, so you have to actually measure it. The magnification of the scope doesn't matter, except to help you see the targets at longer ranges. It has no effect on the bullet's path (trajectory). The bullet path rises through the line of sight at close range and continues rising to the top of its arc, then begins to drop. The range at which it again passes through line of sight on its way down is the range for which the scope is zeroed. Knowing what the actual MV is (measured with a chronograph) you can figure rise and drop for any range using the ballistic table or a ballistic calculator.

For instance, with a Sierra 55grFMJBT at an MV of:

2800fps,
with a 100yd zero, bullet drop at various ranges is: 200yds -2.24", 300yds -5.71", 400yds 10.45"
200yd zero, rise at 100yds +4.48", BD at 300yds -6.93", 400yds -16.42"
300yd zero, rise at 100yds +17.12", 200yds +10.40", BD at 400yds -14.22"

3000fps,
with a 100yd zero, BD at: 200yds -1.72", 300yds -4.50", 400yds -8.17"
200yd zero, rise at 100yds +3.43", BD at 300yds -5.56", 400yds -12.92"
300yd zero, rise at 100yds +13.49", 200yds +8.34", BD at 400yds -11.04"

As you can see, even a mere 200fps makes for big differences at longer ranges.

Bill Church
01-11-2009, 11:16 PM
In reality your bullet statred dropping the second it left the barrel. Everything drops at 14 feet per second. The question is how fast is your bullet dropping and at what arc is required for the bullet to stay were you want it. The faster the bullet travels the less it drops per foot. The trick is the wieght and coefficiancy of the bullet so that it can retain its speed. The slicker the bullet the less speed it looses.