trigger happy tikka 0 Posted January 2, 2011 Report Share Posted January 2, 2011 hi just taking an interest in to how people like to zero their rifles as most of my shots are long range and was interested to see their is a better way than i am using which is zero at hundred meters and would also like to know how far a 22.250 will shoot flat before drop off cheers Quote Link to post
matt_hooks 188 Posted January 2, 2011 Report Share Posted January 2, 2011 What ammunition are you using? The box often has information about the trajectory, and best zero range. What do you consider a "long range" shot? Quote Link to post
trigger happy tikka 0 Posted January 2, 2011 Author Report Share Posted January 2, 2011 i am using home loads sierra 55 grain heads h414 powder and winchester primers long range was bad words to use i usually get foxes in at about 250 300 yards when lamping they never want to come any closer dont blame them lol Quote Link to post
masmiffy 82 Posted January 2, 2011 Report Share Posted January 2, 2011 I am no expert but as far as I am aware no rifle shoots truly 'flat' Trajectory has to occur! There are online ballistic calculator charts where you can programme in sight height bullet weight/type velocity wind speed etc They are an interesting insight to trajectory etc thats for sure!! Quote Link to post
matt_hooks 188 Posted January 2, 2011 Report Share Posted January 2, 2011 I am no expert but as far as I am aware no rifle shoots truly 'flat' Correct, gravity's not optional, it's the law! Trajectory has to occur! There are online ballistic calculator charts where you can programme in sight height bullet weight/type velocity wind speed etc They are an interesting insight to trajectory etc thats for sure!! Get your mitts on a chronograph and measure your MV, then google "ballistics calculator" or similar. ArmChair pro I've heard is good. Put the details in, so MV, bullet details (ballistic coeffisient, mass, twist rate etc.) and it should tell you where to zero for maximum point blank range (not, as the press seem to think, with the muzzle touching the target, but actually the range of distances where a bullet will fall within the radius of a circle of the required size if the aim point is kept the same, for deer a 4" circle for example) For my .243 I zero 1" high at 100 yards, which with the 105 grain GECO's gives me a point blank range of about 25 yards to 235 yards on deer. So between 25 yards and 235 yards, if I point the rifle at the middle of the chest, the bullet will not strike more than 2" high or low. The 22-250, from what I understand, is fairly similar to the .243 in trajectory, but let the ballistics calculator work it out for you! Quote Link to post
Finkley 1 Posted January 3, 2011 Report Share Posted January 3, 2011 According to Dr. Cox and presumably others, gravity isn't even constant, there are hot spots and they continually shift, almost like the flow of water. It's a miracle we hit anything except the floor considering the variables. Quote Link to post
RicW 67 Posted January 3, 2011 Report Share Posted January 3, 2011 I just now googled MPBR and had a look at a chart for a 22-250 firing a 50gr V-Max @3700fps. Rounding off the figures, zeroing at 250 yds will give POI no more than 2" high or low from under tha muzzle to 300yd. It is 1.6" high at 100yds. Remember that a heavier bullet does NOT fall faster than a light one. The important figure is the MV Ric Quote Link to post
trigger happy tikka 0 Posted January 3, 2011 Author Report Share Posted January 3, 2011 cheers for all the info i will take all this in to concideration when going to zero my rifle Quote Link to post
matt_hooks 188 Posted January 3, 2011 Report Share Posted January 3, 2011 I just now googled MPBR and had a look at a chart for a 22-250 firing a 50gr V-Max @3700fps. Rounding off the figures, zeroing at 250 yds will give POI no more than 2" high or low from under tha muzzle to 300yd. It is 1.6" high at 100yds. Remember that a heavier bullet does NOT fall faster than a light one. The important figure is the MV Ric Ric, indeed, in terms of time a heavier bullet does not fall faster than a light one, gravity is (relatively) constant. HOWEVER... The trajectory of a heavier bullet will appear more curved (for a given ME) because the heavier bullet will travel less horizontal distance for the same vertical displacement. So timewise, it will be at the same point vertically, but distance from muzzle wise it will drop more quickly. As you say, if the muzzle velocity is the same then the trajectory should be the same (BC and so on taken into account) but heavier bullets tend to move less quickly! Quote Link to post
RicW 67 Posted January 3, 2011 Report Share Posted January 3, 2011 I just now googled MPBR and had a look at a chart for a 22-250 firing a 50gr V-Max @3700fps. Rounding off the figures, zeroing at 250 yds will give POI no more than 2" high or low from under tha muzzle to 300yd. It is 1.6" high at 100yds. Remember that a heavier bullet does NOT fall faster than a light one. The important figure is the MV Ric Ric, indeed, in terms of time a heavier bullet does not fall faster than a light one, gravity is (relatively) constant. HOWEVER... The trajectory of a heavier bullet will appear more curved (for a given ME) because the heavier bullet will travel less horizontal distance for the same vertical displacement. So timewise, it will be at the same point vertically, but distance from muzzle wise it will drop more quickly. As you say, if the muzzle velocity is the same then the trajectory should be the same (BC and so on taken into account) but heavier bullets tend to move less quickly! Zackly my point! For the OP tho, the point I would make is that if he zeroes at j-j-j-u-st over 1.5" high at 100yds he will be no more than 2" high or low out to 300yds if he just puts the cross hairs dead on. I don't think Charlie will care! Quote Link to post
SNAP SHOT 194 Posted January 3, 2011 Report Share Posted January 3, 2011 If you get the lend of a chronograph zero at 100 yards and dial in drop thereafter if your scope suits, takes the guesswork outta it, and the only thing then is shooter error, Less guess work equals more sucess... if just point and shoot and your not passing 300 yards then zero at 200, Its your decision. ATB Snap. Quote Link to post
Colster 1 Posted January 4, 2011 Report Share Posted January 4, 2011 Bear in mind though, that zeroing at 250yards involves either really big binos, a scope with lots of mag, a lot of walking to and from the target or a brave mate with a walkie talkie. Once you've worked out your trajectory you should know your primary zero, for example I zero my HMR at 50yards (this gives me a MPBR of 30 to 140yards (based on a 1" killzone)), this way I can do most adjustments from the gun without having to walk to the target after every group. Every now and then when time and space allow I'll do a longer range test at around 120yards for a bit of fine tuning but generally the 50yard one works fine. Quote Link to post
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