Newbie ballistic table question

[Shrinkmd]

I was looking at the 7.62x54r.net ballistic tables, since I want to try out my Mojo sighted 91/30 at the 200 or 300 yd range. Due to the target frame setup, I really need to be "on paper" with the correct drop at 100 yds before messing up the expensive target frames on the high power.

It looks like the Hungarian light ball drops 7 inches in actual path from 100 to 200 yds



Am I reading this correctly? I looks like I need to be 7 inches high at 100 to be on target at 200?

Thanks for the help.

 

[Don't Tread On Me]

It is 7.5" lower at 200 than it was at 100. That's the generic drop of the bullet.


However, the other line shows the path based on a particular zero. If you are zeroed at 200, it is 2.5" high at 100. If you are zeroed at 100, you cannot say that you will be 7.5" low at 200.

Am I reading this correctly? I looks like I need to be 7 inches high at 100 to be on target at 200?

No. That line is already a 200 yard zero. That means 100 yards is 2.5" high, not 7" ...a 7" high at 100 will put you zero way further than 200 ...

 

[Shrinkmd]

Uh, ok. So if I am zeroed nicely at 100 yds, how do I figure out using a table how high I need to be at 100 to be on paper at 200?

I've been doing some web searches but haven't been too successful yet.

 

[rangerruck]

so , the blue line just shows you , the drop of the bullet, if your rifle started off
exactly prllel to the ground, the other line shows you the actual trajectory of a 200 yd zero. So then, if you are sighting in at 100 yds only, you should be approx 2.5 inches high at 100 yd, and this will put you very close to zero at 200, theorhetically. And approx. 10.3 inches high at 100 , to be on at 300.
However, this is for a very particular type of ammo, this lot of Hungarian.
This may not , proly will not, hold true for any other ammo you try, especialy newer loaded factory stuff.

 

[DMK]

how do I figure out using a table how high I need to be at 100 to be on paper at 200?

Ignore the blue line. The red line is telling you what you want to know. Notice it crosses 0" at 200 yards? Notice it's about halfway between 0" and 5" at 100 yards?

The rule of thumb is a 200 yard zero will be about 3" high at 100 yards for most .30 cal ammo in this power range (30-06, 308, 7.62x54R, 7.5 Swiss, 303 Brit, etc).

Keep in mind, this is a rough estimate. The only way to know for sure is zero at 200 yards.