Pirate 4x4 banner

1 - 9 of 9 Posts

·
Registered
Joined
·
854 Posts
Discussion Starter #1
I have looked at ballistics charts but am getting stump since I hate math...
I want to ZERO my 7mm mag at 200yds but can only get to a 100yd and 50 yd range

Can someone tell me at a zero of 200 yds how many inches above the point of aim should the bullet be hitting at 50 yds
This is what I have so far at 100 yd ZERO not the 200 yds I need

Bullets in question would be
WINCHESTER SUPREME 7MM REM MAG 140GR BALLISTIC SILVERTIP

WEIGHT/STYLE/BRAND/VELOCITY/ENERGY/200/300/400/500/Sleeve
7mm Mag 140 BTsb Nos 3160 3104 /-2.5/-9.5/-21.8/-40.2 5002
Thanks
 

·
Registered
'73 Scout
Joined
·
10,459 Posts
I have looked at ballistics charts but am getting stump since I hate math...
I want to ZERO my 7mm mag at 200yds but can only get to a 100yd and 50 yd range

Can someone tell me at a zero of 200 yds how many inches above the point of aim should the bullet be hitting at 50 yds
This is what I have so far at 100 yd ZERO not the 200 yds I need

Bullets in question would be
WINCHESTER SUPREME 7MM REM MAG 140GR BALLISTIC SILVERTIP

WEIGHT/STYLE/BRAND/VELOCITY/ENERGY/200/300/400/500/Sleeve
7mm Mag 140 BTsb Nos 3160 3104 /-2.5/-9.5/-21.8/-40.2 5002
Thanks

Assuming Im reading what you typed right, you have a 2.5" *chart-book value* drop at 200 yds in comparison to 100 (zero), now all ye need to do is convert 2.5" into MOA or scope "clicks", that help? :D

D.
 

·
Registered
Joined
·
854 Posts
Discussion Starter #4 (Edited)
Stats on cartridge/bullet from winchester

VELOCITY=3160 at muzzle
ENERGY=3104 at muzzle
I dont have access to a chrono :confused: still can't help me?

There is no way to "measure" if it zero's at 200 and it's 1.3" above point of aim at 100 yds where it hits at 50 yds?

Thanks

ps I'm not looking for scope clicks and MOA I know that, I'm needing to know where it hits at 50 yds to sight it in at 200 ...ie if I can only go to a 50 yd range I could sight it in for 200 yds at the 50 yard range (it's suppose to hit 2 inches above point of aim at 50 yards etc etc)
 

·
Registered
Joined
·
771 Posts
Stats on cartridge/bullet from winchester



I dont have access to a chrono :confused: still can't help me?

There is no way to "measure" if it zero's at 200 and it's 1.3" above point of aim at 100 yds where it hits at 50 yds?

Thanks

ps I'm not looking for scope clicks and MOA I know that, I'm needing to know where it hits at 50 yds to sight it in at 200 ...ie if I can only go to a 50 yd range I could sight it in for 200 yds at the 50 yard range (it's suppose to hit 2 inches above point of aim at 50 yards etc etc)
How far are you planning on shooting?

The reason I ask is because if you are looking for a 200yd zero and plan on using that as a reference for point blank range, the values will be off at longer distances depending on a number of factors.

Barometric pressure, humidity, B.C. of projectile, and most importantly actual velocity from your rifle are all factors that need to be established if you plan on using this data for extrapolating past 200.

I can run rough numbers for you based on what the box says, but I've never known advertised velocity to be close to actual. Give me a minute to pull up the B.C. of that bullet. You wouldn't happen to know the altitude where you're shooting would you?
 

·
Registered
Joined
·
771 Posts
Given a sight height above centerline of the bore of 1.5" (if this doesn't match what you have let me know and I can run it again), and "average" environmental factors, here's what I come up with ROUGHLY... Do not use this as absolute.

Distance Path Velocity
25yd -0.5 3108.2
50yd +0.3 3057.3
75yd +0.9 3006.7
100yd +1.3 2956.6
125yd +1.3 2907.5
150yd +1.2 2858.6
175yd +0.7 2810.5
200yd 0.0 2762.7
 

·
Registered
Joined
·
1,967 Posts
Bob Forker's book, "Ammo & Ballistics" lists the data for the majority of commonly available factory loads. They list the data for that specific round. They show it out of a 24" barrel with a 1 in 9.5 twist, which is pretty standard for an off the shelf 7mm mag. As other's have mentioned, this is a calculation and a baseline, but it would likely be close enough for deer hunting at 200 yds or so. They show -.1 at 50 yds and +1.3 at 100 yds to be on zero at 200 yds.
 

·
Registered
Joined
·
854 Posts
Discussion Starter #8
Thank you fisheadgib and brian. I see now that Iwill have to use at least the 100 yd range to get my "accurate" zero at 200... I shoot in Az and 200 yd zero especially for this caliber seems spot on. I don't plan on shooting anything past 400 yds but like it was suggested at some other time, zero to hit a dinner plate no matter what distance to always hit vitals

Thanks again
 

·
Registered
Joined
·
12,996 Posts
The nice thing is that, out to probaby 300-400 yards, the 7mm is so flat-shooting that a decently zeroed rifle at 50 yards is going to be plenty close enough. YOUR ability to hit the target at that distance is a much bigger factor than the bullet's trajectory.

What I'm trying to say is that if you're good enough to group decently at 300 yards, the bullet will 'miss small' enough that you'll still be guaranteed to hit vitals. For most people, the fact that they can't shoot worth a damn at long distances is a much bigger problem than the bullet landing a couple of inches low. Somehow, though, the rifle's zero usually gets the blame for this.:D
 
1 - 9 of 9 Posts
Top