100 yd elevation for 500 yard zero??

R

relodr36

Guest
The old geezers at our club have a 500 yard shoot this week.
Does anybody have a feel for what 100 yard elevation I need for this caliber/load?

Caliber -.220 swift.52 gr Speer HP at measured 3830 fps MV.
Bullet Coefficient = .225 Sectional density = 0.148

This is a cash shoot(we're big spenders - $5 entry) and is for smallest group size.This load will regularly shoot 5 shots the threes or fours at 100 yards,even if it isn't the best ballistically.
Thanks!
 
I ran your data through my Exbal. I don't understand what your asking for. If you have a 500 yard zero with that bullet you need -7.25 moa for 100 yards. The opposite holds true for a 100 yard zero, you would need +7.25 moa for 500 yards.
Hope it helps
vinny
 
Thanks!

Thanks,Vinny!
I wanted an idea of how high above the line of sight at 100 yards,I should be in order to be zeroed at 500 yards.
This will save ammo and/or going back and forth.I cant see .224 bullet holes with my 45X Leupold spotting scope,much beyond 200 yards.
It's pathetic how parts start to degrade when you get into your 70's.
 
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Relodr36:

Sierra Infinity balistics program readout sais sight in 10.21 inches high at 100 yards and you should be dead on at 500 yards.

Good luck:D
 
Thanks,men!

Thanks to all you guys for your help and your time!
I had it set at 6.0 inches high at 100,yesterday. So I'll come up 6 more clicks.
We use the regular high power league targets,so there is ample room.
 
Just a thought... you might want to play around with and learn to use JBM - its a free online ballistics calculator. Then you can answer these questions any time, and start playing 'what if' ;)
 
results

Our old,retired geezers group at the club had our 500 shoot Wed.
With a +7.5" zero at 100 yards,i was about 24" low at 500.I had to come up 20 clicks,which should be about +12.0" at 100 yards.
I suspect the difference between this and you fellow's calculations may be due to:
1. Speer has an optimistic BC for this bullet.It has a pretty wide cavity hollow point and is designed as a varmint bullet.
and/or
2. The chrono (Chony) results for this load are too high.(39.5 gr Win760).Most handbooks indicate it ought to be about 3650.

The only thing I won was the notoriety of being the oldest shooter entered(73).I guess the alternative is worse,but I sure can't see and shoot like I could 10 years ago.
Thanks,Guys
 
73 aint soooo old! I'm 49 and I can't see like I did 10 years ago so you're not alone. As far as the scope adjustments go, my Exbal has never been off by more then a couple of clicks from 300 to 1k on any on my rifles and or loads. Chronys have been known to be wrong.
Good Luck
vinny
 
I ran the calcs. and came up with a -7.8 MOA for your 100 yard setting. But looks to me like we're all pretty close so I wouldn't worry too much.
 
Well, it sounds like you had a good time anyways (always a plus). Even so, something doesn't quite add up...

Even assuming the Chrony was a couple hundred (200) fps off, which is not unheard of, but still its a fair bit off even for a Chrony, and the BC is maybe a bit optimistic (was it the 52gr TNT, the one with a huge hollow point - almost like a .224 cal wad-cutter?), and putting you at standard atmo conditions - 59°F, 29.92" Hg, 0% RH, 0' above sea level... if you were 24" low, thats about 4-3/4 to 5 moa off... which at 500yds is pretty tough to be that far off. If you came up 20 clicks to be on call, then that works out about right (rougly 5 moa at that distance). The question is how the heck is a .220 Swift dropping that much; 7.25 moa + another 5 moa, or 12+ moa total drop from 100 to 500yds? That seems like an awful lot to me.

Thats the sort of thing that drives me batty until I get it figgered out - usually either I made a mistake zeroing some where along the line or entered the wrong numbers in the ballistic program, etc. but I don't think I've ever been 5 moa off @ 1000yds with a .308 Winchester, much less that far at half that distance with a flat-shooter like a Swift...

Well, if you get bored, check out that link I gave ya earlier to JBM and play around with the values (the 'Trajectory (Simplified)' option will probably be the easiest to begin tinkering with) and see what happened. At any rate, congrats on getting out and keeping them young-uns on their toes ;)

Take care,

Monte
 
Trajectory for Speer .224 dia. 52 gr. Match BTHP at 3830 Feet per Second
At an Elevation Angle of: 0 degrees
Ballistic Coefficients of: 0.23 0.23 0.23 0.23 0.23
Velocity Boundaries (Feet per Second) of: 1800 1800 1800 1800
Wind Direction is: 3.0 o'clock and a Wind Velocity of: 10.0 Miles per hour
Wind Components are (Miles per Hour): DownRange: 0.0 Cross Range: 10.0 Vertical: 0.0
The Firing Point speed of sound is: 1134.22 fps
The bullet does not drop below the speed within the max range specified.
Altitude: 213 Feet Humidity: 75 Percent Pressure: 29.53 in/Hg
Temperature: 72 F
Data Printed in English Units

500Yd Zero
Range/fps/Nrg/path in inch/path in moa/Wind inch/Wind Moa/FlightTime
0 3830.0 1693.4 -1.6 0.0 0.0 0.0 0.0000
100 3354.7 1299.2 7.31 7.0 0.95 0.9 0.0837
200 2927.8 989.6 13.11 6.3 4.02 1.9 0.1795
300 2539.0 744.2 14.82 4.7 9.6 3.1 0.2896
400 2181.4 549.3 11.1 2.6 18.26 4.4 0.4170
500 1854.5 397.0 0.0 0.0 30.73 5.9 0.5662

100Yd Zero
Range/fps/Nrg/path in inch/path in moa/Wind inch/Wind Moa/FlightTime
0 3830.0 1693.4 -1.6 0.0 0.0 0.0 0.0000
100 3354.7 1299.2 0.0 0.0 0.95 0.9 0.0837
200 2927.8 989.6 -1.51 -0.7 4.02 1.9 0.1795
300 2539.0 744.2 -7.1 -2.3 9.6 3.1 0.2896
400 2181.4 549.3 -18.13 -4.3 18.26 4.4 0.4170
500 1854.5 397.0 -36.54 -7.0 30.73 5.9 0.5662

7 moa to get from 100 to 500 with the 52g at this Vel
 
Just a thought

The adjustments to the scope could have been the wrong way?? Been known to have happened.
 
oneflyer said:
The adjustments to the scope could have been the wrong way?? Been known to have happened.
Click to expand...
Possibly,but I keep a record of my scope settings in my shooting log and it checks out.


The day was cold(35F) and damp.There was about a 5 MPH headwind and this bullet has a big hollowpoint,as it's designed for varmints.
I had a good time and now I've got another project to play with.The 14" twist on this Ruger supposedly limits the bullet weight,but I'm going to get some heavier bullets to try.
When the weather gets back to normal(?) next week,I'll try it at 100 yards with this setting to see if it is about 12" high.
Thanks,guys,for your time and input!
 
Part of this could be that the bullet is really the 52g HP with it's big opening and .168 BC, but you would have to slow it down to 2935 or so and be at sea level to have these comeups :)

Trajectory for Speer .224 dia. 52 gr. HP at 2935 Feet per Second
At an Elevation Angle of: 0 degrees
Ballistic Coefficients of: 0.168 0.168 0.168 0.168 0.168
Velocity Boundaries (Feet per Second) of: 1800 1800 1800 1800
Wind Direction is: 3.0 o'clock and a Wind Velocity of: 10.0 Miles per hour
Wind Components are (Miles per Hour): DownRange: 0.0 Cross Range: 10.0 Vertical: 0.0
The Firing Point speed of sound is: 1134.22 fps
The bullet drops below the speed of sound on the trajectory (1134.25 fps) at: 440 yards
Altitude: 0 Feet Humidity: 75 Percent Pressure: 29.53 in/Hg
Temperature: 72 F
Data Printed in English Units

Range/fps/Nrg/path in inch/path in moa/Wind inch/Wind Moa/FlightTime
0 2935.0 994.5 -1.6 0.0 0.0 0.0 0.0000
100 2406.1 668.4 0.0 0.0 1.88 1.8 0.1129
200 1936.1 432.7 -4.51 -2.2 8.37 4.0 0.2520
300 1531.7 270.8 -18.48 -5.9 21.08 6.7 0.4264
400 1221.3 172.2 -47.52 -11.3 41.89 10.0 0.6468
500 1036.5 124.0 -99.9 -19.1 71.2 13.6 0.9156
 
That's it! #1035

Yes,it's their 1035 bullet,that's designed for varmints.
Bob Hagel turned me onto them,so I bought 2000 about 15 years ago.I've had many 5 shot groups under 1/2" in both of my .220's.
They also group well in my AR,usually around 1"-1.250".
Thanks for the ballistic data.
 
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