Ballistics trajectory and other geometry

[Ode1891]

I just got some bullets and sabots to sight in a brand new Accura MRX. I rarely get shots beyond 80 yards, so I’d prefer to sight in at 50. Actually, if the range allowed it, I’d set a target up at 75 yards. The ballistic charts on the Barnes 250s show sighting in at 150. If I sight in at 50 yards, is there a table showing me poi at 100? I will lob a couple at 100 yards, but I was wondering if any charts show ballistics if zeroed at 50. I know it all depends on the charge, barrel length etc…. Just looking for a chart with 50 yard zero

Shooting Barnes TEZ 250 s. Will start with 90 GR by volume but will measure weight to be consistent.

Thanks

 

[txhunter58]

I would sight in 1-1.5” high at 50 yards. You will be almost dead on at 100. Never have to think about it again. Just aim and shoot out to 100.

Ballistics charts and math gets you on the ballpark. But you have to do the work to see what your gun does.

 

[txhunter58]

Standard is 100 gr powder. Magnum is 150

Keep in mind that triple seven powder is hotter than 100 grains on these charts. 90 grains of triple seven would be about the same as 100 grains on these charts.

 

[edmehlig]

I can set up a portable target at 75yds at my club's range. Once it's sighted in at that range I shoot at 50 and 100 yds. I find I'm about 1.5 " high at 50 and about the same at 100 yds.

 

[txhunter58]

I am not quite sure I understand what you are saying; but if you are dead on at 75, don’t see how you would be high at both 50 and 100

 

[Ode1891]

View attachment 43021
Standard is 100 gr powder. Magnum is 150

Keep in mind that triple seven powder is hotter than 100 grains on these charts. 90 grains of triple seven would be about the same as 100 grains on these charts.

My eyes don’t do so good at 100 yards with 7 power, so in the past I’d lob a couple at 100 to get a general idea and they were . At 50 yards I ended up settling around 1”-2” high usually. Looking forward to shooting the new rifle. Need to measure out and weigh some powder loads. Never thought about bothering to weigh before reading posts on here. Edited.

 

[Ode1891]

I can set up a portable target at 75yds at my club's range. Once it's sighted in at that range I shoot at 50 and 100 yds. I find I'm about 1.5 " high at 50 and about the same at 100 yds.

You must use a light powder load and heavy bullets ? Thanks

 

[DJ_Brutus]

Numbers used:

250 gr Barnes TEZ
.194 BC
1800 fps (assuming BH209?)
1.5” sight above bore

 

[ENCORE50A]

I am not quite sure I understand what you are saying; but if you are dead on at 75, don’t see how you would be high at both 50 and 100

Because the bullet is still rising.

 

[DJ_Brutus]

I am not quite sure I understand what you are saying; but if you are dead on at 75, don’t see how you would be high at both 50 and 100

I’m guessing he means high at 50 and about the same (as 75 yards) at 100.

Otherwise doesn’t seem logical.



Don’t see how it could be higher at 50 & 100 than at 75.

 

[ElDiablo]

Need to measure out and weigh some powder loads. Never thought about bothering to weigh before reading posts on here.

Unless you are terribly inconsistent with your volume measuring technique (maybe weigh a few of your volume charges to check that) - weighing isn’t likely to make any difference in your shooting at 50-100 yards.

 

[txhunter58]

I have yet to weigh a powder charge and shoot 2-3” groups out at 100 with open sights.

I would def not weigh to work up a load. Try several dif amounts of powder and when you find the amount of powder that does the best, then you can weigh if you want to

But remember to measure it out in volume, then dump it on the scale to see how much it weighs, then use that weight from then on.

 

[anonymouscowherd]

If you have a chrono and know the BC of the bullet you can use one of the many online trajectory calculators

But even then I would only use it as a guide. You need to zero where you want it zeroed and then shoot groups and build a dope sheet for shorter and longer distances

 

[ENCORE50A]

https://www.rifleshootermag.com/editorial/ballistics-for-dummies/83897

 

[DJ_Brutus]

https://www.rifleshootermag.com/editorial/ballistics-for-dummies/83897

George, we need some context as to whom this is for, but I’m guessing this was directed to @txhunter58 and myself?

Could you show us a ballistics path where POI is higher at 50 yards and 100 yards than it is at 75 yards. With your experience and long range skills, I defer to your judgment, but I’m just not following. Maybe I’m too dumb to be a dummy.

 

[txhunter58]

There is no need to involve any kind of sophisticated ballistics charts for what he wants. If he sights in at 1” high at 50 yards, then tests it at 50 and 100, he will be in the ballpark. He might then have to tweek it up or down slightly.

 

[txhunter58]

I suspect what edmehlig meant to say is that he sights in at 25 yards. Then his statement makes sense. Even for a dummy like me

 

[ENCORE50A]

290gr Barnes T-EZ @ 1,900fps ZEROED at 75yds.

 

[DJ_Brutus]

290gr Barnes T-EZ @ 1,900fps ZEROED at 75yds.


View attachment 43037

Lower at 100 than 75. Your original statement makes ZERO sense

 

[ENCORE50A]

https://www.rifleshootermag.com/editorial/ballistics-for-dummies/83897