HuntingNet.com Forums

HuntingNet.com Forums (https://www.huntingnet.com/forum/)
-   Black Powder (https://www.huntingnet.com/forum/black-powder-23/)
-   -   Climbing trajectory (https://www.huntingnet.com/forum/black-powder/176355-climbing-trajectory.html)

TXFRNTLDER 01-20-2007 06:09 PM

Climbing trajectory
 
So I have a load of 95 grns. and the 240 grn XTP seems to be working pretty good at 50 yards. When I go out to 100 it climbs, I was perplexed then remembered seeing ballistics charts where at closer distances the trajectory is listed as a negative ie.. -2.1 inches I pressume meaning the bullet actually climbs which is what I think my 240 XTP's are doing. I'd like to be flat out to 100, what do I do? Go up to a 300? I really don't want to go down in powder, I wanna keep the velocity up there.

cayugad 01-20-2007 06:22 PM

RE: Climbing trajectory
 
Sight in dead on at 100 yards. Then go back and check where the rifle hits at 50 yards, 25 yards, etc. I think you would be happy with that.

dmurphy317 01-20-2007 10:40 PM

RE: Climbing trajectory
 
"I'd like to be flat out to 100"

No bullet shoots dead flat, there is always some arc. Faster velocities will flatten out that arc but it will never be "flat", unless you can push it to light speed:).

Trajectory is what it's called and it's something that needs to be understood, especially by those of us that shoot frontstuffers at the velocities they work best at. What you may want to do is examine the point blank range (PBR) sight innumbers for the loads you are working with. I find this info helpful in understanding the limits of the load and then combine my personal limits with the loads limits to determine what is reasonable and feasable to expect of the load.

For instance, take your load of 95gr of powder and a 240gr bullet. Using 1750 as a velocity and .2 bc (these are just guesses for illustrative purposes) if you use a 2" PBR you sight in at 100 yards and your up 1" at 60 and down 1" at 115. For a 4" PBR you sight inat 122 and your up 2" at 75 and down 2" at 142. For a 6" PBR you sight in at 140 and your up 3" at 80 and down 3" at 164. Faster velocities will extend the spread of the numbers but will not make it a laser beam.

A little time studying trajectory charts helps a lot in visualizing what the bullet is doing (path wise) when it leaves the muzzle. I find this helps me in estimating hold over on longer shots as well as having the confidence to point and shoot when the target is within the PBR I'm setup for.

Good luck with your load.

Pglasgow 01-20-2007 11:18 PM

RE: Climbing trajectory
 

ORIGINAL: TXFRNTLDER

So I have a load of 95 grns. and the 240 grn XTP seems to be working pretty good at 50 yards. When I go out to 100 it climbs, I was perplexed then remembered seeing ballistics charts where at closer distances the trajectory is listed as a negative ie.. -2.1 inches I pressume meaning the bullet actually climbs which is what I think my 240 XTP's are doing. I'd like to be flat out to 100, what do I do? Go up to a 300? I really don't want to go down in powder, I wanna keep the velocity up there.
Do you have see through mounts on your scope? If so, your sight height is on the order of 2.25 inches. If so you'll be 2 3/4" high at 100 if you sight 2" high at 50. Take a ruler and measure the distance from bore center to the center of scope and use that number in the sight height field when running the ballistics program. Maybe that'll help?

TXFRNTLDER 01-21-2007 12:23 AM

RE: Climbing trajectory
 
Can't believe you guys didn't correct me on my mistake on the negative vs. positive on the shorter range trajectory.

TXFRNTLDER 01-21-2007 12:27 AM

RE: Climbing trajectory
 

ORIGINAL: dmurphy317

"I'd like to be flat out to 100"

No bullet shoots dead flat, there is always some arc. Faster velocities will flatten out that arc but it will never be "flat", unless you can push it to light speed:).
Yeah I do realize that, I'm just refering to the term flat shooting that is used for the higher velocitycalibers that do not have so much drop at short to moderate ranges.

Underclocked 01-21-2007 04:26 AM

RE: Climbing trajectory
 
Bullets don't climb.


Your trajectory curve is going to remain constant so long as your load remains constant. All you can do is vary the launch angle (line of bore).

TXFRNTLDER 01-21-2007 07:36 AM

RE: Climbing trajectory
 

ORIGINAL: Underclocked

Bullets don't climb.


Your trajectory curve is going to remain constant so long as your load remains constant. All you can do is vary the launch angle (line of bore).
Then this means you have TWO zero's on your scope? One close where the bullet shoots out relatively "flat" then again down range when the bullet comes back down?

The reason I ponder this is because I am dead on at 50 yards then high at 100. Maybey I am back to dead on on out at 150 175?

This has really peaked my interest and actually is inspiring me to spend more time on the range to tweak this in just right. All part of the fun.

MO Archer 01-21-2007 08:09 AM

RE: Climbing trajectory
 

ORIGINAL: TXFRNTLDER


ORIGINAL: Underclocked

Bullets don't climb.


Your trajectory curve is going to remain constant so long as your load remains constant. All you can do is vary the launch angle (line of bore).
Then this means you have TWO zero's on your scope? One close where the bullet shoots out relatively "flat" then again down range when the bullet comes back down?

The reason I ponder this is because I am dead on at 50 yards then high at 100. Maybey I am back to dead on on out at 150 175?

This has really peaked my interest and actually is inspiring me to spend more time on the range to tweak this in just right. All part of the fun.
No expert here....but if you sight it dead on at 100yds like stated earlier your 'two' zeros should theoretically be at your muzzle and at 100yds. Someone set me straight if this is way off.

lemoyne 01-21-2007 08:36 AM

RE: Climbing trajectory
 
MO Archer, If you are using a scope the bullet normally starts out at -1.5 inches crosses the line of sight at about 30yds depending on velocity and distance sighted in for"0" it will make a lot of differance if you are using irons, heavy loads and light bullets also make a differance. Sabotloader and several people have put charts up on here in the past some of them were recent youall might find it quite interesting to go back and study the differances load and bullet weight make. For example the comparision of the 50/40 200gr the 250 gr and the 300gr was suprising to me. Lee

MO Archer 01-21-2007 08:46 AM

RE: Climbing trajectory
 

ORIGINAL: lemoyne

MO Archer, If you are using a scope the bullet normally starts out at -1.5 inches crosses the line of sight at about 30yds deping on velocity and distance sighted in for"0"
This makes perfect sense. I should have thought about the differences for using a scope. Thanks.

txhunter58 01-21-2007 09:21 AM

RE: Climbing trajectory
 
Fact: the bullet begins dropping the instant it leaves the barrel.

Fact: The only way to get a bullet shooting "flatter" is to increase the velocity. The faster it moves, the further it gets "out there" before it drops more.

The difference you are talking about is determined by how high above the bore your line of sight is. In other words, an open sight is much closer to the line of the barrel than a high mounted scope. The lower the profile of the scope, the less of a "minus" figure your get at the muzzle and the less it has to "climb" (be pointed upwards) to initially reach your line of sight.

Said another way, the only way a bullet "climbs" is to be pointed upwards above your line of sight. This is trure even on the fastest magnum certerfire rifleout there.

Pglasgow 01-21-2007 10:18 AM

RE: Climbing trajectory
 

ORIGINAL: TXFRNTLDER
The reason I ponder this is because I am dead on at 50 yards then high at 100. Maybey I am back to dead on on out at 150 175?
TXFRNTLDER,

I'm not not doubting the POI prints, but it tells me that something is terribly wrong. There is NO WAY you can be "dead on" at 50 and "higher at 100" unless something is wrong. We know this, the laws of physics will not be violated. So something is wrong. Maybe your scope?

Underclocked 01-21-2007 10:20 AM

RE: Climbing trajectory
 


scope or irons - same principles apply.

txhunter58 01-21-2007 05:20 PM

RE: Climbing trajectory
 
Great schematic UC! A picture is worth......


All times are GMT -8. The time now is 11:02 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.