HuntingNut
HuntingNut
   Login or Register
HomeCommunity ForumsPhoto AlbumsRegister
     
 

User Info

Welcome Anonymous


Membership:
Latest: RichardZ
New Today: 0
New Yesterday: 0
Overall: 13126

People Online:
Members: 0
Visitors: 140
BOT: 1
Total: 141
Who Is Where:
 Visitors:
01: Your Account
02: Forums
03: Forums
04: Home
05: Photo Albums
06: Forums
07: Home
08: Forums
09: Forums
10: Your Account
11: Forums
12: Forums
13: Forums
14: Forums
15: Forums
16: Forums
17: Photo Albums
18: Forums
19: Forums
20: Your Account
21: Home
22: Home
23: Forums
24: Home
25: Photo Albums
26: Your Account
27: Home
28: Home
29: Forums
30: Home
31: Forums
32: Forums
33: Forums
34: Home
35: Forums
36: Forums
37: Home
38: Home
39: Photo Albums
40: Forums
41: Forums
42: Your Account
43: Forums
44: Forums
45: Your Account
46: Forums
47: Forums
48: Forums
49: Home
50: Forums
51: Forums
52: Home
53: Photo Albums
54: Home
55: Photo Albums
56: Forums
57: Reloading Database
58: Forums
59: Your Account
60: Home
61: Forums
62: Forums
63: Forums
64: Forums
65: Home
66: Forums
67: Forums
68: Your Account
69: Forums
70: Photo Albums
71: Forums
72: Home
73: Your Account
74: Home
75: Forums
76: Your Account
77: Forums
78: Forums
79: Forums
80: Forums
81: Forums
82: Forums
83: Forums
84: Home
85: Forums
86: Statistics
87: Photo Albums
88: Forums
89: Home
90: Forums
91: Home
92: Forums
93: Home
94: Forums
95: Home
96: Forums
97: Forums
98: Photo Albums
99: Home
100: Home
101: Forums
102: Your Account
103: Your Account
104: Photo Albums
105: Home
106: Forums
107: Forums
108: Forums
109: Forums
110: Forums
111: Home
112: Forums
113: Forums
114: Forums
115: Photo Albums
116: Home
117: Forums
118: Forums
119: Forums
120: Forums
121: Forums
122: Home
123: Forums
124: Forums
125: Forums
126: Forums
127: Your Account
128: Home
129: Forums
130: Your Account
131: Your Account
132: Forums
133: Forums
134: Home
135: Forums
136: Photo Albums
137: Forums
138: Forums
139: Forums
140: Your Account
  BOT:
01: Home

Staff Online:

No staff members are online!
 

Coppermine Stats
Photo Albums
 Albums: 308
 Pictures: 2451
  · Views: 820725
  · Votes: 1316
  · Comments: 86
 

Negative sight heights?
Help / Support / How-to's / Discussion related to PointBlank Software and External Ballistics in general
Go to page 1, 2  Next
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » PointBlank Software

View previous topic :: View next topic  
Author Message
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Sat Jul 30, 2016 1:59 pm    Post subject: Negative sight heights? Reply with quote

I have a laser under the bore of one of my guns so I tried to enter a negative sight height to see what the trajectory might be. Didn't work, it automatically corrected it to a positive number. I'm not sure how many of us would use this feature but I thought I'd throw it out there.

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
PaulS
Super Member
Super Member


Joined: Feb 18, 2006
Posts: 4330
Location: South-Eastern Washington - the State

PostPosted: Sat Jul 30, 2016 5:32 pm    Post subject: Re: Negative sight heights? Reply with quote

There is always one guy doing something the programmer never thought would come up...

Nice going Pumpkinslinger! Smile
(if I had written the software it would have crashed, out of spite.

_________________
Paul
__________________
Speer, Lyman, Hodgdon, Sierra, and Hornady = reliable loading data
So and So's pages on the internet = NOT reliable loading data
Always check data against manuals
NEVER exceed maximum listed loads
Back to top
View user's profile Send e-mail
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Sat Jul 30, 2016 5:37 pm    Post subject: Re: Negative sight heights? Reply with quote

I try Paul!

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
Elvis
Super Member
Super Member


Joined: Jul 27, 2008
Posts: 9239
Location: south island New Zealand

PostPosted: Sat Jul 30, 2016 6:11 pm    Post subject: Re: Negative sight heights? Reply with quote

Pumpkin......... you can use that as a rangefinder of sorts. if you get lazer to intersect with cross hairs at a known distance,,,say 100 yards if beam/dot is below crosshair so is range and vice versa...works a treat on rifles.
as to your issue.......beats me why you would need it????? surely your scope is where you need the info for and dot is mearly to speed up process,aid in poor light???

_________________
You shot it You pluck it !
Them who eats the most duck eats the most feathers!
Back to top
View user's profile
PaulS
Super Member
Super Member


Joined: Feb 18, 2006
Posts: 4330
Location: South-Eastern Washington - the State

PostPosted: Sat Jul 30, 2016 6:13 pm    Post subject: Re: Negative sight heights? Reply with quote

And you are very good at it! Smile

a sight line lower than the barrel.... I think that will pose some unique situations.

_________________
Paul
__________________
Speer, Lyman, Hodgdon, Sierra, and Hornady = reliable loading data
So and So's pages on the internet = NOT reliable loading data
Always check data against manuals
NEVER exceed maximum listed loads
Back to top
View user's profile Send e-mail
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Sun Jul 31, 2016 2:26 pm    Post subject: Re: Negative sight heights? Reply with quote

The laser sits almost 3" below the centerline of the bore. The current sight is about 2.5" above the bore.

Elvis, I have a red dot sight. I looked and it's pretty hard to tell which dot is the sight and which is the laser! I'm looking for another sight that doesn't require a battery, but can be illuminated. So far I haven't made up my mind.

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
Elvis
Super Member
Super Member


Joined: Jul 27, 2008
Posts: 9239
Location: south island New Zealand

PostPosted: Sun Jul 31, 2016 10:21 pm    Post subject: Re: Negative sight heights? Reply with quote

maybe look for one with green illuminated reticle/dot...then there be no confusion
it works just as well from one side of scope too,eg if on left of cross hair under 100,right of it more than a hundy.as for your red dot...that's just got to be an issue in the making,sooner or later you will use wrong dot and go high or low.
the bit about them that really impressed me was out on edge of spotlight the beam helped illuminate a bunny rather well,making it easier to see in scope.

_________________
You shot it You pluck it !
Them who eats the most duck eats the most feathers!
Back to top
View user's profile
PaulS
Super Member
Super Member


Joined: Feb 18, 2006
Posts: 4330
Location: South-Eastern Washington - the State

PostPosted: Mon Aug 01, 2016 3:44 pm    Post subject: Re: Negative sight heights? Reply with quote

A straight line from under the bore is going to cross the line of fire exactly once. The trajectory of the bullet will be above that line except at the sight-in-range, and at all ranges longer, the trajectory will be increasingly below the line-of-sight. The deviation from the laser line will be exaggerated due to the line going up and the bullet falling faster at each yard.

Although the ballistics will remain constant the "line-of-sight" is at an angle away from the ground from below the bore line instead of more parallel from above the bore. The math may be similar but the results are going to be very weird.

_________________
Paul
__________________
Speer, Lyman, Hodgdon, Sierra, and Hornady = reliable loading data
So and So's pages on the internet = NOT reliable loading data
Always check data against manuals
NEVER exceed maximum listed loads
Back to top
View user's profile Send e-mail
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Mon Aug 01, 2016 11:35 pm    Post subject: Re: Negative sight heights? Reply with quote

Paul, yep, that's why I was hoping to see the trajectory "on paper".

I ordered this to stick on the carbine. It has an etched reticle so it will work without a battery. And it has the option of red or green illumination.

www.midwayusa.com/prod...icle-matte

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
PaulS
Super Member
Super Member


Joined: Feb 18, 2006
Posts: 4330
Location: South-Eastern Washington - the State

PostPosted: Tue Aug 02, 2016 6:47 pm    Post subject: Re: Negative sight heights? Reply with quote

Well if you mount that under your barrel you won't be able to use it ! Shocked Cool Laughing

_________________
Paul
__________________
Speer, Lyman, Hodgdon, Sierra, and Hornady = reliable loading data
So and So's pages on the internet = NOT reliable loading data
Always check data against manuals
NEVER exceed maximum listed loads
Back to top
View user's profile Send e-mail
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Tue Aug 02, 2016 8:46 pm    Post subject: Re: Negative sight heights? Reply with quote

I'll just hold the gun upside down like Jerry Miculek!

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Fri Sep 02, 2016 12:36 am    Post subject: Re: Negative sight heights? Reply with quote

Sooo... No negative sight heights?

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
slimjim
Super Member
Super Member


Joined: May 16, 2009
Posts: 8314
Location: Fort Worth TX

PostPosted: Fri Sep 02, 2016 5:36 am    Post subject: Re: Negative sight heights? Reply with quote

Pkslinger, here is an on-line cal that does negative sight height. I tried a couple before I found it as most only did positive.

www.jbmballistics.com/...aj-5.1.cgi

Wouldn't a green laser be better for your situation as it would be brighter and be more usable during daylight?

_________________
"To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt

"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein
Back to top
View user's profile Photo Gallery
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Fri Sep 02, 2016 6:26 am    Post subject: Re: Negative sight heights? Reply with quote

Thanks Slim!

Yes, green would be better in daylight but red was a LOT cheaper...

At this point I think I'll zero the prismatic sight at 100 yards and the laser at 25 yards. We'll see if this works in actual practice. I've got a few days off here and may actually get to go to the range!

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
Pumpkinslinger
Super Member
Super Member


Joined: Sep 22, 2007
Posts: 5001
Location: NC foothills

PostPosted: Fri Sep 02, 2016 6:35 am    Post subject: Re: Negative sight heights? Reply with quote

I stand corrected!!! I just went back and played with PointBlank again. I entered a negative sight height and it worked fine! Maybe I fat fingered something before...

The trajectory looks odd but revealing! I'm now thinking maybe a 50 yard zero for the laser.

_________________
Mike

"I ain't no better than anybody else, and there ain't nobody better than me!" Ma Kettle
Back to top
View user's profile AIM Address Yahoo Messenger Photo Gallery
Display posts from previous:   
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » PointBlank Software
Page 1 of 2
All times are GMT - 7 Hours
Go to page 1, 2  Next



Jump to:  


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Valid CSS! Valid HTML 4.01!
Click to check if this page is realy HTML 4.01 compliant for speed :)

All logos and trademarks in this site are property of HuntingNut.com.
The comments are property of their posters, all the rest © 2011 by HuntingNut.com
Interactive software released under GNU GPL, Code Credits, Privacy Policy

.: Upgraded to DragonFly 9.2 by *Dizfunkshunal* :.