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View Full Version : Lyman sight info in cast book



Harpman
08-27-2006, 02:21 PM
I about done all I can do at 100 yards, I have an excellent load and getting my stuff together for long range...you guys know if the info in the back of Lymans cast bullet book, sight adjustment, elevation drop and windage is a very good start as a reference with a Lee Shaver sight setup..figuring their drop and adjust with moa on the sight. or maybe there is an easier or better way to start getting on target...

montana_charlie
08-27-2006, 09:04 PM
I don't have that book available, so I have no idea of the information provided.
I take it that you have a load that is consistently accurate at 100 yards.

I suppose you know the ballistic coefficient of your bullet, your muzzle velocity, and bullet weight.
If so, you can try one of the ballistics calculators to get an idea of how much drop you can expect at longer ranges...so you can estimate sight settings needed for your particular load.

A ballistic coefficient calculator:
http://www.uslink.net/~tom1/calcbc/calcbc.htm#calculator

Ballistics calculators:
http://www.handloads.com/calc/
http://www.norma.cc/htm_files/javapagee.htm (click on the photo)

CM

Harpman
08-27-2006, 09:42 PM
Thanks...yea, I got all that info..this final load is doing one hole at 100..consistantly....using wheel weights at a BHN of 10.4....seems every batch I make comes out 10-11 bhn

montana_charlie
08-27-2006, 09:46 PM
Is that .45-70 from your Pedersoli?

Harpman
08-27-2006, 09:53 PM
yea ...I been working at it for about 90 days, finally got it constant...it appears the OAL was the most important factor in this load along with amount of barrel friction. right at 1160 FPS.

joeb33050
08-28-2006, 01:35 PM
If you tell me the ballistic coefficient I'll tell you the sight settings at various ranges.
joe b.

Harpman
08-28-2006, 02:59 PM
Thanks......well, I thought I had it..its the Lyman postell 457132...weigh 535, 1160FPS..my zero (o) bottom line,..on the elevator part is set at the 3rd moa on the staff..set for 100 yards.

montana_charlie
08-28-2006, 11:35 PM
my zero (o) bottom line,..on the elevator part is set at the 3rd moa on the staff..set for 100 yards.
I can't picture the setting you describe.
If you have a vernier scale, there are either five or six marks on the slide ('elevator part').

If the fourth mark from the bottom on your slide is matched to the fourth mark (third mark up from the -0- line) on the staff. That would be 'three minutes' (or 'points').

If the bottom line on your slide is matched to the fourth mark on your staff, that would be 'fifteen minutes'.
I have a pretty tall front sight, so my rifle is zeroed at 100 yards when my tang vernier reads '18 points' (MOA).

Here are instructions (http://www.montanavintagearms.com/vernier_instructions.html) for reading a vernier sight scale. From that, tell us how many minutes of angle you are reading when zeroed at 100.
CM

Harpman
08-28-2006, 11:38 PM
Thanks Charlie, I am at 15 minutes

montana_charlie
08-29-2006, 12:28 AM
OK, figuring your bullet's BC at .375 (rough but close estimate) it looks like you would add about 14 points to be zeroed for 200...or add about 30 (to your hundred yard setting) for 300.
(These are based on data from one of those ballistics calculators I posted links to.)

You didn't actually say what range you want to try next.
CM

Harpman
08-29-2006, 04:06 PM
I appreciate you taking the time Charlie...I am going out to a friends property and set up targets from 100-1,000 yards..but 2&300 will keep me busy for awhile..

Harpman
09-11-2006, 02:32 PM
I finally got out to test at longer range, Charlie your numbers had me on paper, THANKS...I got her shooting 8 inches at 400 yards, with that being my first shots past 100 yards in 30 years, and it being windy too..I am happy with the groups..this is a good starting point, I'm sure it will get much better.

Black Prince
09-29-2006, 11:47 AM
And THANKS Charlie for that information on the sight settings. I have been guessing about that and I have been guessing wrong. Dang it's good to be here on this forum with you boys who actually KNOW what you are doing!!