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bruce drake
01-20-2020, 11:59 PM
I'm looking for some Ballistic coefficient values for the following three molds that have been discontinued by Lyman and are no longer in their product catalogs

6.5mm
Ideal 266305 - a 105gr gas-checked round nose design for small game or plinker 6.5 cartidge loads. I use it in my 6.5Grendel and 6.5x50 Arisaka rifles.
Ideal 266455 - a 130gr gas checked round nose design that was brought out for Post WWII 6.5 Arisaka and 6.5 M-S war bringbacks and surplus rifles.

8mm
Ideal 323366 - a 185gr gas-checked Spitzer copy of the WWI German 190gr 7.92x57 FMJ bullet with a steel core.

Using a free online BC program that limited my input of data on the diameter of the bullets at .26 and .32 respectively, I came out at external BCs for the bullets at: .366; .452 and .507 for the three and because of the 2 digit caliber entry, I'm not trusting their actual value matching up to the real bullets.

granted, I'm not looking to shoot any of the three past 300 yards but I would like to be able to accurately predict their drop tables before I head to the ranges this spring to test theory with practical application of the bullets to targets.

And here is a blast from the past, while I'm typing this request on my new Dell Laptop that uses Windows 10 for my internet work. While in my reloading room, my shooting data is still being inputted into a DOS6.22/Win3.11 based computer because I still enjoy using LEE Precision's 1980's era DOS-Based SHOOTER software program and where I have all the BCs for all my other RCBS, Lyman and LEE molds already inputted into the bullet database. Using it, I can print out my drop tables for my load sheets based off velocity, bullet weight and BC values and it usually puts me on paper for elevation quite easily.

So....does anyone have a listing of BCs from Lyman/Ideal on these three particular boolits as there are not listed in Lymans's loading guide or cast bullet manuals either?

Bruce

Ford SD
01-21-2020, 01:21 AM
I would go to NOE and other mould makers, some of them make copies of the older moulds and list BC
Noe lists BC on there drawing/ dimension page

Nueces
01-21-2020, 09:14 AM
One of the earlier Lyman Cast Bullet Handbooks, either edition 2 or 3, edited by Ken Ramage, has a final section listing their measured BCs, from chronograph data, for all their designs at the time of publication. The technical notes are also interesting.

bruce drake
01-21-2020, 08:25 PM
One of the earlier Lyman Cast Bullet Handbooks, either edition 2 or 3, edited by Ken Ramage, has a final section listing their measured BCs, from chronograph data, for all their designs at the time of publication. The technical notes are also interesting.

Nueces,

I have the Lyman 3rd edition and those molds aren't listed. I'll try to find a pdf copy of the older 2nd edition.

Bruce

bruce drake
01-21-2020, 08:27 PM
I'll go to NOE and see. Mountain mold's new site doesn't list 6.5 molds anymore and he doesn't cut molds to copy that 8mm mold profile so his design software is not available on those three.

Bruce

Larry Gibson
01-21-2020, 08:37 PM
The measured (Oehler M43 PBL) BC of the Lyman 266455 out of a 6.5 Swede runs .255 - .259.

bruce drake
01-21-2020, 10:01 PM
No luck with NOE as well. They don't have equivalent molds (to be honest they are specialty use or long-out of production molds.) I will measure the bullets out and try to use another online BC calculator to get a more refined BC than just their 26 and 32 caliber bullet status.

Tom Myers
01-22-2020, 12:15 PM
Bruce,

Kind of a slow morning so I decided to see what the Precision Shooting Software modules could do to provide some information for you.

BCs can be estimated fairly closely from bullet profile and weight. I managed to locate various images of the bullets in question and proceeded to scale up dimensions for the bullets.

The Precision Cast Bullet Design and Evaluation 5 ~ Advanced (http://www.tmtpages.com/#Advanced) was used to construct visual images and calculate estimated BCs and

The G1 Ballistic Coefficient Estimator (http://www.tmtpages.com/New_G1BC/cast_bc.htm) uses a slightly different algorithm for BC estimations

Enclosed are screen snaps of the various images for your consideration.


Lyman, Ideal 266305

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman_266305_(Scaled).Jpg

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman_266305_(Scaled)_103_gr_Sketch.Jpg

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman_266305_(Scaled)-BC.Jpg

Lyman/Ideal 266455

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman_266455_(Scaled).Jpg

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman_266455_(Scaled)_129_gr_Sketch.Jpg

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman%20266455-BC.JPG


Lyman/Ideal 323366

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman_323366.Jpg http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Ideal-308329-30-Caliber-Springfield-Single-Cavity-Bullet.jpg

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman_323366_(Scaled)_182_gr_Sketch.Jpg

http://www.tmtpages.com/LinkSkyImages/forum_images/BC_Calcs/Lyman_323366_(Scaled)_.Jpg


Hope this helps.

bruce drake
01-22-2020, 08:51 PM
You Sir! Are truly a Scholar and a Gentleman of The Finest Order! And quite a Knight as well!

And I am now going to have to go see your software website as that informational screen shots were exactly the information I needed (and perhaps even have me advance to this century in ballistic software and finally retire my ported DOS-era LEE SHOOTER program as well)

bruce drake
01-22-2020, 08:57 PM
The measured (Oehler M43 PBL) BC of the Lyman 266455 out of a 6.5 Swede runs .255 - .259.

You and Tom's software results are nearly equal!

bruce drake
01-22-2020, 08:58 PM
Yes indeed! Your software apps are now on my "to be purchased " list!

Correction, Your ballistics software is on my purchased list. Happy Birthday to me! ;)