ANyone know BC for a Lyman mold I have

[wiliamr]

Does anyone have the BC for the Lyman 457677 mold? Mine are coming out at 489 - 490 and they sure are pretty accurate. Need the BC to develop Balistic chart. Thanks

[Larry Gibson]

457677 or 457671?

Larry Gibson

[bishopgrandpa]

457671 is one showing in manual at BC.477

[Firebricker]

I can't find that mould in the cast handbook. FB

[wiliamr]

It is a PaulMathews Schmittzer. 457677 designed to be a bore rider first three rings are .450 to .451, last 3 rings run .457, .458 and .459 Shoots amazingly well over 70 grs of Swiss 1 1/2 FG It shows up in Lymans web sight

[Firebricker]

Williamr, Sorry I was no help but welcome to the forum ! FB

[wiliamr]

Thanks, been here for long time, had to redo my login. As far as help, just offing help is more than anything.... I have been playing with some tables and some old BC stuff and am leaning to calling this bullet a .461. My avg vel with BP is 1242 sooo perhaps I should buy another chrono and see if I can get two vels.... Oh my.. I retire in 15 days, and while 20K loss in income is stiff, well another chrony is a NEED!

[armedmoose]

If you have a chrono I would just put it down range.. using your known data for Muzzle velocity and work out your Ballistic coefficient. Save from buying a second chrono, if that is what you meant.

A calculator if you dont have one already to compute coefficient:
http://www.jbmballistics.com/cgi-bin/jbmbcv-5.1.cgi

And a Ballistic Calculator I like once you have your coefficient:
http://www.hornady.com/ballistics-resource/ballistics-calculator