</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Dwight Gruber:
<strong>Waitaminute, have I been misinformed all my life, or did we just enter an alternate universe? The "total bore diameter" is land-to-land, is it not?, with rifling depth (groove diameter) being solely an engineering/design consideration, not having anything itself to do with the caliber designation...
--Dwight</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Hi Dwight!!!
Caliber is measured from land to land, in the UK and US anyway. In Europe, the designation is from groove to groove. The 9MM Parabellum is measured from groove to groove, as the bullet is 9MMs in diameter.
No, I don't think that you have entered a new universe quite yet. Ha!!
A cast lead bullet must fit snugly against the groove to assure premium accuracy. Without a snug fit, the soft lead bullet can simply strip over the rifling, thus yielding very poor accuracy.
The actual reason for my question is that I am designing a truncated cone bullet, just like the DWM original military bullet, except of cast lead. To yield maximum accuracy, they must fit the groove of the Luger properly.
Bob
|