JASmith Wrote:I did a quick perusal of the JBM length tables (http://www.jbmballistics.com/ballistics/...gths.shtml) and found several in the range of 5.4<L/D<5.8 so it would appear that L/D = 5 is not a hard limit.Okay, but don't forget the tracer.

Tracer projectiles (for rifle/m.g. cartridges) are nearly always -- if not always -- signifcantly longer than ball bullets. If you make the ball round 5.8 L/D, what will a matching tracer be? 6.8? 7.8?
Another thing to consider: Bullets of <5.0 L/D already eat up substantial powder volume in the Grendel case.
![[Image: 65Grendelx300.jpg]](http://www.6mmbr.citymaker.com/i/Products/65Grendelx300.jpg)
Increase L/D to 5.4-5.8 and capacity will be cut even more.
