6.5 Grendel PTG Reamer

[BjornF16]

I don't really know if this has any bearing on the subject but I am curious so I'll ask. Again back tracking to a few months ago and the short chamber issues with my McGowen barrel. I made a call to PTG and talked with Dave about my specific problem. Dave was aware of the problem and stated that the Grendel was a double throated reamer. Dave also said to use a .264 LBC reamer and that reamer works just fine and much better with the Hornady Grendel ammo because this reamer uses a parallel throat. What's the difference between a double throated reamer v/s a parallel throated reamer?

Instead of the Grendel double angle throat (0.5 deg which transitions to 1.5 deg), the LBC apparently uses a parallel free bore of .153" (constant .2645" diameter; Grendel uses 0.5 deg over this length) before transitioning to the 1.5 deg angle "forcing cone".

ETA: The LBC neck diameter is .295" vice Grendel .300"; LBC lead is .120" long at .2644" diameter; with a 1.5 deg throat. http://www.thefirearmblog.com/blog/2010/...del-clone/