07-17-2013, 07:41 PM
LRRPF52 Wrote:I'm getting a nice balance in performance from my 6.5 Grendel right now, and have been for the past 4 years. I have never mass-loaded any loads that showed signs of excessive pressure, and have been able to match factory velocities with 123gr pills.
A larger bolt would allow higher pressures, but at what performance gains? 100fps...200fps? It might make a difference for some of the guys running 6mm on the extreme end of performance requirements, but still won't get the Grendel up to speeds of the .260 Rem class guns, although it would be close IF you could squeeze out 200fps.
The .30 RAR is a whole different class of case, because it makes the AR15 a single-stack magazine, which would be fine for hunters.
I agree, a bigger bolt behind the PPC case is not the answer. You may gain 50fps if you are willing to push the performance. If you are worried about a flat primer or crater you wont load hotter anyway. If you want more performance like 200fps stepping up to a 6.5BRX would be the next move or buy an AR10 in 6.5x47 or Creedmoor.
I told the OP the receiver could be out of square, that is the only time I have seen an issue with newer bolts. One of the extension lugs could be damaged on the back side but I have never seen one.
ETA-If a receiver that has a tight bore like Vltor or Mega is used the extension is aligned by the diameter of the barrel extension, the front does not need to be squared. If the extension is sloppy in the bore like most receivers, squaring the front of the receiver doesn't hurt.