6.5 Grendel PTG Reamer

[JASmith]

...he was going to do what people ask for and make free-bore for heavier bullets. Not sure if it will accommodate the 123gr to 129 or 140 but we'll see. PTG is currently making the reamer, its in process. I will not have them deviate from the original since I do not know if the material being removed will open it up and once the barrel is heated up, will it become less accurate? That is an unknown to me. I know Steve would not do what he is doing if he felt there was a compromise but I'm satisfied with the way it is.

Your barrel will be in good hands and I think this entire issue got out of hand but now the Grendel II will handle heavier bullets from the get go and make everyone happy...

The SAAMI-standard Grendel chamber handles heavy bullets just fine already. Check Lapua's load data (on line and in Volume 1) and you will see that the heavier bullets are all seated at reasonably normal lengths. In fact, the 156 grain Mega is seated to 2.260 inches.

We have heard several statements to the effect that the reamer in question was cut to the SAAMI line with a plus and minus .001" tolerance. If this interpretation is correct, this makes, one average, half of the reamers out of spec on the tight side. Why? The SAAMI spec is minus .000 and plus .002" so the spread is right, but the datum is too tight by .001" and will get tighter with wear and resharpening.

The confusion is easily to understand those of us who might not be intimately familiar with SAAMI standards.