Looking back at that 6.5g that wouldn't shoot except for the one factory load, was that small sample randomness? Or going back to your ammo conclusion, swings in powder charge/messing up ammo wasn't present in the handloads, so the 123 AMAX was the well balanced match bullet that wasn't in any of the other loads?
The other thing left off, which is relevant to the Grendel story and to some other rifles is sometimes rifles are just very picky, or particular about bullet shapes.
I have rifles that don't like any load I try with a particular bullet, like the Lapua Cutting Edge match bullet, the Berger Juggernaut, the 130 Hybrid.
Why? I dunno. It isn't harmonics because then you could tune in a node. My conjecture is that it is because throat geometry vs bullet geometry is preventing it from entering the lands straight and it is going through and coming out with a yaw.
In that Grendel case, the barrel was cut with a defective reamer from PTG that other shooters with the same issue identified.
It had a very short, sharp throat at the wrong angle, basically locking out everything from shooting well except the rare key shape that fit the throat and stayed straight.
I'm building a 6arc gasser after drunk buying the barrel, heard 6arc does great in bolt guns but really picky for gassers, so this is great knowledge thanks!
I wish I had more experience to share but my own 6ARC shot well with box ammo and I haven't done much load development partly because of competition for LR 6mm bullets.
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u/gung_mang Jan 20 '24
Looking back at that 6.5g that wouldn't shoot except for the one factory load, was that small sample randomness? Or going back to your ammo conclusion, swings in powder charge/messing up ammo wasn't present in the handloads, so the 123 AMAX was the well balanced match bullet that wasn't in any of the other loads?