Wandering zero, scope or could be something else?

[st1650]

So before I send Vortex *another* scope back just weeks before deer season I thought I'd ask here first.

300 BLK Defiance AnTI, Bartlein 1:8 prefit barrel. Shot great this spring, easy 3/4 moa on Speer 150 gr and even sub moa with the lighter 110 VMAX, 110 & 120gr TAC-TX.

Now coming closer to hunting season I started noticing weird weird stuff. So I thought I'd go with elimination process. Remove the muzzle brake, removed the Hawkins direct mounts and replaced them with a picatinny rail and ATRS rings. Still getting wandering zero. For example rifle is zero. A week later I go to the range and I'm low 1 mil and right 1 mil. And even correcting windage on the turret 1mil, I'm still right 1 mil until at some point the group magically starts getting tight and hitting POI/POA then the next week (or 1 hour later) it's all over the place again. The chassis is torque to 65in/lbs. Scope top rings torqued to 18-20in/lbs. It's not my first rodeo and it's not like 300BLK is a monster that incredibly hard to shoot. It just baffle me because I'll drill a 5 rounds 3/4 moa with subsonic 208 amax at 100 yards and then the next shot will barely be on paper and I know my hand loads are fairly consistent (ES of 10-15 FPS). So could it be anything else but the scope at that point ? I've never had a rifle that would not shoot consistently and it's making me question everything (handloads, shooting technique, bad barrel, bad chamber ?)

 

[nn8734]

Put a known good scope on it and shoot it. that should rule in or out the current scope.

Which vortex do you have on there now?

Viper gen2s and Razors are generally reliable, their chink stuff not so much.

Like anything else, You get what you pay for with optics. Hooe you get it sorted. If it gors back to vortex, dump it as soon it’s back in your possession and buy a better (Non-Vortex) optic.

 

[st1650]

It's a Razor LHT HD 3-15x42. I swore off all PST and non Razor since I never had one that lasted but yeah I do have a Bushnell HDMR II that's an absolute tank and I'd take it back and forth +/- 20 mils on my RimX and always had absolute return to zero. The only downside is it's a FFP and not the greatest reticle for low-light in fall but hopefully I can rule out the barrel or picatinny mount.

 

[nn8734]

It's a Razor LHT HD 3-15x42. I swore off all PST and non Razor since I never had one that lasted but yeah I do have a Bushnell HDMR II that's an absolute tank and I'd take it back and forth +/- 20 mils on my RimX and always had absolute return to zero. The only downside is it's a FFP and not the greatest reticle for low-light in fall but hopefully I can rule out the barrel or picatinny mount.

Put the Bushnell on the rifle. Then follow the rest of my suggestions above.