Need help with understanding my groups

[CoHunter1991]

Question for shooting wizards . Factory ammo shot 1/2 MOA -3/4 for first half of the morning at like 30 degrees.

messed with the optic setting the zero caps and zero stop then shot another rifle . Shot the gun 30-45 min later and groups fell apart. 1.5 MOA

Temp had climbed to ~45 degrees but the ammo was in the shade the whole time. Velocity avg between the two sessions had also climbed 40 fps ….

Seekins element with NF Atacr on it. Chance I ****** the scope up setting the zero? I think it has to be ammo based or me. Let me know your thoughts.

Total shots were 26 shots :
11 in first set and 15 once shit fell apart.

Took a minute between each shot and barrel and suppressor were warm but not hot.

Thanks for the help

 

[RockAndSage]

This entire thread, read from the beginning, is some of the best info you can get on this:

Post in thread 'Cold bore zero versus (very) Hot bore zero “test”'

Nov 22, 2025

@Formidilosus , trying to get a really solid understanding of the key points you've made here in running these experiments, and explaining them. Trying to summarize them in a way that I can easily remember, and as I would explain to a new shooter with zero prior knowledge/bias/fudd-lore...

Would this be a fair translation?

• A gun's inherent accuracy is best discerned through establishing its "cone-of-fire".
• Establishing its cone-of-fire also needs to be done first, in order to properly zero the gun.
• Establishing a cone-of-fire is a volume event, with each shot being an...

• RockAndSage

• 

 

[CoHunter1991]

Thanks for pointing me to the thread and I’ll get reading. But just surface level looking at the worse groupings is it possible that the the slight increase in air temp caused the wide groups? Or is it likely my shooting?
Is an 1.5” cone at 50 yards normal for a good rifle?