.243 vs .243

[the blur]

I have (2) .243 rifles. Mossberg ATR & Browning BAR. Both have 1:10 twist.
The Mossberg loves 58gr varmint ammo, and won't group with heavier ammo.
The BAR loves 90gr Nosler ammo, amazing deer rifle.

Why 2 guns, same twist rate, different weight ammo works in 1, but not the other ????

 

[coop2564]

All about barrel and harmonics. You can have 2 guns of same make and twist and have them not shoot same bullets equally.