Same Ammo, two different rifles, one blows holes in the primer????

[teenahlake]

If you use the same ammo in different rifles with the same barrel length, wouldn't the pressures be the same? If both barrels are sized for 7.62 are they not basically identical excluding length? What I'm getting at is, if this ammo doesn't have excess pressure in other rifles then why would it have excess pressure in mine?

A minimum spec chamber can cause pressure to rise, leade length varies too, even the same bbl 1500 rds later will have a longer leade, and lower pressure/velocity. no two rifles are the same