Hmmm so you now know exactly what the problem is.................. Good
but let's face it the rifle should not be doing this
there is something not right here, very not right and I would be getting it sorted out pronto.
Oh yes differences in barrels and chambers can .......... can make a huge difference. I had a sporterised P-14 done by Century arms which had a chamber soooooooooooooo tight that no dies could resize a case to fit it. We tired 4 dies sets from 3 different makers
In the end I had it re-chambered for .303 Improved
Of course with this tight chamber pressures climbed quicker than a normal chamber. The other P-14 from century we had was fine and these had new barrels with 6 groove rifling fitted by Century.