Swedish Mauser

Can I fire bullet variations within a rifle as long as its the same caliber? EX: 6.5x55mm in a 6.5x50mm gun.?

I have a Japanese 6.5x50mm Arisaka rifle, and was wondering if Swedish 6.5, 6.5 Mauser, or other 6.5mm (.264)cartridges would be operational, or if bullet grain and cartridge length must be taken into account.

NO
cartridge dimensions are critical
NEVER fire a cartridge in a firearm that is not specifically chambered for it
it is quite possible it will blow up and injure or kill you or anyone nearby
there are a few exceptions – primarily in revolvers
.38 special can be fired in .357 magnum but not reverse (same for .44s)
if you do not KNOW – don’t assume – it can kill you

M96 Swedish Mauser 6.5X55