.444 marlin, cases

I just built a rem. r.b. in this and started to prep some brass. have 2 kinds, rem. and hornady (from factory ammo). the hornady is almost .2" shorter than the rem.[xx(]. I'll guess this is so they can get a crimp in the 'lever revolution' bullet without going over oal. kinda like shooting .44 specials in a .44 mag.