JusT wondering about rem700 receivers, does for example a std calibre and magnum calibre have the same same lower port dimension(width),
and then they simply use different dimension lip/magboxes to accomodate different cases (eg: 30/06 vs 300rum, 308win vs 300saum)....or do they also fasctory machine the lower port wider to accomodate the larger-fatter round?

They have different sizes and shapes. A 300 Rem short mag will not come anywhere close to even fitting through 223 feed rails.

The length can vary quite a bit too. The other day I saw a 700 in 221 Fireball, and about half of the receiver seemed to be filled in.

quote:

Originally posted by Trax:
JusT wondering about rem700 receivers, does for example a std calibre and magnum calibre have the same same lower port dimension(width),
and then they simply use different dimension lip/magboxes to accomodate different cases (eg: 30/06 vs 300rum, 308win vs 300saum)....or do they also fasctory machine the lower port wider to accomodate the larger-fatter round?

The 700 Remington actions are the same for the bottom opening of the receiver. The short action is different length opening from the 700 long action or the model seven action. The feed rails for the different cartridges will be machined specifically for that family of cartridges. The .223 and the .243 have the same length mag box opening with the .223 using a filler in the mag box. The .223 has a much smaller opening in the feed rails for the .222 family of cartridges. The short action ultra mag will have the same length mag box opening but the feed rails will be modified to accommodate the fatter cartridge case. I hope that clears things up for you because now I am confused. Really, I hope I answered your question.