What makes one better then the others?
Mauser 98, Ruger M77 or Rem. 700 action for custom build

That question is a little to vague to answer properly. It would depend on what the end goal was. Just as one of many "for instances"...If I was building a bench gun(depending on the type of competition), I might chose the 700, on the other hand if it was a hunting/field rifle I would lean towards the M98(depending on what action/caliber/type of hunting, ect.). I think you might get more responses if you narrowed the question down a bit.

Colin

The Eye of the beholder.

Everyone has an opinion, form and function plays a part, precision fitting of all parts also plays into it but then again sometimes you get lucky and one will just shoot . This is where opinions come from. With due efforts and quality to match grade parts a good smith can make almost any rifle shoot, sometimes a great deal of money is required to make this happen as quality is not cheap, now out of the box guns ,you take your chances, most are capable of of shooting better than the owner with propper ammo it likes and a little tuneing, one hole guns are almost nonexcestant except in the hands of the very best shots, beautiful wood makes for more expense but also increases the I want it factor so I guess I am trying to say there proably is no overall best just a neverending search for it. All the best James

What makes one better than the others?

It's like asking which is better, blonde, brunette or redhead? (It's redhead, by the way)

It's all personal preference.

How tall is your stack of money?

Get a CZ550 or CZ550M and avoid the stress of indecision, conflict of opinion and have the best and most affordable platform for a bolt action custom build.

I have several CZ 550's and they do shoot well.
But now I need a SWEET 6.5x55 or 257r

The Mauser 98 is better, becuase I say it is!