Let me respectfully add a bit to Chase1's comments. I have built Rem 700s into 338 Lapuas and its improved brother with no problems at all. I will not chamber a stainless steel M700 in any Lapua class chambering because the softer stainless steel will have more likelihood of having bolt lug set back issues.
The harder chrome moly steel does not have this problem when proper pressures are used in the Lapua. This brings us to the real reason I do not care to chamber the Rem 700s for the Lapua class chamberings.
The Lapua case will handle pressures far above what most if not all the other cases on the market will handle today. In fact, where a RUM case will start to loosen primer pockets at around 68,000 psi, the Lapua case simply similes and takes this pressure and even much more with ease.
This is where the problem comes in. If the 338 Lapua Improved is loaded to the correct 65 to 68,000 psi pressures, a chrome moly Rem 700 that is properly built should never have any problems. Its when a handloader tries to take the Lapua case to its limits like other case designs that they get into trouble because they are into pressure ranges far above what other case designs will handle but still not seeing any pressure signs at all.
Just to much of a liability issue in my professional opinion, that is why I stopped doing these conversions for customers......