Certainly. Most gunsmiths using a 700 will start a custom build by truing/blueprinting it so everything fits correctly.Is a Rem 700 SPS action(blued) sufficient for a custom made gun?
Not even close to always. It's probably the most used factory action, but I don't know if it's the most used action for custom builds. Savage actions are used often, as are Weatherby, Browning, etc. Many custom rifles are built on custom actions, too. There are many from many makers, each designed for a different use/niche. Here's a list and a short review of each.Are custom made guns usually/always built on 700 actions?
It's probably the most used factory action by professional gunsmiths. There are a boatload of DIYers that build ground up custom rifles on Mausers and Savages because it is so easy compared to a 700.It's probably the most used factory action, but I don't know if it's the most used action for custom builds.