Some Savage prefits are not long enough to thread into a Savage action far enough to headspace, because the Barloc requires a little more room than is threaded. I first heard this about a Proof prefit. That person had to use the standard recoil lug instead of the one that comes with the Barloc. I have a Savage Barloc as well, and my Criterion barrels are not threaded enough to allow use with the Barloc on a Savage action. Interestingly, my factory Savage barrels have just enough threads to use the Barloc.
I ordered the Nucleus, and I am hoping that the Barloc will work with the Criterion and other barrels.
If not, I hope that PVA and others figure this out and just give a little more threads on the prefits to use the Barloc. Otherwise, it isn't going to work out as well as hoped for me.