Not ever in a cold barrel. One variation we tried showed that things are very nearly there but not quite.
Not being one to accept whatever comes my way, I'm seriously into developing a jacket that will work in 'my' barrel.
Corbin makes dual inside diameter jackets. But when reduced to .277 from 30 Cal I think that 'something' happens.
I'm bumming time on every lathe in town to get the final configuration and talking with PTG about a reamer/drill to produce the inside dimensions that are needed.
However, that will take some time as once accuracy is achieved then terminal performance will need to be verified. (There won't be a safe lama, burro, or jersey cow in the county
Once all of this gets worked out, then Wildcat will make the bullets.
Additionally Paul @ Wildcat is working on some stuff. I expect some samples as soon as those that are HOARDING 7mm stuff get their bellies full.