Yes, about 25 years ago, in both .223/.22LR and .308/.32ACP.

Accuracy was awful - 'Minute of minivan'.

George

George is right about the accuracy.

But, here is a suggestion.

We made our own by cutting down a barrel, turn it down, and profile the end to fit the chamber of the rifle we wanted to use it in.

We made one for a Ruger #1 which started life as a 458 Winchester Magnum, and we had re-chambered for the 460 Weatherby Magnum.

We made an adaptor for the 223 to fit it - left the insert at 14", and shot well.