The Bretton had French proofed, aluminum barrels. You didn't need screw in chokes, as the barrels were screw in.

Geno, both the MIG 29 and the SR-71 used titanium in construction. Can't speak for the MIG, but, the "Blackbird" was one of the safest airframe and flight programs ever put to use-none were lost operationally, although several countries tried.

The South China sea has a fair amount of titanium littering it, from SR-71s that crashed after repair while in testing.
Best,
Ted