I'm guessing that must be an 1885 because I don't think they ever chambered the B78 in 270. You have a better chance of getting a decent trigger with one of those.
Jerry
According to Wikipedia :
Browning B-78. First built in 1973 and discontinued in 1983, this single shot rifle was initially offered in .22-250, 6 mm Remington, .25-06, and .30-06. .243 and 7mm Rem Mag was added to the standard rifle line and a .45-70 version was added on a heavier frame.
According to this it never came in .270. Funny thing is i thought it did. Silly me.
Paul B.