Ours (Walks Alone) came pretty reasonably sized as far as weight from smooth shouldered angus cows, but the calves had some shoulders and were built like bricks. These were 5th calvers that had no birthweight issues on previous calves. I would wait for a 3rd calver.
Iwouldn't breed him to anything less than a third calver,BW really isn't the issue,all mine are reasonably sized,the're just biult like rockstars when they are born.