The explorer reported 63m at 4.8g/t gold from 357m, including 2m at 31.1g/t.
"The systematic drilling we are doing below the pit bottom has, to date, yielded exceptionally robust results," chairman Jim Sinclair said.
Highlights from in-pit drilling last month included 29.6m at 2.8g/t from 81.5m, with the company noting many of the intersections were "significantly higher" than the weighted gold grade of 1.5g/t for the pit.
The company filed an amended report for the project last year, based on reserves of 19 million tonnes grading 1.54g/t gold.
The prefeasibility study outlined initial capex of US$76.5 million for a 16-year operation from four openpits, with an after-tax NPV (5% discount) of $130.96 million and an IRR of 74%.
Buckreef was expected to produce an average 51,000oz a year with a gravity/CIL plant slated to yield recoveries of 92.3% and 85% for the oxides and sulphides material respectively.
Tanzanian Gold has the right to earn 55% of the previously-mined project from the Tanzanian State Mining Company, which holds the remainder, under a deal struck in 2010.
It was served an eviction order from its Kigosi base camp recently after "many years of disputed access" and in line with the area being designated as a game reserve, which TNX said was contradictory to its long-held Kigosi mining licence.
It relocated equipment and drill cores to Buckreef and said in its latest MD&A it was continuing to work with all stakeholders to bring the matter to a mutually beneficial resolution.
The company, which is also listed on NYSE American, changed name from Tanzanian Royalty Exploration in April.
It raised more than C$1.5 million last month at 66.09c per share and also announced plans to raise up to US$3 million stateside with shares to be sold "at the market prices prevailing at the time of sale".
It plans to use the proceeds to advance Buckreef, for working capital and general corporate purposes.
Its shares are up three-fold in Toronto this year, trading at C33.5c in January, before rising to $1.32 in April and last trading at 95c, to capitalise it at $131 million.