raising abv and sg reading

[alparvin08]

hello everyone I would like to thank everyone for the help and info on this site it has been a big help so far I am currently trying what i was told was a sweet feed moonshine mash and was trying to find info on raising abv and sg readings here is the ingredients i used
5 lbs cracked corn
1 lb malted barley
1 lb malted wheat
1 lb golden naked oats
5 lbs dextrose corn sugar
1 quart black strap molasses
6 gal distilled water
3 tsp alpha amylase

I ended up with a sg reading of 1.077 which is showing to come out at 10% abv I am wondering what i can do to raise the abv and any adjustments that might be needed i plan on using around 3 tsp red star dry active distillers yeast and around 6 tsp fermax yeast nutrient I know by adding sugar it will change the sg but what adjustments if any to the yeast would anyone recommend I would like to get to around 15% abv if this is possible again thank everyone for any input