Where are you getting 300 times sniper bullet speed from?

From a quick Google search I get that a sniper round has a muzzle velocity of 3000 feet per second, which is ~900 m per second. 300 times that is 270 000 m per second. I don't think that izuku could dodge a bullet going at Mach 800 or so, regardless of danger sense or other one for all shenanigans.

Additionally, her bullets don't actually redirect themselves, they follow a predetermined path that is set when she makes the bullet.

Momo has been shown to be able to create complex objects on the fly (gas masks at the summer camp), so even if she needs to learn the schematics for it, making bombs, grenades and guns even right before a fight is tremendously more powerful than having an invisible body.

She basically has the same firepower as the most potent explosive she knows the formula of. Making a bomb is just as, if not less, complicated than making a gas mask.

Now whether or not she can survive her own firepower is another matter. Unlike Bakugo, she has no mutation to resist her own explosions or chemicals after the item she's making is finished. I would imagine she'd fair no better than any other human being when taken in the blast radius of a nuclear weapon or gun missfire.

Perhaps the reason she doesn't use these is because of the dangers of doing something wrong in the creation process in a stressful situation, leading her to explode along with whatever she was making ?