Are you griping and resting the bar on the palm/pads of the hands or are you resting the bar on the heel of the hands? Direct leverage on the heels of the hand reduces the stress on the wrist rather than setting the bar back towards the palm and gripping the bar that way (thumbs over the bar). Your going to have a false grip on the bar with the thumbs somewhat under, so apply caution at first if your not familar with this hand style of resting the bar on the heel of the hand. Hopefully you have alert spotters or are training in a power rack of some sorts. More power is generated this way, your pushing leverage is better.
300 is a good benching weight, don't let anyone tell you it's not. I find that some men, when beginning to get into heavier benching, will rest the bar on the heel of the hand by instinct. Tends to be too much wrist/forearm strain with the regular gripping style. Good Luck.