You may have to contact McM to see if they will do a stock with edge fill to get below 24oz.
I've used a few T3 stocks over the years and this is what they weighed:
1. T3 factory plastic - 29oz
2. T3 factory wood - 30oz
3. T3 B&C - 35 to 36oz
4. T3 Wild Dog carbon fiber -
27oz- See pic below