Barred Plymouth Rock in current stock are notoriously slow to mature. They never were speedy but over a hundred years from origin and these have gotten worse. White Plymouth would be a better choice. It's the best variety of that breed. White birds will present better table bird. Dark pin...
Not to hyjack the thread but if anyone is working on utility breeds or hybrids or projects to sustainable meat birds come on over and post what you have/are working on and your goal in a thread just started...
Of course there is always making your own hybrids. Running two separate breeds and doing a cross once a year for a hybrid meat bird. That would prove a little better than a pure standard bred bird. Fastest maturing standard bred now is New Hampshire. Common broiler hybrid before CornishX was...
Ridgrunner makes some very good points. Are you good with a bird that reaches 3- 3.5 lbs dressed weight at 12 weeks? If not then it's looking like there is no standard bred bird out there left that performs better than that. Once you get past 14 weeks the age for broiling or grilling are over...