It is my experience with the JMF Shofield Collection my first generation were Standard sized. I have a couple birds that weigh in the 9 ounce range. I am currently breeding My Silver over other colors including my Jumbo Browns to improve egg and bird size. By crossing the Silvers over other colors I am getting approximately 50% Silver chicks and it appears to improve their over all vigor. My Oldest chicks are only 4 weeks old so I don't have mature weight on them yet. I am having lots of fun playing with this color variety and look forward to my second generation Silvers becoming mature and entering the breeding pens.
Below is a collage of a few of our Shofield Collection Silvers and our first 2 home bred babies.