The Redding Boss is a small-frame press having approximately a 4" frame opening and 3 1/2" ram stroke.
The Big Boss has a 4 1/2" frame opening and 3 13/16" ram stroke.
The Ultramag has a 4 3/4" frame opening and 4 1/8" ram stroke.
The T-7 Turret press has a 4 3/4" frame opening and 3 13/16" ram stroke.
The Big Boss is designed to handle the large magnum calibers. This is an excellent general-purpose press, and, if you choose it for your own, I believe you will be well pleased with its service. The T-7 Turret has similar capacity with the added convenience of keeping your dies permanently mounted. Similarly, the Hornady L-N-L bushings can be used with the Big Boss and Ultramag.