The piggy back system is a upgrade that RCBS came out with to upgrade a RockChucker or RL3 single stage press to a 5 station progressive press.
There was a Piggy back 1, PB2, PB3 or PG4. The Piggy Back 3 and 4 are essentially the same machine. One is used for the new Rock Chucker extreme that has a longer throw. So needs a longer ram.
In my opinion for guys that want to use a older press. The PB2 is the best one to get. It can be upgraded some. Plus it has a positive lock on the shell plate.
I use mine primarily for 45 acp loading. It seems to run real smooth with those.
But I have shell plates to load just about any thing up to 223.
I use a Hornady Projector for 223, 300 Black out and 357 mag sized cases. It likes those but chokes on 45 acp, .380 ect.
The Piggy back is the press on the right.
