RE: what' s the difference except price
If your buying on Ebay and want a deal you have to be patient , I got a rockchucker that was like new for just under $60 with shipping . It took about two months but I wasn' t in a hurry . The JR will also do a good job its just not as heavy built as the rockchucker. I used one for years and never had any problems with the ammo it will load .