I'm not sure if the Rockchucker press is big enough. I've read stories from web pages that someone has used the Rockchucker but I've also heard the threading was different? Not sure never tried it but I do have a Rockchucker.
I bought the RCBS AmmoMaster Reloading kit for the .50 BMG.
It has everything you need to get started and is a BIG sturdy press specifically designed for the 50.
There are a few places that carry the RCBS and Hornady press so as long as you get the price you're comfortable with you did good.
I bought mine from Natchez Shooter Supplies back in February when they were offering 50 BMG shooters a special price if you hung out at the biggerhammer board.
Price was $325.00 for the kit.
Kit includes: Press, F.L sizing die, Seating die, trim die, and primer seater, I think it even comes with some lube.
Either way it's a good entry-level kit that loads accurate ammunition.
I purchased a Hornady Neck Sizing die to get better accuracy.
My best groups to date are 3 consecutive 5 shot groups at 550 yards measuring. 5 1/2", 5 1/8" and 4 7/8".
It's a fun hobby / sport and the people that shoot the 50's are more than willing to share information and help out.
We have a monthly shoot / match where I live and usually 7 to 9 shooters show up each month. You get to see different 50's and shoot everybody else’s rifle. Always a good time.
TS