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If I read the blurbs correctly, here's what you'll get in your kit:
- Rock Chucker Supreme Single Stage press
- 505 scale
- Uniflow Powder Measure
- Speer Reloading Manual
- Hand priming tool with small and large primer plugs
- Folding Hex Key Set with 0.050", 1/16", 5/64", 3/32", 7/64", 1/8", 9/64" and 5/32" keys
- Universal Case Loading Block, which holds 40 cases in most rifle and pistol calibers
- Case Lube Kit, which includes a 2 oz bottle of Case Lube-2, a case lube pad, 2 case neck brushes for .22 through .30 calibers and an accessory handle
- Powder Funnel for .22 to .45 caliber, including the Winchester Short Magnum calibers
- Chamfer and deburring tool for .17 through .45 caliber
The Speer manual is pretty good for bringing up to speed the most important piece of reloading equipment: The squishy stuff between your ears. However, the Speer book won't have data for the 450B cartridge. You might consider getting a copy of the Hornady manual. Hornady #8 is really inexpensive and on closeout now because they just published #9. #8 is OK because there's nothing new about the 450B in #9. I like the introductory material about reloading in the Hornady manual a bit better than that in the Speer manual. They complement each other nicely.
(Trust the manuals, and not data you see on the internet. The guys at Speer, Hornady, Hodgdon, etc., have an interest in keeping you alive and healthy, so you can buy more of their stuff. The guys on the internet, not so much.)
I don't see a Caliper on the list of RCBS items. There are several types of RCBS-branded calipers sold. A caliper is way more important than a tumbler. If you read the reloading threads on this site, you'll begin to think that we all run around with a caliper super-glued to our palm. You aren't far wrong. One of the first things you'll find in looking at the manuals are measurements like trim lengths and overall length of loaded cartridges (COL or COAL or OAL). You will need a caliper to perform these measurements.
A set of RCBS check-weights will be of great comfort. They'll let you know whether your balance has gone wacko.
Good luck, and be careful. And come back and tell us what we forgot to include in our advice.
--Bob