[jerry]

Loading blocks are fairly easy. Get a chunk if wood and drill evenly spaced holes the diameter you need.

 

[jerry]

For the .50? Used beer 6 pack containers? Just kidding, I'll look around.

 

[jerry]

Mabe this for the .50? I'm not sure of overall lenght of the cartridge?

Ammo Box - 20 ga. Shotgun 25 Round
This box fits 3" 20 ga. shotgun shells.
Hinged Top Box
Capacity 25 rounds
Please state color choice when ordering.
Price: $2.00 Stock #: 6BE-SH20
Color: Blue Smoke Clear Orange
Qty:

http://www.bigboyguntoys.com/cgi-bin/ez-catalog/cat_display.cgi?6X375438

AH!

5 Ammunition box- Custom for A-MAX bullets 1 Holds 50 For ball and Hornady bullet length rounds $22.00
6 Loading block-28 holes 1 Wooden- Excellent $5.00
7 Loading block-64 holes 1 Wooden- Excellent $10.00
8 Loading block-plastic- MTM 1 Holds 50-fits a little tight $3.00

http://www.arizonaammunition.com/50_bmg_prices.htm