Recently I found a seller on eBay selling oversized ER32 collets, and it has been a serious game changer. Most of you know that vulcanite rod stock comes in a slew of sizes, but you can only hold anything up to 3/4" in standard ER32 collets. The oversized collets come in sizes up to 1-1/32" (26mm), and should cover the vast majority of rod stock you'll be using.
If you have a Beall collet chuck, definitely give these a look.
Link to Beall chuck:
http://www.bealltool.com/products/turni ... tchuck.php
Link to eBay seller (no affiliation):
https://www.ebay.com/sch/blacoun/m.html ... 7675.l2562
Pic for attention: