RCBS neck expander die vs Lyman M Die

BJung

New member
Has anyone used both the RCBS neck expander die and the Lyman M Die? I want to know which is better.

The RCBS plugs act like a mandrel and expands the neck to .001" in some cases and puts a slight flare at the the mouth.

The Lyman M Die acts like a double mandrel and expands the case neck to a certain diameter and then then expands a segment of the mouth further so the bullet will seat in it and direct the bullet straight into the case. My concern is that a cast bullet can be swaged more than desired compared to the RCBS expander plugs.

Has anyone used both and compared the groups?
 
Not a dimes worth of difference between them since the patent on Lyman's Type M die expired. I also have custom expanders made for my RCBS dies that produce excellent results.

Don
 
I don't have a RCBS expander body but purchased the rod and plugs first. I think the rod threads through any die body. But, what about the mouth? From photos, It looks larger than most resizing dies. At worst, I was thinking of extending the rod outside of the mouth. Is that possible?
 
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