RIO primers

[gunauthor]

I have used Cheddite primers because my LGS carried them at a friendly price. With the current shortage I bought 5000 RIO primers. How does RIO compare with other primers? I shoot practice trap two nights a week (75 targets per session) and shoot moderate loads. Also starting to cast slugs. Any info would be appreciated.

[Hamish]

Any hull that you use Rio primers in will have an oversized pocket that American primers will fall out of. First learned of this trying to reprime Rio hulls with Winchester 209’s.

They are good primers, just oversized.

[megasupermagnum]

Ballistic Products is about the only source of data for them. Other than that, they go bang if you can fit them in the shells. They only truly fit Rio hulls, but you can stuff them into Fiocchi's no issue. You can get them into American hulls, but they fit tight.

[kaiser]

RIO hulls can be used with U.S. primers if you use a reconditioning tool by Ballistic Products to resize the primer pockets the first time after firing. However tedious, it is a simple tool to use and works well to covert the hull to standard 209's. Otherwise, using RIO primers in RIO hulls is the "right" fit.

[rancher1913]

rio's are metric and are smaller than 209's, they will be loose in american made hulls but do work if you can keep them in place. I have a bunch of rio hulls so I use the rio primers in them.

[megasupermagnum]

rio's are metric and are smaller than 209's, they will be loose in american made hulls but do work if you can keep them in place. I have a bunch of rio hulls so I use the rio primers in them.

You are backwards. American primers are about .241", Fiocchi and Cheddite (and presumably other European primers if they exist) are about .243", and Rio is all alone at about .245". All of them are modern "209" primers.

[rancher1913]

well than I got a bunch of wierd brass cause when I use rio's in my winchester brass they will sometimes fall out when handled to much.

you know what on second thought it was the other way around, I was using 209's in rio hulls. getting old sucks sometimes, but I remembered having a problem with primers being loose. its been a long time ago and I have just always used rio's in rio huls ever since.