Hi Y'all
A bit of late info.
I bought nipples for my ROA which use shotgun primers. I found that because the primers are not supported by the Ruger frame face
which they are in a shotgun. the primer easily fell out under the detonation pressure.The primer then found its way into the Ruger works and jammed. it took a stripdown at the firing point to clear -- I went back to perc. caps they are a lot less bother.
Gordon