Some info about our slower powder reloads in plastic and
brass cases with shotgun primers for modern 12ga guns.
I now prefer the IMR 4759 over 4227 as we have had
some delayed firing problems when the loaded cases get
real cold with 4227..And with slower powder loads use
magnum primers.

A side note,in same vein, you know I now use FED239
mag primers in my 8ga and 4ga, but we find they they really
solve the real cold gun, ignition problems, in muzzle loaders
using black powder substitutes, with shotgun primer
inline guns. We tested 50cal and a primer sold especially
for ML when fired,no powder, only saw a tip of the flame
out the barrel, a FED209 mag about 4" flame, buta Fed 239
Mag primer about a foot of flame.

Some more info from the old days, here is picture of
a variety of slugs being promoted and used a century ago.
And 2nd picture Paradox cases old and new.Bottom one is a
modern version sold by H&H for slug hunters.Ed