I got Rocky Mtn turned 12ga cases, and am
developing loads. They are 2 7/8 inches
long are for use in NEF and shortened
in 1887. These cases have shotgun
primers. Now these cases with shotgun primers and the two cases of ours we put small primers in don't fire the slow rifle powder loads
reliably,like cases with bmg primers.
Our testing is with 600 hardened Dixie slugs.
So I have and am testing slow shotgun powder and fast rifle.I tested 5 shotgun powders and
the primers fires then ok but the quick peak pressure when loads increased to get velocity
wanted in NEF caused too much case expansion just ahead of the base.Cases ejected ok but
that expansion and resizing will ruin cases
in a couple shots.These cases have a real thick base, and are machined to glass smooth finish.Nice cases.
I now testing AA1680 Ball and it looks good.
Have got loads up to 105 gr with 2 wads in
the Rocky Mtn case, and only .002 expansion
of case ahead of base. Will chrono next and
expect it to get velocity we want in NEF.
Nice thing about this testing is that same loads will work in shortened 87 case by just
using less wad column.Ed