Ya don't have the mold but was considering using it with a faster burning powder like RL-15.
Had real success with the copper plated rounds and RL-15, and unless I've got my theory mixed up (new to the casting game) a faster burning powder would cycle the semi more reliably
Looked in the Lyman Book
Looked at 20-25 different rifle (Cal) loads Did not see Alliant RL-15
Alliant site quote Similar burn speed to IMR 4350 with added velocity.
I have read of people using 4350 with cast but it is not near the top of the list.
you do not want velocity with cast the max max max velocity for any round from 223 to 45-70 including stuff smaller and including the belted magnums is app 2500 fps
every thing has to be perfect , barrel twist, alloy, powder, pressure, bullet shape, lube etc.etc unless you are paper patching
with a semi the most important thing to getting the action working correctly is port pressure, when and only when that bullet passes the gas port
too high and you bend/ break things.
too low and you get jams/non extraction/not picking up rounds
if you read my comments about barrel twist and velocity
if your rifle has a 1/10 twist, if you were using a bullet 130g to 210g (if they would fit) the fastest you could push it is 1800-1900 fps
the lower weight bullets never build enough pressure to work the action
Just a note to people thinking about cast, some powders are position sensitive so a 30 cal 150g bullet with powder XYZABC in
30-30 is 15g
308 is 17g
30-06 is 22g
300 win mag 23g
so all the above loads the powder charge just rattles around in the case
to get powder to be not position sensitive a filler must be used and a bit of research needs to be done because some powders do not need a filler
some powders can be dangerous with a filler etc etc.
I have used 5 different powders in the 308 with 3 different bullet weights
and have had different problems.
I have kept velocity down and the worst leading I had came out with one pass of a brass brush
worst target --> could not get a group at 100yds 8x11in target
thought scope was gone (velocity too high)
loose primer pockets after 2 firings (presure up there --> 5" group at 100 5 rounds brass taking a beating with full function
the load I am working on I think is it --- for one bullet weight