Thread: What causes key holing in sub loads

I'm trying to work a load up for my 308 tikka barrel
If I seat them deep enough to feed they key hole, if I seat them out to engage lands they won't feed

I'm using lead cast flat nosed projectiles

What causes projectiles to key hole?
What things help to prevent it?

At what speed do lead projectiles grip and spin with modern rifle twists 1-10 to 1-11 ?