ronlaughlin
Not necessarily.... most bullets do not sit on the bottom of MMP sabots, they are built that way. However when you push the bullet down the bore the stretching and compressing the petals will allow the bullet to seat on the bottom of the sabot. This is done to insure that the sabot, which is a whole lot lighter than the bullet, is
locked tightly to the bullet and any spin imparted on the sabot is imparted on the projectile (especially in warm bores). It is the old physics rule... a body at rest tends to stay at rest....
Again in the old days... sabots would spin on the bullet and the projectile never reached the correct RPM.
To test this Ron, remove you breech plug and push the combination all the way through the bore, when it comes out of the breech it will be seated in the bottom of the petal.