Yuku free message boards

I loaded some 110 grain surplus M1 carbine bullets. These are round nose bullets with an open rear showing the lead. That is in front of IMR SR 4759. I like that if fills the case over half so you are not in danger of powder positional detonation. I loaded ten rounds with 20 grains of powder in Privi cases with CCI primers. The chronograph was about three foot beyond the muzzle. It surprised me that it was clocking 2200fps - I expected lower. I was however pleased it was very accurate at 100 yards shooting about an inch and a half spread two inches lower than Swiss surplus. I also loaded 20.5, 21, 21.5, 22, and 22.5 grain powder charges in individual cartridges. My notes are in the truck but there was a steady progression of velocity to about 2600fps - but the last load of 22.5 jumped to 3264fps. That exact number stuck in my head since it surprised me. I wouldn't try 23gr as the increase was not proportional and I'd worry about what sort of pressure it was generating. Even that load however had no signs of over pressure. The neck and case were not distorted or stretched in any way and the primer pocket is tight and the firing pin imprint flat and not ridged around the indent. As the charge and velocity increased the point of impact walked off to the right and down however. The recoil was very mild - more than a .22 but a softer shove than .223 in an evil black rifle. The muzzle report is much quieter than normal. The powder is a bit dirty and it doesn't blow the brass out to a good seal on the neck (except that last large charge) - there is a sotty ring around the outside of the case necks. These necks are a consistant .0115/side. Less than GP-11.
I'm going to try this again but start at a lower charge of 18 grains and go in smaller increments of .2gr back up to 20gr. I was hoping for something slower to be able to take small game with little damage. I like the point of impact being on the same vertical line as stock ammo. We'll see if it stays there with less powder. I'd like about 1600fps. If that doesn't work out I'll try a little heavier bullet in front of the same charge. Something around 140 - 150gr.
I also had better seat the bullet a little deeper. I had one round of the 20gr that felt different closing the bolt. I extracted it instead of firing it and it left the bullet stuck in the throat. A hardly-felt tap with the cleaning rod made it fall out. It had tiny bright spots around it where it had just kissed the rifling. I'll back it off .010" or .015" and if it gives me any more problems I may crimp it lightly.