I am obviously in the minority here, but I experienced the same thing you have with Lil'Gun in the 22 Hornet, only worse. I had blown primers, stretched cases, sticky cases, velocity swings of 300+ fps, using starting loads with 40 V-Max. But not all would do that, some shot fine. I was afraid to increase powder charge for fear of really doing some damage. Maybe I should have just stuffed it full and forgot it, but I really try to work a charge up, for fear of doing damage to my gun or myself. I tried different primers too, with no improvement. I never did figure out what was causing it, so I just gave up on Lil'Gun. It did this in my Handi 22 Hornet and my Savage Model 40. I know that lots others here have not experienced this and I do not know why I did. I switched to W296 using very light bullets and SP primers and the wild pressure swings went away. I still do not know why Lil'Gun did that.
Here is a group shot with W296 in my 22K Hornet Handi - just a little over 1/2"
Here is a group shot with Lil"Gun in the same gun (22K) just about 3/4"
After my experience with the 22 Hornet, I was a little leery to use Lil'Gun in this gun, so I quit load development with it and stuck to the W296.