I use the tool all the time. Like it a lot for hunting. Can make some real deadly ammo. Great on ****. I have found that it works best in guns that were designed to shoot short, long, and long rifle. You can modify the bullet as much as necessary and still works. On other semi auto's (or bolts for that matter) that were made to shoot LR only, you have to experiment a little for the amount of modification the gun will allow before it starts to jam. I have a Marlin Model 60 and a Remington 597 that if you take it easy on the modification it will work. What I do is when I find a modification amount that works well in a gun I will use a marker on the rod as a guide. This also gives consistency for the ammo and improves the accuracy. You can get real good results with pratice. I like to use my 39A the best for this ammo though. Does not jam, and can make some ammo that will put something down real nice and fast.