I installed the feed throat upgrade kit in my Glenfield 60. I was experiencing a lot of jams - instead of cycling into the chamber, rounds would jam up in the feed throat. Tried replacing the spring in the tube magazine, that did nothing. So I tried the feed throat upgrade kit - new throat, lifter, and spring. I drilled a hole in my side rail to accomodate the 4th pin in the new style bolt; as near as I can tell I positioned the hole properly. After re-assembling everything I could not pull back on the charging lever. Something was binding it. I had read accounts that the new lifter lever does not work with all older bolts and may need to be filed down. Did so slowly, a little material at a time, until I could get the action to cycle. I took the gun to the range yesterday to see if things worked. At first loaded two rounds. They worked. Then I loaded ten rounds. All ten went through without a hitch. It turns out that this was just a tease. The next loading produced one failure to feed. Ok, no big deal. Additional loads created more frequent failures. It got to the point that I was getting more failures than successes. Tried three different makes of ammo, too. What would happen is a round would fire, the action would cycle and the next round would make it to the ramp on the feed throat but not get pushed into the chamber. Had a few times when it tried to feed two rounds at once. At one point, the range called a cease fire (mandatory to unload your gun at this point.) Working the charging lever to empty the magazine also produced the same problems. With the old parts, I would get a jam that deformed the round and stuck it in so tight I had to dig it out with a needle nose pliers. With the new parts, the round that caused the jam would simply fall out of the action. Not much of an improvement! So, any thoughts on what I've done wrong here?