22 conversion kits

[sheepherder]

Originally Posted by ithacaartist

I've noticed the same thing you've noted, and will consider swiping the front of the extractor across the grinding wheel a couple of times so it doesn't jump up like that when the breech block is fully in battery. I'm not sure it influences the flying out deal, though.

The Erma extractor we're discussing is mounted most precariously. What retains it is the tension from the spring and plunger behind, pressing it into the front top edge of the vertical hole into which the extractor's "tail" drops. The swelling below where the plunger's tip rests would, combined with the forward tension from the spring, tend to keep it in place. The guy that produced a round of home made CNC replacements said he deepened the little dimple there. When the extractor rocks up while hopping over the round's rim, it seems to me that this method of retention of the part gets a little dicey. A deeper dimple might actually help.

I've given this a bit of thought, and think what happens is like you say: When the beveled front of the extractor hits the slanted cut in the barrel insert, it is levered up and back at the same time. As you point out, only the tail of the plunger keeps it in the breech cut. The back of the breech cut is a drilled hole, and the cut is a few thousandths less than the diameter of the hole. The extractor has that button on the back/bottom that should be greater dia than the cut, but isn't quite.

I think that John was right about that first shot being too powerful [Remington Viper 22, no FPS or pressure rating on the box] that when the extractor rebounded and hit the insert slant, it jarred the extractor button up far enough to disengage from the bottom of the drilled hole [the dimple], and it sailed forward...

The basic design seems OK; it's just sloppy German workmanship!