Ejecting case problems No2mkIV

 You should look at both the extractor and the recess in the chamber.
 Secondly, these rifles were designed to operate with the old standard .22 long round, modern cartridges are a fraction longer in the case, you may be trying to crimp the case if you have a short chamber.
 It may be worthwhile to inspect your cases to see where the bind may be.
 Also you will find they have a preference for low velocity rounds, although the odd one handles    hi velocity pretty well.

 

I'd favor the weak spring, crud under the claw, in the spring recess or in the cut in the breech to start trouble shooting. The extractor claw is supposed to "snap over" the case rim when chambering, so anything limiting its ability to do so would be suspect I suspect!

I purchased an SMLE extractor claw and spring, because I expected the problem to be the claw or spring. The No2 claw and SMLE ones are the same length, only need to reduce the thickness of the claw end and radius the front edge for the narrower cartridge. See photos taken before and during the modification. SMLE on the right.

modified one is at the top. However this did not fix the problem. I had noticed the empty case was tight in the chamber and had suspected it was because it was a fired case, so I tried the same case in my new CZ.22 and it went straight in. I blued the case and found that the entrance of the chamber was scoring the case and causing excessive resistance; (the case is centered on a cleaning rod in the photo)

 A gentle lapping of the chamber entrance and a now all is well. Extracted my 15 test rounds without a glitch. 

I believe the  cause of the tightening of the throat is because the original claw appears modified so only the tip rubs in the channel on the barrel, causing excessive load on the chamber edge as you close the bolt; plus they had added a spring stronger than the new SMLE spring which compounds the problem.