I purchased a Pack Lite upper for my Mk II and tried to put it on the 22/45.  It doesn't stay on when put on.  It just falls off.  I tried it on my metal frame regular Mk II and it stays put just fine.  Snaps into position and holds there.

Is there a difference between uppers for Mk II and MK II 22/45?  I assumed they were the same, but I could be wrong.  I wanted the Pack Lite on the 22/45 as it is a much lighter grip.

I may run it back by the shop and see what they say.


Any info appreciated.

Doc

I bought one for my MKIII 22/45, it does the same thing. Once you put the mainspring housing in, everything stays tight. It was tough to get the mainspring in at first, tight fit. But it functions fine.

I had the same issues with mine as trukreltrog's 22/45.  I really didn't think is was that big of a deal.  When the mainspring assembly was finally set through the hole in the barrel and bolt, it held together just fine.

I thought it was a problem unique to my pistol, so I never called Tactical Solutions to see if this was a design flaw...