I installed a mark2 volquartsen accurizing kit, TK slingshot and I ordered a TK hammer bushing. However the TK bushing will not fit inside the VQ hammer. It fits in the original, but not the VQ. So I used the bushing that came with the mk2 VQ kit in stead, and left out the piece and spring that is the mag disconect.

The problem is once I get the mainspring housing back in, the bolt wont come all the way back.

I've tried about 50 times, making sure the hammer bar is resting oN the sear, watched 10 youtube vids, but I cant get it.

Is this related to using the mk2 hammer bushing?

I will be that your hammer strut is not sitting on the mainspring just right.

1 Make sure your pistol is not loaded
2. Take your mainspring out of the back of your grip frame and remove it from your pistol.
3. pull and hold the trigger to the rear.
4. use a pencil or cleaning rod to fish up through the back of the frame where the mainspring goes and push the hammer forward to the "fired position" then let off the trigger.
5. hold the pistol so that the barrel is pointed down at a 90* angle and slide the pin portion of the mainspring up through the frame and upper while leaving the mainspring housing and locking lever sticking straight back out of the pistol.
6. rotate the barrel up vertical to a 90* angle and then rotate the mainspring housing into the grip frame making sure that the hammer strut centers itself in the mainspring housing and lock the lever.

If you followed all those steps you should get your pistol to pass a function check and be in business.

Thanks, I did have the hammer strut wrong.

I have run into another problem though. The VQ trigger is very gritty. It's the plunger scraping. It gets hung and is just very abrasive.

I put all the factory parts back in, less mag disconnect. I will be returning the VQ trigger kit because of the trigger plunger as well as the TK hammer bushing not fitting.
I will probably order another kit, or a trigger, sear, and hammer seperately, because if it works, I can tell it would be very nice. It was pulling around 2lbs 3oz. Compared to 5lbs 8oz stock.

Anyone heard of these problems with the VQ stuff before?

Never had a problem with Volquartsen parts in my Ruger Mark III Hunter.  I have a Trigger Accurizing Kit and few more internal items from VQ.  Trigger is sweet and after 10K rounds it is even better.  The mag disconnect I have is from TK.  Good bunch of people there.

I just stuffed a MkIII 22/45 TK stainless hammer bushing, bought from Amazon, Into a Volqaurtson MkII 22/45 accurizing kit trigger with no problems. Smooth.