I hope someone has a fix for this. I am trying to replace the original hammer with a new lighten one from MVA. Side by side they seemed the same but I guess not exact.
Now when I open the action all the way the block and hammer move down too much causing the hammer spur to get stuck inside the action. I think it might have something to do with the extractor. 

Since you are after lock time and the part isn't original, my quick and easy solution, is to cut the hammer spur off!

A HW/LW, doesn't need a hammer spur, especially a target rifle. Even in the field it's safer and faster, to carry it with the breech block, part way down, rather than carrying it on half cock.

Another modification to decrease lock time, especially for a flat spring, is to use the half cock notch to fire from. It's fairly easy to increase spring pressure on a flat spring action, if you need more, when using a reconfigured half cock notch to fire the rifle.

Frank

No John there are no marks. It has to do with where and when the block comes in contact with pivot point of the extractor it's the extractor that stops the block/hammer assembly's downward travel. I already know what I need to do. Just throwing it out there to confirm it. So far that hasn't happened. No Frank, I am not cutting off my hammer spur. Marlinguy, yes I did line them up as you said there is slight differences. 
I did have to stone the full cock notch to keep the hammer from falling when the action was closed. The half cock notch also dosen't engage and still needs stoning.Good eyes! 

Gunsmiths I welcome your thoughts.

If it worked correctly beforehand, and you then changed only one part, and you now have a problem, your problem lies only with the one part you've changed.
Don't fix what ain't broke.

The firing pin is holding the hammer back allowing it to hang on the frame.  I can't see how changing the hammer would cause the problem unless the hammer spur is slightly different. Quickest fix would be to take a small amount off the end of the hammer spur so it does not hang up.

I recall having the same problem in a HW that I rebarreled.  I didn’t have the base for the main spring and was improvising.  The thicker barrel needed a thinner base, and then the end of the hammer dropped into the action, went too far back, and snagged.

What I did was to file the top of the base I made.  IIRC (it was a while ago) this made the mainspring dip downward at a slight angle.  Not enough to seriously add compression to the spring, just enough so that bumpy little tab on the end (designed by a genius!) pushed a little harder on the end of the hammer’s cocking extension (that comma-shaped thing in front).

Suddenly, otherwise inexplicably, the hammer spur still dropped into its slot in the frame, but didn’t go back and snag on it coming back up.  I declared victory, for whatever reason, and went on to other things.

You might try pinching a piece of shim stock between the mainspring and the front and then the rear of your mainspring base, and see if “tilting” the spring slightly helps your problem.  It isn’t a permanent change to any part, so even if it doesn’t help, you’re no worse off.

(By the way, you wouldn’t want to unburden yourself of that ponderous, heavy, jarring, ruinous-to-accuracy old hammer, would you?) 

I don't know weather or not mva claims this is a drop in piece or not but I do know they are very willing to talk to their customers about real or perceived problems.

I bought an MVA Hammer to put in my low wall and it does the same thing. I thought it was because no barrel has been installed yet and the hammer didn't have tension from the lever spring.  Now, I'm not sure.  However I saw that the original Winchester  hammer has two radii on the back of it where the MVA hammer seems to have just one constant radius.   Does anybody know why the original Winchester hammer has two radii?