SP101GP100. reassembly problems

I purchased two of the kits, one for my Sp and the other for my relatively new GP100. .44 Sp/5hot/3". I have started with the GP100, After viewing the instructional video a number of times, (as well as reading the Shooting Times article (that led me to the site and ordering the kits) I commenced on the GP. disassembly was pretty straightforward, these are my 5th and 6th Ruger DA revolvers and I’ve worked on all of the.
Deburring and polishing went fine as did the spring changeover. I was able to get the trigger group reassembled without difficulty. Without the hammer installed, working the trigger DA mode rotates and lock up the cylinder properly and solidly, I can see that the transfer bar is functioning properly.
However I am having problems when reinstalling the hammer------and having it function. I can get it in and pull the trigger, and have the cylinder rotate and lock in place. But I can’t get it to move back the last 1/4 inch or so to either drop the hammer in DA, or have the sear engage for a SA release.
ny I have taken the hammer back out a number of times, checked to assure it is assembled properly reassembled it and re tried----with the same non-result. whatever I’m doing wrong at least I’m being consistent about
I can t see into the action to see if the Hammer, sear, and the hammer dog are engaging properly, It feels like somehow the hammer, hammer dog, and sear are wedging it solid. I’m completely baffled. Any good advice would be appreciated. I’m not a novice at this, Ive tuned Colt and S&W DA Revolvers, Ruger Security Sixes and my highly customized Ruger Redhawk.


follow up to the above: After much difficulty and trouble getting the hammer to function I took it to my friendly pistol smith. He had problems too; With the either of the springs in the kit. For some reason they would not allow the the hammer to move back enough to engage the sear or the hammer dog. so we reinserted the original factory trigger return spring and it worked just fine. it might be just a quirk of my pistol, or the 44-SP 5-shot GP100s may require a different spring, than what I got in my kit., but it is working fine and the polishing lubricating and shims make a silky smooth DA pull-----which was what I wanted.

Now on the the early 101 357M.