Why do I feel my mainspring housing moving under dryfire?

[MAC702]

So I did a complete teardown and rebuild of my Springfield Armory Range Officer 9mm.  This time I moved the Dawson housing/magwell to the Kimber .45 (steel frame) that I'm using for SS, and I put in a different steel housing that has a much smaller carry-style magwell.  I put the sear spring back in carefully, and everything works.  BUT, under dryfire I feel the mainspring housing moving slightly, like a little snap from the sear spring moving underneath it.  It appears to be pivoting on its pin, and moving very slightly inside its rails that it slides up into; just enough for it to transmit the snap feel to my hand.  Is this an issue?  I don't remember it doing this when it was on my other Kimber (aluminum frame) .45.  I doubt I'd feel it under recoil, but it sure is a weird feeling when dryfiring.

[Loves2Shoot]

Because there is a spring in there that pushes on your hammer strut and it moves when the sear releases the hammer.

[MAC702]

Well, yes, sir, but I'm feeling it very pronounced in this instance.  I've been shooting 1911s for 40 years, and this is markedly a different feeling, as previously there was none perceptible.  Been playing with it a bit now, and I can wiggle the mainspring housing with my fingers.  Again, hardly moving it much at all, but my other installations and guns it doesn't move at all, but it only takes a tiny bit to transmit the "slap" against my palm.  Is it nothing to be concerned about, and the movement is within specs, and I won't feel it under recoil anyway?  It's actually a little distracting when dry-firing now.

[Ultimo-Hombre]

 

Perhaps it's simply a looser fit. 

 

Edited April 9, 2017 by Ultimo-Hombre

[zzt]

If it fit correctly there would be no movement.

[Gary1911A1]

I wonder if it has anything to do with that stupid mainspring locking device Springfield uses?

[Steve RA]

Take it out and lay it on it's side and hit the little rib with a hammer, then do the other side same way.  Expanding the rib slightly on both sides will remove some of the play between it and the frame.

[MAC702]

Good thought about the lock, Gary, but that has been eliminated with this different mainspring housing.  I guess this is just a little bit loose of a housing.  I don't think it can hurt anything, and I'll probably get around to putting another Dawson ICE in it anyway before it drives me too crazy.  I just wanted to make sure.

 

Steve, now there's an idea.  It shouldn't be hard at all to move a little metal around in that slot to take out what little play there is.

Edited April 9, 2017 by MAC702

[NoSteel]

Use a spring loaded punch to place a couple diples in each rail of the mainspring housing then re-fit.  This should move a small amount of metal around . Should tighten right up and is easily tuned with a file later if needed.