Meloniting? Watch for excessive pressure.

[butchlambert]

Joe I'm not looking for an apology. So MMI TECH said it was tolerance stretch or? I do know a little about heat treating and case hardening. I'm going to take a barrel over to the tool grinding shop that I use. I will let them check the OD with their Optical Comparator and double check the OD on their surface plate. I will send it to MMI TECH and have them treat it. I will have all the measurements done again. I would suspect that your tolerance stacking was not buffing the surfaces after the treating.

 

[Joe C]

Joe I'm not looking for an apology. So MMI TECH said it was tolerance stretch or? I do know a little about heat treating and case hardening. I'm going to take a barrel over to the tool grinding shop that I use. I will let them check the OD with their Optical Comparator and double check the OD on their surface plate. I will send it to MMI TECH and have them treat it. I will have all the measurements done again. I would suspect that your tolerance stacking was not buffing the surfaces after the treating.

Butch,

I'd be very interested in what you find out sir. I know that it took a LOT of strokes with 600 and 800 grit lapping compound before the guns would function properly again. It was a pain. Getting the sights back in the slide was a whole different ball of wax. I had one fellow smith tell me his did the opposite on the sight cuts and they "grew" too much. Personally, me thinks it's probably fine for rifle barrels, but for smaller parts on pistols, not so much. The heat has a tendency to change things too much on small parts, which is why they won't do extractors, etc. on 1911's and other pistols.

 

[fredhorace77]

Joe, it may be 3 microns thick, but it is not a coating or buildup. The treatment treats 3 microns deep, not on top. Bear in mid my Deltronic pins are only in .0001 increments, but I would think I could feel it if it changed.

I will have all the measurements done again. I would suspect that your tolerance stacking was not buffing the surfaces after the treating.

just curious...if it doesnt build on the surface like you previously stated then why would it need "buffing on the surfaces after treating"

 

[butchlambert]

Fred, The only thing is the residual from the hot bath salts. The treatment is from the surface in and not on top. I've got some machine work to do. I will be back on the forum later.

 

[LongRanger]

I wish a metallurgy lab technician at any of the companies specializing in this treatment process would jump in and give us some answers.

Frank B.