no latch engagement what next?

[JeffDavis]

I have been attempting to fit a barrel to a frame I acquired. I have gone through the FAQs to get advice and have done the following to eliminate barrel/ receiver gap.
Filed the chamber face flat to eliminate below flush case
Deepened the pivot hinge
very light smoothing of the latch shelf.
The barrel gap has been eliminated and settles into the receiver just like my factory fitted barrels. The problem is, there is NO latch engagement to keep the barrel from opening. I have tried a shim on the pivot, but could not close the barrel as I did before I added the shim.  My shim is aluminum foil doubled over, and I have tried a single unfolded piece with no results.
I am hesitant to file any further, but cannot think of what else that could be done.  I think there is an issue with the barrel catch not engaging forward enough as the barrel release seems to be much looser than my other frames.
Any and all ideas are welcome
 
Thanks
Jeff

[thejanitor]

I am no gunsmith and I don't play one on TV, but if you filed the breech face, and shimmed it, everything moved back toward the reciever as planned, the shelf is probably in the way of the latch, smoke the shelf and hold it all in place and then look to see if the very point of the shelf is rubbed off (the soot) from the non engaging latch... I bet you are close but not quite far enough. BUT EVERY STROKE OF THE STONE OR FILE IS HUGE, GO SLOW.
Here again without seeing it this is my guess by what you described.  Good luck and GO SLOW.. thejanitor
 

[gcrank1]

You are probably so close.........
On one fit up I did that required facing the breech and deepening the pivot did just as you seem to describe; it wouldnt hardly catch and I had to, ever so slowly, fine tune the pivot to get the breech to 'settle in' just a tad deeper. I was fitting a .22LR swap barrel into the .22 Mag so I had the original barrel to switch in to see how the .22LR barrel was still up a little too high in relationship to the standing breach. This kept the latch from engaging the shelf.
I have to wonder why you tried a shim on the pivot when the 'headspace' was already tight? Well, anyway, you saw that made it worse, right?, so that isnt the way to go.
When you get a little engagement happening it will probably start to make more sense. I like to fit fairly tight so the parts can work in under stout closings and actual firing pressures. Quite often all that is needed then is a tiny bit of final tuning, if at all. If you fit it up too loose it wont ever get tighter, kinda like the woodworkers joke,'cut it off twice and its still too short'.
BTW, are you doing this fitting with the extractor/ejector out? You dont need it giving you any false signals. No need for it there until the barrel fits right anyway.
I am way leery of changing the latch shelf other than maybe a couple of light strokes from a fine stone. It is easy to think of that spot as the solution, but, IMHO, it is not.

[bikerbeans]

+1 on TheJanitor and make sure to keep the latch shelf angle the same. 
 
BB

[JeffDavis]

I did take out the ejector before I began filing the breech face. I only tried the shim to rule out too loose a fit. I will take a break from this barrel and try the latch shelf again in the morning.
Keep the ideas coming guys, nothing wrong with too much information.
Thanks
Jeff

[cwlongshot]

Your on the right track...
 
Does your receiver have the little cap over the hole allowing you to see latch engagement?
 
If so, POP it out and have a look see...
I agree, you need to remove material form the shelf likely in near the amount you removed form the breech or pivot. Be sure to GO SLOW and maintain the angles.
 
CW

[cwlongshot]

Any progress?

[JeffDavis]

Well, I have taken down the receiver and removed all the trigger group, the hammer, and the barrel catch. The barrel catch seems to overhang the latch shelf when I match up the two together. Does this mean I need to file down the shelf until the two meet evenly, or do I file deeper until the catch is below the level of the shelf edge?
Better yet, do I quit while I can still get the barrel into my other receivers? There is not a single barrel in the stable that will latch together with this receiver. I am no expert, but I can't see any other issue than the barrel catch.
I am still trying to get the receiver back together, so maybe I will get lucky.  Not quitting yet!

[gcrank1]

I am still not convinced that it is in the latch and shelf, but rather in the barrel not seating down quite completely into the receiver. I can be wrong.......could the very top of the barrel, on contact with the standing breech, be prventing it from dropping that little bit more to latch engagement?
The best approach is to only remove metal from the cheapest and most easily replaced part(s). To me that does not generally include the shelf but for only very light and minimal stoning.

[cwlongshot]

How does the barrel look at the top where it meets the frame? (Just behind the scope mount.)
 
CW

[JeffDavis]

It is showing a bit of gap at the top of the barrel. Light can be seen at the upper third of the barrel, but does not appear to show below that.

[bikerbeans]

if you have a gap at the top of the barrel/frame then you have to remove material from the underlug pivot.  This gap at the top indicates the barrel is not rotating all the way down into place.
 
BB

[cwlongshot]

If you have a gap at the top of the barrel/frame. This gap at the top indicates the barrel is not rotating all the way down into place.
 
BB

And if its not all the way down, it cannot be allow to latch..