The Phoenix Patchett - No 2627

[browningautorifle]

Outstanding use of muffler tube. Albion Motor Works would be proud...

[Peter Laidler]

Brilliant idea..........

[Vincent]

Thanks gentlemen.


Attachment 54184

Drilled the firing pin channel using drill stops to .075" short of where I think the firing pin protrusion should be. I will make the final cut with an end mill after I cut the channel for the firing pin tang.

Attachment 54185

Looking down the firing pin channel from the back.... there's light at the end of the tunnel.

[Vincent]

Attachment 54194

Machining of the breech block is done except for setting the firing pin protrusion. My straight-end end-mill isn't long enough and I am thinking it might be better to make the firing pin and tang first. That way I can "sneak up on" the firing pin protrusion length.

[Vincent]

Started on the casing and have some choices to make. Any input would be, as always, greatly appreciated.

Attachment 54214

Top is a section of 4130 DOM. They were out of muffler tube, so we'll have to make do. I rolled the end, pinned and welded the barrel support in using a bulged Sterling barrel shimmed at the breech end to hold the support while I welded. It seems to have come out fairly well. Best I can tell, there's an even space around the breech end of the barrel.

A friend found the saw cut Mk4 front shroud. It looks like it might be just long enough to butt weld to the section of Patchett receiver.

I would like to keep as much of the Patchett receiver section as possible and preserve the machined welds around the magazine well and pistol grip frame. They would be very hard to duplicate and there's a very strong chance of warping the tube when putting that much weld down.... even with a "cold weld" there would be shrinkage on the long runs at the top and bottom of the magazine well and the grip frame especially.

I am leaning toward using the Mk4 front section. I will trim the Patchett section, put them in a jig and see if there's enough to work with.

[Vincent]

Attachment 54336Attachment 54337

Cleaned some most of the slag off the Patchett section and it looks like there is enough to weld it to the Mk4 shroud. Used the Mk6 jig to get a rough idea how the sections will fit.

[Vincent]

Attachment 54374

A little more work on the fixture and it will be ready to weld.

[Vincent]

Attachment 54398Attachment 54397

The denial bar trimmed to fit inside the tube better.
(It prevents someone from easily putting a full-auto bolt in the gun.)

I have to run a reamer inside the tube after welding the sections together. It's the same process Sterling used when the guns were built and described in Peter's book.

If you look closely at the cut sections of the receiver tube, you can see the original reamer marks. They go from the back to forward of where the barrel breech end sits. It's this process that ensures concentricity inside the receiver. I will do it by hand in two stages using an adjustable reamer. The first run will be set at the inside diameter of the crimp. The second run will be at the receiver id and stop short of the crimp area.

Once that is done and the bolt moves freely, some double-sided tape will hold the denial bar in the slot cut in the bolt. With the ejector installed to align the bolt, the denial bar gets plug-welded to the receiver. Two small light welds first. Then the bolt is removed before making two penetrating welds. Don't want to weld the bolt inside the gun. Then the light welds are milled out and replaced with strong penetrating welds.

The denial pad for the trigger pack just gets welded to the outside of the tube.

[Vincent]

Attachment 54403

Had to cut this spot weld out.

Attachment 54404

It went better the second time.

Attachment 54405

The welds look ugly. That is because a nice looking long run would warp the thin tube. So I do several short welds and "hopscotch" around the tube letting each weld cool before adding one next to it.

Attachment 54406

It came out nice and straight.

[Vincent]

Attachment 54408Attachment 54407

After reaming by hand for a couple of hours the moves freely in the tube.