a3 front sight post

[browningautorifle]

the rear sight location skewed left of center

I'm looking at the rear sight in this pic and see a stake mark/zeroing line on the right side. That must be for alignment of the rear sight at assembly so it doesn't end up too far left? Unless you cranked it over for the pic, it's at zero.

[ssgross]

yes. after disassembly and cleaning, I put the rear sight at mechanical center and went to the range and zeroed the rifle. The windage was all the way over to the left when done. I went home and measured the distance the windage had been moved to zero, and drifted the base over that much in order to have the rifle zero with the windage centered. Not surprisingly when I was done, the rear sight then matched up with the original witness marks that you see in that pic. I assumed those witness marks were struck when the rifle was first zeroed. At the factory? It's canted enough to be an annoyance with the 1.whatever inch front sight, and worth trying to fix.

[browningautorifle]

I had an M1 rifle like that years back. Turned out the barrel was bent in the thickest part and had been since the factory. It was a Danish return and near new because no one could figure out why it wouldn't zero and shoot at different ranges. I straightened it and then changed it for a 7.62 barrel. I wonder if this one was the same, it wouldn't zero and so it was shuffled aside. I just can't imagine a factory not catching this or allowing it passed quality control.

[ssgross]

I wonder if this one was the same

I wondered myself if the barrel could have been twisted. I stopped worrying after I shot it and got solid consistent groups.

---------- Post added at 04:30 PM ---------- Previous post was at 04:27 PM ----------

allowing it passed quality control.

I wonder what the tolerance was. Any variation in timing would be compensated for at the rear sight when zeroing. How much is too much? Perhaps war-time standard was that if the rear sight base could be secured, it was good enough. The cant is mostly noticeable because of how far over the rear sight must be to zero.

[browningautorifle]

I wonder what the tolerance was.

How much is too much

Good questions...

---------- Post added at 01:34 PM ---------- Previous post was at 01:32 PM ----------

I wonder if this one was the same

Meaning I wondered if this one was noticed but never sorted out. They had others and just shuffled it to the back rack.

[ssgross]

I couldn't resist
https://www.askdifference.com/rosin-vs-resin/
I'm not going back and checking if we got it right/wrong either, tomato tomato.

[ssgross]

It's off!!!.
Well, lead shim with aluminum bushing does not work. The lead held the barrel tight, but slipped on the aluminum even with rosin. Vise was clamped on the straight part of the barrel with as much pressure as a 3ft cheater pipe could create.
PlanB worked. The No. 5 bushing (steel) that came with my vise is 1 inch ID. It sits up maybe 3 inches from the receiver. The taper there is less than 0.1. So, I used the lead sheet for the whole length of the bushing, with my bowling ball rosin in between barrel, lead, and bushing. I tightened down with my cheater bar and gave a good sharp yank. Nothing budged. On the second, sharper/harder yank it moved, with a loud squeak sound as it came loose. As I unscrewed it, I could feel a bit of grit from either the park that got in there, or from surface rust.
The wheeler action wrench worked fine. It came with sharp edges all around the upper part that that I smoothed over with a file. I used several wraps of aluminum tape to protect the receiver, but I'll use some of the lead sheet next time, as the aluminum tape left a sticky mess after it was compressed.
Browning, the bowling ball resin looked just like picture of the loose bag on midway's site, and it seemed to work just fine. Maybe this is why brownells gave up stocking it.

[ssgross]

I got worried cleaning up the couple the few small marks from where the lead shim squeezed under pressure. It was almost like a glaze on finish. Tried brass brush with oil, no go. Put a fine brass wheel on my dremmel on low speed, painted the surface with kroil. Nylon brush then took off the shiny brass, along with whatever lead marks there were. Threads look good. Phone needs to charge while I clean the sticky off the receiver. Then I'll take pics before reinstalling.
Should I put anything on the threads when re-assembling? I read elsewhere that some people use nickel anti-sieze when rebarreling.
Chuck's how-to thread says no lube, oil creates hydrostatic pressure when tightening, making it hard to get aligned. So I was thinking of assembling dry, then a good soak in some kroil to get down in there, similar to the oil soak it got after the barreled action was parkerized.

[browningautorifle]

We used to use a steel outer shell and poured lead jaws custom to what we were unscrewing. The barrel was grabbed in lead also with rosin and tightened down with a two ton jack in a steel box. The wrench was two bolts with a handle and a set of square outer jaws. I just eliminated the middle man and used straight aluminum so it could deform if need be and was cheaper to make. Usually there's been something to grab, a shape. The long handles help to avoid jerking the receiver. I'd reassemble the way Chuck suggests...dry will be good.

[ssgross]

I'd reassemble the way Chuck suggests...dry will be good.

That's what I done. The final alignment took a little less undoing than I had calculated, I assume because I was generous in my measurement of how far left the rear sight was at zero.
What is more important is the bolt closed, so no extractor groove problems. I then too the extractor off, slid in a no-go gauge, and whatdayaknow, it no go! Threads all looked good inside and out, no peening at the shoulder. Taps on the wrench handle with heavy rubber mallet and it slid right in to position.
Attachment 114383front sight all lined up. Used a hex wrench underneath to make sure I got a good flat reading.
Attachment 114385This was where it was at hand tight.
Attachment 114386Attachment 114387 Final alignment.
Attachment 114388Final headspace on the no-go gauge.
Time to put it back together and go shooting!

EDIT: Not so fast silly goose...you have to slip on the handgaurd ring, rear band, front band, bayonet band BEFORE you put the front sight back on!