1897 Project No. 1

[ssgross]

rust and most of the pitting gone. All that's left are some deep nicks. There was only one little spot around the dent, no bigger than 1/8" across, that indicated where the dent was. I'll swage one more time after polishing the bore this week with a flex-hone, and triple checking the final size.

[browningautorifle]

I think he clamped it too tight in a metal barrel vise, busted the extension (which had the correct serial on it) and bent the barrel getting it on or off

Sounds like maybe...

[ssgross]

next bit todo is to fit this new receiver extension to the barrel. The magazine opening stops hand tight at 10 o'clock. at 32 threads per inch, that means we have off ~0.018 to go into the shoulder magazine opening at 5 o'clock before torquing down to 6 o'clock. The old broken extension still screws on, hand tight at 5 o'clock, and the receiver locked up tight on it with a few notches of the sleeve to go. So I put it on and did some measuring from the shoulder where the adjustment sleeve sits inside the extension to the chamber face. It's 0.823. With the new extension hand tight, it's 0.625 or so. So I should carefully hand fit with files, removing material from the front of the extension.

This wasn't too hard, but time consuming. I then tightened down the extension, put an adjustment sleeve, and whata-ya-know...a perfect tight fit right! Dummy round chambers and ejects just fine! Just when I'm about to pat myself on the back for my beautiful hand fitting metal-to-metal file work, there is daylight between the receiver and the extension, and a bit more than a sliver. I have 3 other adjustment sleeves to try to close it up. If that don't work, then I'm out a few cases of beers worth for the ruined repr-extension, and I'll sendit off to get done.

[ssgross]

Happy Thanksgiving!
I finally got some shop time on this. I used the existing front bead to align my bayonet adapter, and file in the rear most notch to lock in the alignment.
I then marked and bought cut back the barrel...mostly square, and hand filed until it was pretty dead on.

Now we have a problem. The bore is not concentric with the outside of the barrel. The top of the barrel has an extra whopping 18 thousandths of thickness! very noticeable with the naked eye. Is this normal for these? I'm not so sure I want to continue. The notch for the front screw is about 18 thousandths deep, and it's location is where the barrel wall is thinnest. the thickness where the last screw goes is 51 thous.

[browningautorifle]

The bore is not concentric with the outside of the barrel.

That is absolutely normal for those guns when cut down. Lots of others too...I cut down a 700 Remington heavy barrel in .223 and it surprised the other guy present that the bore was in center... I've seen .22 rifles like that too.

[ssgross]

I suppose I'll continue then. My lower bound of barrel wall thickness at that front screw will be ~0.033 then. Likely a bit more. the repro bayonet adapter isn't as snug up front as it is in the rear.

[browningautorifle]

All of that sounds normal because of barrel taper and the way they formed the barrel stock. It was always a crapshoot when cutting a barrel to riot, would it be thicker on one side?

[ssgross]

well it's looking good. After fitting the first screw on the bayonet adapter, I realized I needed some sacrificial ones - they are #10 x32. Fitting them snug against the harder barrel steel wears the threads. If anyone reads this, get a box of stainless screws as you will get more trials out of them, and save the original screws for the final assembly.

Time to blue everything else, and I haven't worked on any of the wood yet. Need to make a final pass at squaring the crown up too.

[browningautorifle]

I'll bet if you'd used a couple hose clamps to hog it tight and then run in taps you'd have had better result with the screws.

[ssgross]

run in taps

I tried that, but there are not enough complete threads before the surface of the barrel to get the tap going, and I was worried I'd screw up the thread in the softer cast metal of the bayonet adapter. So, I ended up marking the barrel with layout fluid and clamping the adapter in rubber jaws until it was tight. Before I cut it back, I aligned the adapter with the existing bead on the barrel, and scratched the center of the holes with an awl, along with a mark on the barrel just in front of the adapter to get back the alignment after I cut the barrel back. I started filing the grooves with a triangular file to get started, then opened up with rat tails. I kept testing with a punch about the size of the minor screw diameter (the back end of a numbered drill bit). Once it went through, I tried to start a tap but couldn't get it to go in straight, either side. So I kept marking the groove and running a screw in until it started to seize, filing the worn spot. This worked, but wears the screw out. I should be able to get a tap in now to clean it so the final screw's threads don't crush. I don't want to take the grooves any deeper than necessary. Using the thinnest part of the muzzle, I think my lower grove leaves at least 0.026, maybe more but no less. I hope that is enough.