Repairing the Unique
#21
No thoughts on how to repair the feed ramp?
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#22
How about a pic showing a loaded magazine with the barrel in place. We need to see how the rounds are positioned with respect to the ramp.

Tom
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#23
Can do!
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#24
While the forum was down, I did some looking at and thinking about the feed ramp -- I came to believe that even thought the feed ramp and the chassis don't align, that the feed ramp and the magazine were in close proximity and should work satisfactorily. So I started researching failure to feed jams, and most people thought that it was a weak magazine spring issue.

I took it to the range and tried different numbers of cartridges in the magazine. I discovered that I could put 5 rounds in the 10 round magazine, and it would feed correctly. Above that number, and the cartridges would nosedive and jam. That correlated with the information I'd read about weak magazine springs.

I adjusted the angle of the magazine pusher block to emphasize the upward tilt of the cartridge as it reached the top of the magazine.

So I ordered some more music wire from Amazon and experimented with different stiffnesses of magazine spring. The first one I made was so stiff I couldn't fill the magazine with cartridges. A few springs later I made one which I could fill, and it still pushed hard enough to get a whole to feed.

At the same time, I decided to re-wind the ejector spring because it was too tight in it's pocket, and made scraping noises when manually depressed. It works much better now and extracts more reliably with the smaller spring.

At the range a couple of days ago, I put about 100 rounds through it and found that it fed and ejected pretty reliably. I had 3 feed jams in which the cartridge angle would go too high and would stovepipe an un-fired cartridge. Not sure how to solve that.

The 2 new problems that came to light were failure to fire (on probably 20 occasions) and poor accuracy.

My next action steps will be to disassemble, clean, polish and lubricate the trigger and hammer assemblies. Hopefully that will cause the hammer to hit the primers just a little harder.

After that, it's a couple of machining jobs: I want to make a new, taller rear site post, which is in a dovetail. That should enable me to fix the elevation problem, and I can adjust the side-to-side aim by moving the rear site in the dovetail.

The second job will be to bore the front of the slide for a bushing designed to tighten the relationship between the barrel and the receiver. Right now, it's comically floppy.... the front of the barrel moves up and down perhaps 1/8" if you wiggle it.
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#25
OK, after a long time away from the Unique, I've gotten an urge to work on it again.

To my thinking the primary cause of the inaccuracy is that the barrel is quite loose in the frame/slide.

There is a .003 gap between the slide and barrel, allowing the end of the barrel to move slightly less that 1/8".

The basic challenge is to make the barrel & slide fit closer. When the pistol is in battery, the barrel slides over a wide spot in the barrel. The barrel is not permanently affixed to the frame, just held in place with the recoil lugs.

I'm on the fence about how to cure this issue. My initial take on it is to enlarge the slide and install a bushing. However, the hole is an odd shape - It's almost an oval, except the lower side of the hole is a different radius, and has sharp corners. I can only imagine it was broached at the factory.

My alternate thought would be to solder or braze a pad onto the barrel.

Any thoughts or suggestions would be appreciated.

a


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#26
Stand closer to the target?
Hunting American dentists since 2015.
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#27
Shoot at a blank piece of paper. Then, take a Sharpie and draw the target around the hole...
Mike

SB 10K (1976) Rockwell vertical mill (1967) Rockwell 17" drill press (1946) Me (1949)
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#28
Excellent suggestions. :)
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#29
I've been away from MWF forum for a while, but thought I'd drop by with a couple updates.

The Unique now has about 800 rounds through it, and I've tinkered with it continuously to improve feed, ejection & accuracy.

I can't figure out a good way to tighten the fit of barrel in the receiver. The major problem is that the top locating surface is actually the slide. If I take all the slop out of the barrel mounting, the slide won't move. I've pretty much accepted that it's a crappy French engineering shortcut and can't be improved unless the design is substantially changed. I have ideas, but they'd be major, irreversable modifications.

I examined the trigger assembly, and found a couple burrs on different parts which I stoned off, and I put a **very** light polish on the sear faces. I didn't want to move a lot of metal. I also wound a substantially lighter trigger return spring. The trigger work reduced the size of the groups literally by half! It's still not accurate by any means, but it's much better, and quite gratifying to see the results of the work.

Recently, I noticed an upswing in ejection jams, and upon inspection, the ejector had broken in half at the pivot point and disappeared, along with the spring! I was utterly astounded that it functioned as well as it did without an ejector. So, I made a new ejector and hardened only the tip which is in contact with the case. I haven't shot it since, but anticipate it will go back to ejecting "most" of the time. :)
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