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    • #47638
      Goodsteel
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      I have been burning copious ammounts of time on a Winchester model 100 that a customer brought in. It’s an early one, and it’s jamming, leaving the brass in the chamber.

      First thing I did was hone out the chamber bright and clean. I checked it with my borescope and it’s as perfect as one of my custom bolt action chambers. That worked for about four shots, then we are back to square one.

      Next, I noticed that there was an impression in the exctractor cut from years of ripping the extractor off the rims of the brass stuck in the chamber, so I made a shim of the correct size to bolster the cut, then peened the upper edges of the slot down over the shim. Then I took a slotting file and dressed the cut clean and true.

      I replaced the extractor, spring and plunger. No effect.

      Then I bought the Wolff extra power recoil spring and firing pin return spring kit and installed it. No effect.

      Then I doubled up the extra power recoil spring with the inner spring that came on the original rifle. No effect.

      Then I honed the chamber again. No effect.

      I’ve run a good 100 rounds through this rifle (at least) using Remington, Federal, M80 ball and handloads.

      The Remington was the worst and would jam every time.

      Federal jams every 3 shots or so.

      Handloads (42.5gr IMR4895, 168 Honady HP match bullet, LC brass, CCI primers) ran almost flawlessly, but this client is not a reloader, so big fat whoop.

      I have read online that this is a problem that has stumped many gunsmiths and very few people ever get their rifle running right again once it starts jamming like this.

      Other things I checked:

      Gas port: Clear. Not eroded. Drilled in the very center of one of the rifling grooves.

      Hammer: Full power to the spring. Very deep firing pin indentation.

      Gas system and inner workings of the rifle: Clean, clear, not damaged functioning smoothly.

      All indications I have is that the rifle is horribly overgassed. I thought about trying to reach in through the gas block hole and TIG weld the gas port which would shrink it significantly (and may also weaken the silver solder that holds it on the barrel/compromise the seal it has with the gas port/or warp the gas block). Other than that, I see no way to modify the gas system on this firearm.

      It is interesting to me that the 4895 loads ran correctly. I wonder if it was built around old military spec ammunition that is less harsh/thicker brassed than modern hunting ammunition.

      That said, at this point, I’ve spent $150 on parts and ammunition trying to get this rifle running. I made the hardest call I could possibly make last night, and explained to the client that I had failed, and even if I succeeded at this point, the labor, parts, and ammunition cost would be greater than buying a new rifle. I suggested we split the misery and cut bait. I charged him $100, he was fine with that, and I WILL NOT WORK ON THESE RIFLES AGAIN IN THIS SHOP.

      (unless of course, one of you can tell me something that I haven’t thought of.)

      I hate getting skunked. I hardly EVER get skunked, but when it happens, I want to crawl into a hole and pull a rock over on top of it. I take my time and work slow, and usually I can find a solution to nearly any problem and sometimes come up with something that nobody ever thought of, but in cases like this, I feel like I’m stuck in the middle between a company that marketed a janky rifle and a client that wants it fixed.

      What a crapchute.

    • #47640
      kens
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      I just thinking out loud here,

      can you smoke the chamber, then go into the chamber with a proper reamer and wipe the smoke out with a chamber reamer, looking for a tight spot?

      I presume the headspace is OK, but then headspace guages only tell you 1 dinension, from shoulder datum to boltface.

      I would want to know the dimension of all the various diameters and tapers on the body, shoulder and neck in the chamber

    • #47642
      Rattlesnake Charlie
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      Could this have something to do with the burning rate of the powders used? Like the M1 Garand will bend operating rods if slow powders are used as the pressure at the port is still too high when the bullet passes by.

      It could also have something to do with the steel. Might want to try to give the chamber a coat of Dri-Slide.

    • #47643
      Anonymous
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      I would think it is overgased for all the new powders.

      were Model 100 made in the 60’s ? or the 50’s

      M1a Match ammo prob runs no problem or any load that runs in a M1a

    • #47644
      Goodsteel
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      I believe the powder selection is the key. I called Larry Gibson earlier and asked him simply if standard ammo in 308 and 30-06 may have basically changed over the years. I was thinking that the vintage of this rifle may have been key if Winchester had been using military ammunition as a basis of gas system design, or, if all ammunition may have been loaded mil-spec.

      Larry confirmed my suspicions and explained that in the 70s, affordable chronographs started to come out on the market and people started holding the ammunition manufacturers feet to the fire. That’s when they started blending their own powders and hitting certain speed and pressure numbers.

      Larry had the numbers right there on his computer having tested some of the exact ammunition I was using and which had given the worst trouble (Remington Core-Loct 150gr). He said the pressure on that stuff was 55,700 PSI but the time/pressure curve was much slower than M80 ball (which, incidentally ran like a top in this rifle) M80 ball was actually at a higher pressure but the time/pressure curve demonstrated much less pressure at the gas port, which explains why the rifle ran so well with the M80 ball, as well as with my hand loads.

      Kens: Of course I checked the chamber for bulges thoroughly. There were none. And no, a reamer would not be used to check the chamber for high spots. It’s a cutting tool, and as such could easily scratch the chamber or deepen headspace. What I did do, was to take a casing that was stuck in the chamber, dismantle the rifle, and see how it was so hard to put back in there, observe rub marks, and then, measure that casing carefully all the way down for a suspicious bulge. There was no indication of a badly cut chamber, and this issue is very pervasive with many rifles of this make and model. It’s a conundrum that has stumped many, and the fact that I’m sitting here saying it’s stumped me is evidence enough of the difficulty of the problem.

      The thing is, I made the same blunder that all my predecessors have: I assumed the rifle was made to use standard, modern, factory ammunition. It is not.

    • #47646
      popper
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      Gas control is from that cylinder with the hole & slot in it , not the port in the barrel.

    • #47647
      Rattlesnake Charlie
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      Did about 30 minutes of googling and came up with some clips that are pertinent, plus a link to what might be an improved extractor. Additionally, if it is the powder burn speed, and the owner does not reload, I’d try some of the “reduced recoil” factory loads.

      Usually lack of cleaning the chamber and gas system. When this starts to happen the extractor will pound out the groove cut in the bolt lips. We replaced lots of bolts when they were under warranty. A gauge of about .057 to check the space was used.

      Like everyone else said keep the extractor clean and the chamber lightly oiled, and you shouldn’t have any problems with it. I run a lightly oiled patch in the chamber on mine every so often and never had a failure to extract.

      The problem is in the extractor not the ejector. When it gets dirty it will not pull the shell out of the barrel. I talked to several smiths and even posted it on here but everyone told me I could not get any parts for it. So, with nothing to loose, I ripped it apart. You would not believe the crud under the extractor.

      Extractor Kit
      http://www.nulineguns.com/part_part_269_2_21_64.php

    • #47648
      Goodsteel
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      RC, I had the same though about the reduced recoil loads, but I’m done buying ammo for this rifle.

      I installed the extractor kit you linked to as well as a Wolff extra power recoil spring.

      When the chamber is freshly honed, you’ll get about 4 shots out of it before it starts acting up again. In all the “online research” I did, I ran across example after example of guys who cleaned the rifle chamber, ran 4 shots and declared it a success. Such is the fickle nature of internet information.

    • #47649
      Goodsteel
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      Popper, what you say is true, but I know for a fact that the port hole size modifies the equation directly. I’m not monkeying with it in this rifle, but theoretically, it might have been a possible cure.

      I have a feeling that this problem, like so many others has no one cure. Several things would need to change in order to approach the reliability of the M1 or the AR.

    • #47651
      Rattlesnake Charlie
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      From the multitude of posts I read on extraction problems with that gun I don’t blame you for giving up. I don’t ever think it will work with modern factory ammo. Handloads that back off the throttle a bit and using a faster powder is likely the only solution. I did read one post where the guy did that and solved his problem. Only after much aggravation such as you have experienced. He also said he kept the chamber lightly oiled. IMO, the gun was just designed poorly with the extractor setup, and with a change in powders in factory loads it was destined for lotttttsssss of problems.

      On the note of controlling port pressure, I have an aftermarket adjustable plug that vents off excess gas. It is basically a ball bearing backed by a spring, acts as a pressure regulator. Spring tension and port size allow the gun to now shoot trap loads and full power buckshot interchangeably. If you have an extra plug for that Winchester you might try drilling a very small hole to vent gas in the direction of the muzzle to drop pressure in that operating tube. Just an idea.

    • #47652
      Goodsteel
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      That’s actually a really good idea. I’ll pray on it.

    • #47655
      popper
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      That cylinder is made to slide so just shimming farther back will adjust gas.  Just FYI.

    • #47659
      Rattlesnake Charlie
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      An adjustable gas block? That would be convenient. Thanks popper.

    • #47882
      doc1876
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      I have a shirttail relative that told a friend of his that the Remington pump rifle of his needed to be fixed by me as no one else could do it. Long Story short, I got it, and will never work on a gun that starts with R again.

    • #48089
      Mooseman
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      I have experimented with other gas operated rifles , some of my own creation like my .30 Carbine Spire point AR-15 , and Powder makes all the difference in the world as far as cycling goes. the people reloading the .300 AAC have found the same thing…certain powders work , others dont. It has to be the right Impulse/time gas relationship to work properly.

      I did have an FN /FAL come in for repairs that wouldn”t cycle after a couple rounds (Has adjustable gas system from The Factory) and upon careful inspection found a crack in the chamber . replaced the barrel and solved the problem. The crack was almost invisible to the naked eye, but when the barrel heated slightly it showed up clearly and brass would show a line on it.

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