Monday, February 10, 2014

Monday Gunday: Amateur Gunsmithing

So, a while back (June 2013 to be precise), I took a young man -- the son of a family friend -- shooting. He did very well for his first time at the range, shooting better than I did when I first went shooting. (I took this as a compliment on my skills at instruction.)

This was him at 25 yards. 

Towards the end of our session he was complaining that the rifle (Rev, my bolt-action .22) wasn't properly feeding the rounds and that the nose of the bullet was getting caught on the upper lip of the chamber. I wasn't terribly surprised to hear this; I've had this problem with Rev before, and it was pretty damn expensive to fix.

This time, I was determined not to go through a month-long process of waiting for some semi-retired gunsmith to allegedly "fix" my rifle. Instead, buoyed by my success at amateur gunsmithing when I modded my Mosin-Nagant, I thought to myself, Fuck this noise, I'll figure out what's wrong with it and fix it my own damn self. 

The first step in fixing it, of course, was figuring out why it was doing what it was doing. In my family, this is known as "knobdicking," and thus I knobdicked with the action to see if I could determine what was wrong. 

The bullet isn't nosing in like it's supposed to, I mused, so therefore there's a problem with whatever makes it nose in. What here looks like a nosey-innie thing? Ah, I bet it's this strange little flange thing sticking into the receiver just in front of and on top of the chamber. Let's fiddle with it a bit, shall we?

Huh. It's wobbling. I would think that this kind of thing shouldn't wobble. Can I make it stop... oh, look, it seems to have broken at the point of wiggle. Well, THAT can't be good. I'm 99% certain it shouldn't do that. I believe I've found the defective part!

Suitably encouraged -- seriously, I've never been happier to have found a broken part, because for once I knew exactly what was wrong, and it looked inexpensive -- I went online to see if I could determine the name of the broken wobbly flangey thing. 

God bless Numrich Parts Corp. They had a handy exploded diagram of my rifle, and I was able to determine that the broken part was called a "bumper" and that it cost all of $2.35 (plus shipping). 

Hooray! I ordered the part, and when it arrived I eagerly took my rifle apart to install it. Okay, huh, it looks like this hinge-y bit here locks into a crevice on part 18 -- that's the barrel -- so I just need to detach the barrel from the receiver. Okay, it looks like it's held in place by two screws. Okay, no problem...

Problem. They aren't screws, they're pins. You have to drift pins out with a hammer and a punch, right?

I don't have any pin punches. Damn. Off to Amazon I go...

After getting advice on Facebook for what I needed, I went shopping and came back with a Wheeler Universal Bench Block and a set of pin punches. This is when I definitely went down the rabbit hole of being a tool owner

Fast forward past the hammering and the obligatory swearing, and we get this: the receiver sitting on the bench block, the (finally!) detached barrel below it. 

New bumper on the top, old broken bumper on the bottom, broken piece extracted from detached barrel to the right. 

New bumper, freshly installed. 

More hammering (and swearing -- the swearing part seems mandatory) and I had the barrel re-pinned to the receiver.  Now for the moment of truth:  does it work?

Of course it works. This isn't rocket surgery we're talking about. Hell, this isn't even true gunsmithing; this is basic disassembly/reassembly. A trained ape could do this (probably easier than I could); actual gunsmithing takes actual knowledge and skill.

Not only do the bullets nose in every time, I seem to have conquered Rev's ammunition pickiness: he'll now eat any .22LR round I have. The bolt is a bit sticky when ejecting the spent cartridge, but I imagine that's just newness and it'll smooth out before long. My only real concern (and this is where the input of real gunsmiths would be appreciated) is if the bumper is going to chronically fail, because if so, I should probably buy a half-dozen or so, just in case.

So, compare and contrast:
  • When taken to a gunsmith:  $50 parts and labor, and no access to my gun for a month. 
  • When I did it myself.: $44.33 in parts (plus whatever shipping was), but I got to keep all the tools, and it was fixed within 2 weeks. 

Winner: Doing it my own damn self.  Even though the difference in price was negligible, keeping all the tools was a definite bonus (and I've used all of them multiple times since then), and of course I got the satisfaction of doing it myself and learning something new. Useful idiocy, ho!


  1. Excellent job fellow knobdicker!

  2. We are tool using apes, that implies tool owning if you think about it.

    Good work on the repair!

    Buy another bumper right away and that one you just installed will never break again.

  3. You have no idea how relieved I was to discover that it's an actual slang term other people have heard about and not just a dirty-sounding piece of familial jargon.

  4. What McThag said. Plus, everybody knows that the benefit of doing projects is that you have to buy new tools to do new things.

    Oh, and congrats on the fix! Cool to be able to do that, isn't it?

  5. I've proved that exactly with VW Beetles and throttle cables.

  6. Never heard that term for it before. Going to remember it, though.

  7. And yeah, well done

  8. Should have polished the feed ramp with a Dremel.

  9. I'm honestly not sure if you're being serious or not. Me with a Dremel is a lot like the monkeys at the Monolith at the beginning of 2001.

  10. I agree with Tamara. There is a polishing attachment that works great for shinning firearms' feed ramps. It looks like a white cone on a stick. All of my guns have their feed ramps polished. I don't have many failures to feed.

  11. Huh. I didn't even know that was a thing.

    OK, I can do this! I'm pretty sure I can't do any damage with a polishing tool. ;)

  12. Okay, which polishing point would you recommend -- 462 or 463?

  13. I was being entirely tongue-in-cheek, in that your average gun owner responds to any cycling difficulties by butchering the feed ramp with power tools. :)

  14. Next time you feel down in the dumps, pull this post out and reread it.

    And remember there are a lot of people out there who can't even use a screwdriver without stabbing themselves.

    Well done. :)


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