Slugging .22 Rimfire Bores

Discussion in 'Ruger Rimfire Forums' started by SGW Gunsmith, Jan 8, 2020.

  1. SGW Gunsmith

    SGW Gunsmith Active Member

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    My shooting mainly involves .22 rimfire, along with testing various theories concerning this caliber foisted upon the inter-web, and accepted by some as "gospel". Some of the stuff suggested is just too much to chew, let alone swallow, so, I gots to try it for myself, if only to satisfy "that itch".
    I like to slug the bores of my .22 rimfire rifles to get an idea of what their actual bore size is. The best lead slugs that I could find already are attached to the mouth of a cartridge case:

    [​IMG]

    I made up this "inertia" bullet puller from some 1" PVC unions and caps and a ½ inch oak dowel I had laying around. The bottom end of this tool has a gel-type cupboard door bumper in it to prevent deformation of the lead bullet, once the case lets go of it by smacking the puller on a hard surface. I quit counting after removing over 300 bullets with this tool, so I can confidently say it works very well, and most of all SAFELY.

    One of the bullets is lubed up with vaseline and then shoved into the chamber until it hits the leade, just short of the actual rifling. Of course, the bore is cleaned as best as it can be before pushing the slug through.
    What this slugging does, is, it will tell you where you have tight, or open areas in your .22 rifles bore. Lead is a dead metal, so once it gets to its smallest diameter in a bore it will not expand when it passes over a more open bore area. Once the bullet exits the muzzle, I'll measure its diameter with a digital micrometer and record that dimension

    I've done this process even with some of the bulk packaged .22 rimfire ammunition, only to see if I can segregate that ammunition into groups for sizing:

    [​IMG]

    This is a "Paco Kelly" tool used to either bump up, or swage .22 lead bullets still in the cartridge case, up or down to specific diameters, as close as I can get to actual bore size from measurements taken after slugging the bore. The tool also is provided with bullet nose altering spuds that can create semi-wadcutter, or extreme hollow points for expansion testing. Does the process improve anything at all? Well, to some extent, yes it does. I can get some .22 rimfire ammunition to group much better after getting those to a more consistent diameter size than just using them as they come out of the bulk box.
    Now, is this process worthwhile? Only you can decide that for yourself, but I enjoy trying these things with .22 rimfire, so it's fun for me and I get to do even more .22 rimfire shooting when I do this sorta thing.
     
  2. Frontiersman

    Frontiersman Active Member

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    I'll be interested to read your findings. I've done quite a few things like this over the years. No matter what you determine, someone will jump in and argue with your findings. They will cite evidence contrary to your evidence. The hard part is determining whether they actually have verified their beliefs, spreading unverified rumors they like, or just BS to please themselves.

    Even with slugging your bore. One will argue you cannot accurately mic your barrel, you can only slug. Another will argue that lead springs back, and therefore your slugging is not accurate.

    I've determined that people have a tendency to choose what they want to believe, then find evidence to support this belief. You can throw that in many facets of life, whether it be shooting, or faith. It's human nature.

    Some of my best firearms memories are the countless hours I spent trying different bullet and powder combinations, slugging bores, casting chambers, bedding barrels, etc. trying to find the perfect combinations of variations.

    I once shot over 20 different types of .22lr ammo, trying to find which ammo was the most accurate. The only thing I proved, was that every rifle had a favorite.

    Maybe your study will determine why each rifle has a favorite.

    Enjoy your quest. I want to hear how your tools change your results.
     
    SGW Gunsmith likes this.

  3. SGW Gunsmith

    SGW Gunsmith Active Member

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    I know, there are always some "recliner experts" who like to blow smoke. After spending 16 years as a toolmaker doing precision work, I've learned how to use a digital micrometer and then how to measure over diameters with precision gage blocks and an indicator. So, I'll trust my procedures before I trust any of the "web BS" that others follow.
    I do these things for my own knowledge and ultimate use, so I don't bother with any of those who've never even tried any of these procedures, except for one precision shooter and bench rest rifle builder named Bill Calfee. Most of the nay-sayers are not good enough to lick his boots.
     
  4. SGW Gunsmith

    SGW Gunsmith Active Member

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    Anyone who argues that a lead bullet will "spring back", or expand in a bore is only advertising their ignorance about using a lead bullet to get a bore diameter.
    Lead is a dead metal and will only find the tight areas in a bore. It will NOT expand when it encounters a more open area in the bore, it will quickly pass right on through.
     
  5. jstanfield103

    jstanfield103 Member

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    SGW, you would not have a picture of the inside of that puller to post would you ? I may have to put one together myself.
     
  6. SGW Gunsmith

    SGW Gunsmith Active Member

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    The puller is made from ½ inch PVC pipe. The only item inside is at the bottom where the bullet lands, and that involved either a gel or carpet like round pad to protect the bullet. So, it's hollow on the inside.
     
  7. SGW Gunsmith

    SGW Gunsmith Active Member

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    Here's a pic of all the components involved before assembly:

    [​IMG]

    None of these parts are glued in place, only in case a part needs replacement.
     
  8. jstanfield103

    jstanfield103 Member

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    Perfect,

    Thanks so much SGW