Idea for sub-caliber training ammo

Discussion in 'Ammo' started by gunsmoker, Dec 23, 2017.

  1. gunsmoker

    gunsmoker Lawyer and Gun Activist

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    I'd like to see some company produce some special .38 / .357 chamber inserts that take a primer on the back end, and have a .177" bore into which you'd load a .177 lead pellet of your choosing. No gunpowder needed.

    The purpose of this would be to have cheap, low-noise, low-powered training and backyard plinking ammo.

    These sub-caliber inserts would be good for practicing drawing quickly and getting a hit on the target ASAP. They wouldn't be good for pinpoint accuracy, but minute-of-bad-guy. I'm not sure if they'd even need to be rifled. Let's say "yes" but with shallow rifling, so that it doesn't take a lot of pressure to push the pellet down through that short (1") rifled bore.

    You could reload them yourself with simple hand tools. A little stand and shell holder, a hand-activated primer press a polymer dowel and a tap hammer to seat the new pellet, etc.

    I'd probably want to have 50 such chamber inserts, so that I could reload and shoot several cylinders full of these before I had to stop shooting them (or take a break and spend some time reloading them).

    Unlike dry fire practice, this would give you a real projectile that impacts the target to give you feedback about your aiming /pointing ability.

    For semi-auto calibers, they could make the chamber inserts with a long rounded-tip section to replicate the profile of a live round. I guess you'd be limited to just drawing and firing a single round, if you want to keep the training realistic. Because if you wanted to take a second or subsequent shot, you'd have to reach up and manually work the slide. You could have your magazine loaded with these dummy rounds, pre-loaded with pellets. They should feed and extract and eject fine, as long as you pull the slide back by hand.

    I'm thinking this product would appeal more to wheelgun shooters, not only for the ability to shoot the weapon in the normal SA/ DA mode, but also because if you are working outdoors over grass or mulch, you may lose some of the cases that are ejected from the semi-auto, when you're not paying attention to where they fall, and you're instead focusing on your target.
     
    AtlPhilip likes this.

  2. gunsmoker

    gunsmoker Lawyer and Gun Activist

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    Cost. $400 for a set of these to use in my .38 snubby revolver just isn't affordable.
    And then there's the issue of battery life, and corrosion from leaking batteries, and the hassle of changing batteries (Lasers use a lot of energy), and the frustration of getting any small electronic gadget to work right.

    If you buy one of these, that's a reasonable investment money-wise, but then you'd only get one laser-sighted shot. You'd have to open and move the cylinder by hand to get your next laser shot.
     
  3. gunsmoker

    gunsmoker Lawyer and Gun Activist

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    I've fired a pistol that had plastic cartridges that used the power of just a magnum primer to push a 10mm plastic paintball pellet at over 400 ft/ second. It worked great except the plastic cases got brittle with age, and after a few years in storage most shells cracked upon being fired.
     
  4. zetor

    zetor Gaston beat up John

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    A primed case fired in a revolver pushes the primer out against the breech face and makes it very hard to rotate the cylinder. Pull a bullet and try it.
     
  5. gunsmoker

    gunsmoker Lawyer and Gun Activist

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    Hmm, that's something to consider.
    Maybe enlarge the flash hole?
    Maybe make a two-piece chamber insert, with a captive floating striker where a factory primer would be, but that merely carries the impact of the firing pin forward to smack the real primer in front of it, which is right under the pellet.
    This would reduce the barrel length of the unit by maybe .33 of an inch, but it could still be done. That might up the cost to make boxes of 50 prohibitively expensvie though.
     
  6. gunsmoker

    gunsmoker Lawyer and Gun Activist

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    P.S. Cowboy action shooters have been using wax bullets for years.
    Those loads don't have enough pressure to stretch the case and seal it to the cylinder walls.
    Why don't THEY have primer-back-out problems?

    *** EDITED : They drill-out the flash hole and use those modified cases only for the wax loads, never again for normal loads with real bullets ****

    https://www.americanrifleman.org/articles/2010/4/12/how-to-make-and-reload-wax-bullets/

    I've personally used a few hundred CCI plastic bullets in plastic cases (.38 special caliber), powered only by primers. They never backed out and dragged on my revolver's frame. Not that I noticed, anyway.

    speer-plastic.jpg
     
  7. AtlPhilip

    AtlPhilip Proud GCO member.

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    Why does the full load with a bullet not do the same thing? It would seem the pressure would be orders of magnitude higher.
     
  8. gunsmoker

    gunsmoker Lawyer and Gun Activist

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    I've "heard" ( but I have my doubts) that during the firing of a large-caliber revolver, the brass case at first sticks to the inside of the cylinder when the pressure level is spiking and the heat is high.
    Then, as pressure drops and the heat dissipates by spreading across more and more metal, the case and that particular cylinder cool enough to allow the case to back out of the cylinder and slam up against the breech face, around the gun's firing pin hole.
    That's why you see a case-rim sized ring around the firing pin hole in well-used revolvers.
    This would also re-seat the primer, IF it had backed out a bit prior to the case itself moving.

    What I really don't understand is, if that's how this process happens, how does the case get BACK fully seated into the cylinder?
    Is it just the pressure of the firing pin, still extending forward (the trigger hasn't been released or reset yet), pushing the case forward by still touching the dented primer?

    I'd like to see a real close-up of just the back of a revolver cylinder when firing, with a high speed camera, and the footage slowed down to slo-mo playback.
     
  9. zetor

    zetor Gaston beat up John

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    Because the case gets pushed back hard against the breech face. Really hard.
     
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  10. zetor

    zetor Gaston beat up John

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    That is a good question. I have had 44 cases that I had to push on the ejector rod pretty hard (harder than the pressure exerted by the firing pin) to eject them but don't remember any hangups with the case head dragging as the cylinder was indexed.