Rechambering .22 LR to .22 Mag

Discussion in 'Gunsmithing Forum' started by Skribbane, Mar 1, 2010.

  1. Skribbane

    Skribbane New Member

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    Hello all,

    I have a question from across the pond - I'm a student in the UK, so I'm nowhere near as acquainted with terminology as you folks, please forgive me if I'm incorrect in some details :)

    For a recent assignment, I need to reconstruct a crime scene. One of the guns found, a Smith and Wesson 22A, from trajectories of shots, seems responsible for the firing of Winchester Super-X .22 Mag. As far as I am aware, it is not possible for a .22 LR such as the Smith and Wesson to fire .22 Mag rounds, because of the increased length and girth of the cartridge case?

    My question is whether it is possible to rechamber the Smith and Wesson so that it is capable of firing .22 Magnum rounds? If this is possible, any indicator of the complexity of the procedure would be incredibly useful (as this assignment is set in Britain, so the process would be DIY rather than by a professional).

    Thanks ever so much for any help you can give me,

    Jennifer
     
  2. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    IF the round were to be manually loaded (one at a time), it might be possible. The magazine length would preclude the chambering of a subsequent .22 Mag round. It could chamber a follow up .22 LR round, but that round would likely split when fired and not extract/eject properly because of the oversize chamber dimensions.

    The other problem is the blow back mechanism is set up for the recoil impulse of the .22 LR. The Magnum cartridge would blow back at excessive velocity causing the case to be ejected farther than normal. It also would likely open prematurely causing a blown case and possible damage to the gun.

    The bolt could be modified to make it heavier to prevent the premature opening, but that would be an expensive time consuming process.

    Was a fired case recovered? If not then the shooter could have modified the gun to lock closed on the loaded round. This would prevent the blown case scenario and eliminate the evidence at the scene.

    Was a bullet recovered? Is it consistent with the Winchester .22 Mag bullet? Have you looked at the trajectory of a hyper velocity .22 LR round? Look at the CCI "Stinger" round and compare trajectory at handgun velocities. The two may be very close as the Magnum round will lose some of its oomph in a shorter barrel, whereas the LR "Stinger" will not lose as much.
     
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  3. Highpower

    Highpower New Member

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    I would also be interested to know what the weight and groove diameter was on the fired bullet, if in fact one was recovered - considering you would have to squeeze the larger bullet (.224) through the smaller (.222) LR bore.
     
    Last edited: Mar 1, 2010
  4. stalkingbear

    stalkingbear Well-Known Member

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    As usual, I was beat to the punch. The Winchester Super X is a true jacketed bullet-unlike all .22LR bullets. It would be remotely possible to convert the S&W model .22A to fire the .22mag in a single shot manner BUT it wouldn't be easy and in NO way be practical. The blow back operation would be a major stumbling block in setting it up for .22 mag pressures. Also the bore would have to be slightly enlarged (both lands & grooves).
     
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  5. Skribbane

    Skribbane New Member

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    Hi everyone,

    Thanks for your swift replies! In response to robocop10mm and Highpower, both fired cases and bullets are recovered and definitively stated to be the Winchester Super-X Rimfires - these, to be exact: Winchester Super-X Rimfire Ammunition X22M, 22 WMR, Full Metal Jacket, 40 GR, 1910 fps, 50 Rd/bx

    If the Smith and Wesson fired rounds at all, it needs to have fired two in quick succession, which has to be impossible, taking your collective experience into consideration! I guess I need to rethink the sequence and find an alternative explanation and another (unrecovered) gun... I wonder what the likelihood of someone owning a Grendel P30 in deepest Devon is! :D

    Many thanks all,

    Jennifer
     
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  6. Skribbane

    Skribbane New Member

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    Sorry, I seem to have double-posted that reply.

    As an additional query, if any of you are professionally involved in gun modification and you'd be willing to put your name to the above information, would you send me a private message? It would be great to get a "personal correspondence" into the final piece of work if at all possible :)

    Jennifer
     
    Last edited: Mar 2, 2010
  7. jdsingleshot

    jdsingleshot Active Member

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    With the gun at the scene, the obvious thing to do is check the chambering to see if a WMR would fit. If it doesn't, then you have to find out whether the crew that set up the scene know enough about firearms to use that weapon purposely--in which case the chambering is a clue--or if they did it in ignorance.
     
  8. Txhillbilly

    Txhillbilly Well-Known Member

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    This thread is over 9 years old!
     
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  9. schnuffleupagus

    schnuffleupagus Well-Known Member

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    Likely the young forensics student has become a grizzled veteran of the mean streets by now.

    Occams razor says....nah.
     
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  10. c3shooter

    c3shooter Administrator Staff Member Admin Moderator Lifetime Supporter

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    JD- check date of original post.
     
  11. MisterMcCool

    MisterMcCool Well-Known Member Supporter

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    I gave robocop a like :(
     
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  12. Txhillbilly

    Txhillbilly Well-Known Member

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    He's probably looking down at you laughing his azz off!
     
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  13. jdsingleshot

    jdsingleshot Active Member

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    Not a lot of choice among new threads. Pretty slow news day.
     
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  14. SGWGunsmith

    SGWGunsmith Well-Known Member Supporter

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    3,607 **NEW** posts, and that's not enough to choose from?
     
  15. jdsingleshot

    jdsingleshot Active Member

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    I should have said threads. The forums I watch have had maybe half a dozen new threads in the last month. Not a problem, I just go digging and sometimes don't notice that an interesting thread is moldy.
     
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  16. MisterMcCool

    MisterMcCool Well-Known Member Supporter

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    @Dallas53 makes that many posts a month
     
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  17. SGWGunsmith

    SGWGunsmith Well-Known Member Supporter

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    Well, I can see where that would be a very "boring" place to visit. I'd like to see more folks like yourself leave those with doldrums, and come aboard here. Most, except for a very limited few, can contribute very well to the knowledge base that this site is REALLY about.
     
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  18. Sniper03

    Sniper03 Supporting Member Supporter

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    Skribbane

    Here is another interesting piece of information from Smith and Wesson.

    Product Under Safety Recall Notice

    Model 22A Pistols
    Description of the Hazard
    Smith & Wesson has identified a condition that may exist in certain model 22-A pistols. Based on our ongoing product review, we have determined that the slides of certain pistols manufactured from August 1, 2008 to February 19, 2009, may not meet the design specification. This can create a situation where insufficient headspace exists creating a risk of unintended discharge.
    * Being that the 22 WMR (Mag Case is longer than the 22 Rimfire. This would even complicate the issue of being able to effectively fire a 22 mag in a 22 standard chamber.
    If the head space was incorrect in the pistol. And as stated even if the 22 Mag could be fired in the regular 22 chamber the blow back function of the pistol would also cause a cycling issue. Caused by the excessive pressure between the two.
    So I doubt very much that the standard S&W 22-A fired the 22 Mag. Round in question?

    30
     
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  19. SGWGunsmith

    SGWGunsmith Well-Known Member Supporter

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    Pressure is the same between the .22 LR and the .22 Magnum rounds. The magnum rounds just use a slower burning powder. What would affect the slide drastically, is the "recoil impulse energy" difference between the two rounds, and how that affects the slide/bolt.
    That's one good reason why Ruger does not ( ever ) recommend shooting CCI Stingers at 1640 FPS in any of their Mark pistols. I have a Ruger bolt stop pin that I replaced from a Ruger Mark II Target pistol that is actually bent from the bolt pounding into it. The young owner admitted that all he shot was Stingers. The bent bolt is not extremely obvious, but it is bent. The damage that is quite obvious is the elongated bolt stop pin hole in the top of the receiver. While the bolt stop pin is easily replaced at low cost, the receiver is much more costly should that practice continue.
     
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  20. Txhillbilly

    Txhillbilly Well-Known Member

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    More like in a week. As you well know,he never stops talking while on the phone and never quits typing when on a forum. He's always been one hell of a friend,so I gotta cut him some slack.