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Pinnacle 9mm conv+ S&W 637/642

Discussion in 'Handguns: Revolvers' started by Matt-J2, Jul 28, 2008.

  1. Matt-J2

    Matt-J2 Well-Known Member

    Pinnacle Guns offers service to convert various .38/.357 revolvers to 9mm.

    I'm really considering picking up a 637 or a 642 and having this service done. I think having the shorter rounds on moon clips would make for nice fast reloads. The sort that I could pretend to be a mini(and slower)Jerry Miculek. :p

    Anyone know what sort of rep Pinnacle has? Any inherent problems with the conversion itself? I reckon accuracy would suffer a bit, but then I may never notice given my purposes and the ranges involved. Should a different J-frame be chosen?

    Nothing wrong with .38spc mind you, I just like 9mm. Don't much like autos, though. Heck, maybe I'll get it ported as well, and it can be my 'race gun'. :p

    351 WINCHESTER Well-Known Member

    I question whether an alum. frame will stand up to the pressure of a 9mm load. They are rated for +P which is roughly 20K psi where a 9mm starts around 35k psi.
  3. Matt-J2

    Matt-J2 Well-Known Member

    Oh yeah, hadn't thought about that. I suppose I could go to a model 60 3" instead. Love the way it handles empty, and would probably handle much better when firing anyway.
  4. Brian Williams

    Brian Williams Moderator Emeritus

    I have a 642 that I had Mark from Pinnacle put in a 9mm cylinder from a 940.
    It is a great gun and handles like a mule. I would love to see a scandium frame/SS cylinder 342. It would be a better gun than a 642. I have also fit the 940 cylinder into my S&W 60-4 and it is a much better combination, I love the moonclips and adjustable sights.
  5. Matt-J2

    Matt-J2 Well-Known Member

    Interesting, so I suppose then there's no issue with the 9mm in the alloy frame, or is it because you used the different cylinder?

    351 WINCHESTER Well-Known Member

    I've been wrong before, but like I said the 9mm in standard form generates a lot more pressure than a .38+P or a .38+P+ for that matter. Remember a 9mm in non +P generates about 35k psi while the +P+ from winchester and federal of day's gone by ran about 24k. That's a big difference. I would not do that to my gun. There were many an alloy j frame that were ruined in very short order by the +P+ Treasury load.
  7. earplug

    earplug Well-Known Member

    I for one don't see the advantage in the current J frames, unless this is some type of game gun that allows moonclips for snubs.
    Want more power load the .357.
    9 MM might be ok for a LEO back up to a service gun, if ammo swapping was a issue, but you have mooned them up. Moonclips are harder to carry then a speed strip.
    Its a neat idea without merit IMO.
  8. Matt-J2

    Matt-J2 Well-Known Member

    Well, kind of as a game gun, but for carry as well. Lots of reasons. A box of 9mm is cheaper than either .357 or .38spc, even when reloading. Moon clips aren't too hard to carry especially with the shorter 9mm. I don't place anything in my pockets except the cloth for cleaning my glasses, as I don't like having stuff in them, so the speed strip advantage is gone. Speed strips are certainly a much slower and much more awkward reload anyway, never did like them.
    The .357 certainly adds power and is an easy option to get, but then it also adds quite a bit of recoil, flash, and noise. As far as power goes, I'm personally ok with standard .38spc or mild +p, but 9mm would seem to occupy the slot above .38+p and below .357. Not a bad spot to be, IMO.

    No, I don't think this is a needed conversion or anything, but I certainly think has enough merit to seriously consider.

    Of course, there's always the silly 'I want it 'cause it's neat' factor, which shouldn't be underestimated. :p
  9. g1726

    g1726 Well-Known Member

    I have a 940 that I love, though I do wish it were a bit lighter. I'm really considering getting a lightweight .357 and having them do it.

    The .38 frame can most likely take it for quite a while, but I would have zero doubt in the .357 frame regarding durability.
  10. 351 WINCHESTER

    351 WINCHESTER Well-Known Member

    No doubt the .357 frame will stand up to the pressure and the 9mm with the right loads will give you close to .357 performance w/o the recoil of the mag.
  11. ArchAngelCD

    ArchAngelCD Well-Known Member

    What advantages do you feel you get from a 9mm over a .38 Special +P in a snub nose revolver? With today's bullet technology expansion isn't an issue. This isn't a knock on the M940 or the 9mm round, it's a serious question.
  12. yongxingfreesty

    yongxingfreesty Well-Known Member

    if it were safe, id do it. 9mm is certainly cheaper than 38spl, which is a good thing.
  13. seeker_two

    seeker_two Well-Known Member

    I could see it working. With the current strength steel cylinders, a 9mm conversion should be able to handle the pressures. And the moon-clipped cartridge should mitigate any backthrust since it would have 4 other rounds helping to hold it back.

    Depending on the cost of the conversion, it might be worth it for the increase in ballistic effectiveness, handling, and use as backup for 9mm pistols....
  14. g1726

    g1726 Well-Known Member


    The main advantage for me is ammo commonality. I don't have anything in .38/.357, but do have other 9mm. I didn't want the extra round, reloading dies, brass and components.

    On top of that I do like the moonclip reloading, the shorter length and the performance without the extra flash and bang of a .357.

    I do prefer the mid-weight 124/125 gr bullets, so to me it made sense. If I liked the 158 gr class, I would have no hesitation in getting a .38/.357.
  15. 20nickels

    20nickels Well-Known Member

    The positive ejection and reload of the moonclip would be nice, but I would much rather carry a speedstrip. Hmmmm, why not just moonclip the .38's or the .38 Short Colt which is basically a 9mm? Is anybody making J frame .38 moonclips?
  16. gb6491

    gb6491 Well-Known Member

  17. Matt-J2

    Matt-J2 Well-Known Member

    Pinnacle will machine a cylinder for moon clips as well.
    Cost for the 9mm conversion is $225, cost for just moon clip conversion is $80.
    May just go the moon clipped .38spc route. Haven't decided yet. May not even do that.
  18. ArchAngelCD

    ArchAngelCD Well-Known Member

    You gave all good reasons but ammo commonality would be enough for me. Thanks for your answer...
  19. lanternlad1

    lanternlad1 Well-Known Member

    I had a 940-1. Good gun, but you couldn't shoot +p in it, as the frame was not rated for it. Also, it was a bit heavy, but that helped when you shot it. I have a Ruger Speed Six in 9mm now, and that thing weighs a TON (2.5lbs). I can carry it, but I definitely know its there. It uses half-moon clips, which are far easier to carry than full mooners. I've considered sending my wife's 642 in for conversion, but I've heard there are issues with accuracy then. Anyone know about this?
  20. g1726

    g1726 Well-Known Member

    I really had to look for my 940. I originally wanted an SP101, but couldn't find one. I'd really like to get a 3" 940 or SP101 in the future.

    The S&W 547's are also very tempting, but they command prices that I'm not willing to pay.

    I really think I might pick up a 4" adj. sight .357 and send it off. Anything over 4" is really .357 territory to me, but 4" and under still looks pretty good for 9mm.

    Then again, it would be tempting to have it reamed for 9X23mm and shoot a near .357 equivalent while still being able to shoot the cheap 9X19mm with moonclips.

    Too many projects, too little cash.

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