need help understanding 40/9 conversion

Discussion in 'Glock Forum' started by sawfiler, Jul 26, 2012.

  1. sawfiler

    sawfiler New Member

    my edc is a gen3 27. I'm thinking of adding a 9mm conversion barrel. but how does the extractor and ejector even work with a smaller case? I can understand how a 357 sig would work but seems to me smaller 9 case would be problamatic? also will it be as reliable as a G26 when its all said and done?
  2. jonm61

    jonm61 New Member

    It's a 1mm difference in case size. .40 = 10mm in size. So, they work, and many claim they're 100% reliable, but from the beginning of conversion barrels there have been reports that they are not reliable enough to stake your life on.

    People are now also saying you can, again for range purposes only, use the .40 magazines to shoot 9mm. I, however, have heard of feeding issues with those as well and wouldn't stake my life on it.

    It will not, IMO, be as reliable with as a G26 unless you change the extractor and ejector, and get 9mm magazines.

  3. dwcfastrice

    dwcfastrice Well-Known Member Lifetime Supporting Member

    They do work. It's advertised as just a "drop in". I have one for one of my G23 gen 4s. I left the extractor and ejector alone. I'll change them out eventually. But have no issues with them now.

    For 100% reliability, though, you'd want to change out the extractor/ejector and then grab a couple of mags to reliably feed the 9mm round.

    There are folks who feed 9mm out of the 27 mags with no issues, but I won't go that way personally.

    Unless you got it working 100%, i wouldn't convert my EDC to the 9mm. HOwever, for practice and working on trigger mechanics and such, it is one of the best investments you can make.

    ***Edit***Jonm beat me to it.

  4. iamthedood

    iamthedood The dude: "This aggression will not stand, man."

    ^^ what about putting a stock glock g33 barrel on it (chambered in .357 sig) I've seen it done succcessfully in a g22 w/ a g31....

  5. Did you also keep the 40. recoil spring?
  6. dwcfastrice

    dwcfastrice Well-Known Member Lifetime Supporting Member

    I did for a while. I ended up swapping that out. My LGS/range has an Armorer on sight and he keeps the parts in stock.

    With the stock .40 spring i wasn't haven't any issues, I swapped out the spring for the same reason I swapped out the mags.

  7. Got it, thanks for the reply. I'm only going to be using it for range only.
  8. dwcfastrice

    dwcfastrice Well-Known Member Lifetime Supporting Member

    Try it without the spring and see if it works out for you. If it's just a range gun for cheap practice, i'd ONLY rub the barrel.

    That way, if you have feed or jamming issues, etc., you get to practice clearing, as well. You never know if/when you'll malf. when you need the weapon the most. So being able to practice at the range is a nice "Feature", albiet unintentional feature.

  9. Tape

    Tape New Member

    I would not recommend any conversion, the only conversion I would recommend is buy that weapon. When you buy the barrel you have bought a third of a new glock.
  10. jonm61

    jonm61 New Member


    .357Sig/40S&W conversions are different, because the .40 is the parent case for the .357Sig, so the rim and lower case is the same. Same extractor, same ejector, same magazine.
  11. It's the same weapon when going from G23 to 32 barrel. The followers are different in the magazines but otherwise, the extractor, ejector, etc are the same. The stamped .357 is different though :eek: Why buy an exact replica except for the barrel and magazine followers?? A 9mm conversion, then yeah, I would use that for range only. Of course, I'm no expert so if anyone knows different, please correct me.
    Last edited: Jul 27, 2012