In order to participate in the GunBroker Member forums, you must be logged in with your account. Click the sign-in button at the top right of the forums page to get connected.

Interchangability of 9mm / .357 bullets

je2140je2140 Member Posts: 225 ✭✭
Can you interchange 9mm bullets in .357 or .357 in 9mm (copper or lead) ?
I think 9mm is .356. Will .357 cause pressure problems in 9mm?
Will 9mm in .357 be in-accurate because it is .001 undersize?


  • cokedaddycokedaddy Member Posts: 18 ✭✭
    edited November -1
    Howdy, many years ago I did use 9mm [.355"] Sierra JHCs in a S & W Model 19. Didn't have a chrony back then but they were really steaming, don't have my notes ifo me but to answer the ? they were pretty accurate. That said I would avoid the reverse, i.e. loading .357" boolits in a 9mm. You might get away with it with lead bullets but why take the chance? IMHO[:)] A funny side note re those loads, a buddy and I were 'chuck hunting and came to a pond with a big bullfrog at the surface. My pal says see if you can hit him. No earplugs man what a noise. Well after the shot we were surprised not to see him come floating back up. My buddy says you must have missed. We take a step and then SPLAT!! We laughed so hard I almost got sick. That thing musta have went up 60' for it to take so long to hit the water.
  • je2140je2140 Member Posts: 225 ✭✭
    edited November -1
    Thanks for the advice
  • fire for effectfire for effect Member Posts: 121 ✭✭✭
    edited November -1
    Yes, with the proper precautions they are interchangable. You need to reduce the powder chargewhen using a .357 in a 9mm, because the increased friction will increase pressure. You can get a bullet resizer from Corbin Manufacturing which will swage the .357 bullets down to .355 and solve the problem altogether. thgis give you such a range of bullets to choose from. Not only all of the 9mm bullets to choose from but also all of the .357 bullets as well.

    Using 9mm bullets in .357 is a trick used by the old Super Vel Company. They would use bullets two thousandths of an inch smaller than normal to get the increased velocities.
Sign In or Register to comment.