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G17 Best OAL?

Discussion in 'Reloading' started by Shadetreeman, Mar 31, 2011.

  1. Shadetreeman


    Mar 23, 2011
    So how do you guys come up with a best OAL for you gun. I know it changes from one bullet type to another but let’s just say you can chamber a 9mm 124 fmj with a OAL of 1.175 and it runs good in the mag. But the load data has 1.090 can you go that high or is it just too dangerous. Also isn’t the best accuracy at when the bullet is just off of the riffling in the barrel. I’m just saying holy crap there is a lot of contradicting info out there.
  2. cowboy1964


    Sep 4, 2009
    I load empty cases to experiment with OAL when I first start loading a particular caliber. I start with an OAL towards the max end and see if chambers correctly. If it does I go with that. I'm very paranoid about overpressure as I want to load my rounds a little on the warm side and the Lee Pro-Auto Disk isn't exactly super precise (I've seen variations of 5% round-to-round).

    I use 1.155 or so for 9mm 124 plated (Berry's Bullets) and it's been working perfectly. I also compared this OAL to the Winchester NATO 124+P round and it's pretty much at 1.15 too.
    Last edited: Mar 31, 2011

  3. Patrick Graham

    Patrick Graham Footlong Jr.

    Sep 7, 2001
    Kokomo Indiana
    I try to stay in the 1.16" to 1.165" area.
  4. fredj338


    Dec 22, 2004
    That is over SAAMI spec & leaves little bullet left inside the case. There is zero accuracy advantage in handguns loading into the lands & 1.175"OAL won't run reliably in most mags. The reason OAL is all over the place is bullet shape, they vary quite a bit from manuf to manuf.:dunno:
  5. Shadetreeman


    Mar 23, 2011
    So if you loaded a 124fmj at 1.090 with just say 4.5grn, could you use the same amount of powder with one loaded at 1.165, or would you need to up the powder a little.
  6. shotgunred

    shotgunred local trouble maker

    Mar 1, 2008
    Washington (the state)
    For a glock G 17 stick close to 1.125
  7. Boxerglocker

    Boxerglocker Jacks #1 Fan

    Mar 6, 2003
    Lynnwood, WA
    For a 124g FMJ 1.135 used to be my target OAL for my Glock 9mm's, I started loading it longer to 1.140 to accomodate my other 9mm guns particularly the Spartan. I bumped up the charge .1g to compensate and keep me above 130 PF.
    Last edited: Mar 31, 2011
  8. fredj338


    Dec 22, 2004
    The only 124gr FMJ that would load that short would be a tuncated cone. To answer your question though, if you load the same bullet that much shorter, then pressures & vel will go up, so a reduction of powder charge would be needed. Check my blog, I did load workups w/ 9mm over the chrono & shortened the OAL. YOu can see the realationship to OAL vs vel & all things being equal, vel = pressures.
    Last edited: Mar 31, 2011
  9. ron59

    ron59 Bustin Caps

    Jan 3, 2009
    Smyrna, GA
    I agree with Fred... I believe 1.169" is the MAX specified length. I don't run anywhere near that long.

    I load my 147s in the 1.125" range.

    My approach is to gather data from multiple places. I bought one of those blue "Load Data" books for 9mm, which lists data that is basically collected from the manufacturer's web sites, and possibly even the loading manuals. I also look here and Enos' site.

    I try to find a "recipe" for the length I desire, and validate that against other sources. I also have a chrono, so it's easy to start low, and work the load up until I've reached my desired velocity, having confirmed that is a safe range with the powder (not near max).