.300 blk load question

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  • Wiley Jester

    Member
    Aug 18, 2013
    12
    Hello, I found some load data for Hornady 208 grain Amax bullets with AA 1680 powder at 10.7 grains at 2.12 COL. I set my press up for this load and as I was putting the cartridges together it appeared that the bullet was compressing the powder in the cartridge. My question is, will there be an issue with the bullet sitting too low in the case and compressing the powder?
     

    Marauder

    Revolver Addict
    Dec 14, 2010
    1,485
    The Hornady manual has the COL@ 2.250 for that bullet, that would be why you are compressing the powder.. (2.120 to short) Move the bullet out you should be okay.
     

    Flipz

    Ultimate Member
    Mar 11, 2010
    3,193
    I use Hornady 208gr BTHP and 1680 for my 300blk load.

    208gr BTHP
    10.7gr of 1680
    2.230 OAL
     

    TyFromMD

    Ultimate Member
    Mar 31, 2011
    3,804
    Maryland
    I loaded some 208gr a-max with 10.8gr of A1680 with COL of 2.230. Functioned better than any other load out of my 10.5" suppressed noveske build.
     

    Wiley Jester

    Member
    Aug 18, 2013
    12
    I appreciate the feedback. I also have a Noveske 10.5" barrel that I finally got the stamp for last week so Friday was my first outing with it. Everything I sent through it functioned very well, supers and subs. No issues with cycling or the bolt locking back on empty. I have both AA 1680 and Win 296 powders that I shot a mix of Amax 208 and SMK 220 bullets with. I'd like to find a good load with the 208, so I was going to try the AA1680 through it. Load data has not been plentiful, which is why I was excited when I found the thread here:

    Http://www.300blktalk.com/forum/viewtopic.php?t=84533

    The author recommends a COL of 2.12, but from your responses it sounds like I am better off going with something closer to 2.26. One question, I have loaded 10 rounds at 2.12, is it safe to shoot those loads or is the lack of "space" in the casing going to cause a problem? I ask because I have read about things that impact pressure and I'm not clear as to whether this would be a hazard.

    I hope this isn't a silly question, appreciate any feedback.
     

    friendlyhippo

    Banned
    BANNED!!!
    May 7, 2015
    592
    Glen Burnout
    Hornady factory 208 subs measure 2.180.

    They may not be utilizing AA1680 powder though. They're probably using something more dense that doesn't fill the case as full, so there's more room for the bullet to seat.

    I never could get my hands on any 1680, so I did a little digging and learned IMR4198 is actually a great powder for subsonics. With a Primary Arms 1-4x I've managed about 1.25-1.5" at 100 yards with 5 208 AMAX per group, using 10.3 grains (10.5 was occasionally supersonic, but just ever-so-slightly so) of IMR4198.

    The other pistol powders I tried (H110, Lil Gun) just wouldn't fill the case enough to get reliable ignition AND stay subsonic. I often had an upper receiver full of unburnt powder. The switch to 4198 fixed that for good.


    FWIW, my 300AAC utilizes a 10.5" barrel.
     

    Mdeng

    Ultimate Member
    Industry Partner
    Nov 13, 2009
    8,568
    Virginia
    Great timing. I just ordered 300 208 grain Amax bullets from Midway. Hopefully they will be a good hunting bullet for the piggies in NC.
     

    ironpony

    Member
    MDS Supporter
    Jun 8, 2013
    7,191
    Davidsonville
    I have been loading 1680 all week and 208 Amax 11.2 gr. 1680 @ 2.155 OAL gave me 1060 fps avg out of 10 SD 18.3 Should I slow it down a little? CCI 450 magnum primers. The best I can tell is the bullet does touch the powder but not enough for me to be concerned. (just checked)
    Lothar 10.5 " barrel suppressed.
    Please let me know if anyone has concerns with this data? I'm still learning. :)
    Very accurate load for me!! I've seen good groups by others before but did not think I could do this leaning over an atv shooting for chrony data. My next barrel will be the same make.
    Is it right that I have read that a compressed load can bulge a case?

    OH, 4198 I found leaving unburned powder in the lower that is the reason I switched to mag primers and same problem. As mentioned, great powder though. I like 5744 as well.
     

    Sticky

    Beware of Dog
    MDS Supporter
    Mar 16, 2013
    4,501
    AA Co
    Compressed loads should not be an issue. I loaded some of the hornady 208gr match boolit (poly tipped) to 2.150 and over 10.7gr of 1680 it pushed it slightly supersonic (1075-1100fps), so I need to drop it down a bit (10.5" pistol)...

    I have shot compressed loads in bottlenecked cartridges with no issues whatsoever.. even load data manuals will show load densities exceeding 100% on the upper end with many powder/bullet combinations.. ;)
     

    BradMacc82

    Ultimate Member
    Industry Partner
    Aug 17, 2011
    26,177
    Lil Gun under a 240gr cast round doesn't do half bad, I don't recall the charge weight the owner was using, but we did notice that on a 80 degree day with the rounds left in the sun they started showing pressure signs/going supersonic.

    He got to find out how much fun a popped primer can be. Primer got wedged in the cam pin slot on the BCG, was kind of fun pulling the rifle apart to remedy that.
     

    BradMacc82

    Ultimate Member
    Industry Partner
    Aug 17, 2011
    26,177
    Another lesson learned - if the primer seats without much effort, toss that worn out brass.
     

    lmorrison17

    Active Member
    Feb 1, 2008
    187
    I have not been able to get 1680 either.

    Tried H4198, cci 450 I get unburnt powder too and BHO is iffy.
    Accuracy was not quite what I was looking for either.

    Tried 4227 and H110 too but could not achieve reliable functioning and stay subsonic.

    Rem. factory 220 subs functioned and BHO but shot a 5" group at 100yds.

    The Hornady factory 208 subs shot great though.

    I have some 208's left but I shelved the subsonic project till I can get some 1680.
     

    9 er

    Member
    Jan 10, 2021
    2
    I have 8# of A TiteGroup and Lee 200 gr. cast powder coated WW bullets... what would be a good sub load? ThanX
     

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