close

Privacy guaranteed - Your email is not shared with anyone.

PF safety margin for an IDPA load

Discussion in 'Reloading' started by Wash-ar15, Jul 31, 2010.

  1. Wash-ar15

    Wash-ar15

    Messages:
    1,664
    Likes Received:
    0
    Joined:
    Sep 15, 2007
    Got to chrono a load of solo 1000 and 147gr PD FMJ @ 1.14 today. out of the 10 rounds the high/low was 844/894 for 869. 844 is just below the PF while the average would be at 127. this was done on a 65 degree day.

    With the 869 average,should i be concerned about not making Pf since it so close to the borderline? should i bump it up the 4.0,which is the next cavity in the Lee disk?
     
  2. MSgt Dotson

    MSgt Dotson

    Messages:
    3,268
    Likes Received:
    11
    Joined:
    Sep 30, 2006
    127 PF is pushing it for powders with a +/-25 fps variation....; if your load were to be chrono'd for a match for which you traveled 3 hours to get to, you'd be mighty upset when it gives 124,990 (they don't round up!) if they happen to choose a handful of your weakest batch, simply thru bad luck....
     

  3. dsmw5142

    dsmw5142 NRA Member

    Messages:
    1,115
    Likes Received:
    0
    Joined:
    Oct 2, 2007
    You could probably shorten your OAL and give it a bit of a bump. I had some 180gr .40's loaded the other day that were @1.140 and I shortened them to 1.125 and it bumped me from 164-165PF up to 169-170PF.

    I would probably bump up the charge a bit though. Solo is reverse temperature sensitive. On a bit warmer day, you'd be hosed. Why take the chance? I really can't tell much difference between a 125 and a 135PF load in my G34.
     
  4. Hoser

    Hoser Ninja

    Messages:
    2,435
    Likes Received:
    120
    Joined:
    May 22, 2002
    I load to either a 130 pf or a 165 pf, if the accuracy is there.
     
  5. Colorado4Wheel

    Colorado4Wheel

    Messages:
    14,993
    Likes Received:
    221
    Joined:
    Nov 2, 2006
    Location:
    CO
    130 Pf. At that PF none of them should be below PF. One complete disc size may be too much extra powder. I load Solo1000 down to 1.080 with my 155gr lead. Also, the spread should shrink when you bump the pressure with that powder.
     
    Last edited: Aug 1, 2010
  6. ron59

    ron59 Bustin Caps

    Messages:
    6,927
    Likes Received:
    23
    Joined:
    Jan 3, 2009
    Location:
    Smyrna, GA
    I agree with your "target" PF being 130PF... that gives you plenty of leeway when it comes time to test your ammo at a match.

    I have also used Solo-1000 under a 147gr bullet. At ~125PF the rounds were VERY inaccurate. At 130PF... pretty dang good IMHO. Those heavier bullets need some "zing" to them for accuracy.
     
  7. shotgunred

    shotgunred local trouble maker

    Messages:
    9,125
    Likes Received:
    1,401
    Joined:
    Mar 1, 2008
    Location:
    Washington (the state)
    How often do they choreographed at your club? Mine only does once a year. I switched over to 9mm this year for IDPA to save a little money. I asked everyone what they shot with and loaded some of them up. Guess what that round didn't make PF. :whistling: So if I liked a round and it was border line I might just leave it there if I was using a lee disk. But if you get choreographed all the time it might be worth it to go up one size hole. did you raise the muzzle of the gun to move the powder charge to the rear of the case as suggested in the IDPA rule book?

    IDPA Rule book
     
  8. Wash-ar15

    Wash-ar15

    Messages:
    1,664
    Likes Received:
    0
    Joined:
    Sep 15, 2007
    I need something for the State Championship. They will Chrono for sure.

    I was looking at some other info sources. I may have gotten a slower lot of powder. My 3.7 gr load,which is commonly listed,seems to have no problem making PF according to what others have stated on the net.
     
  9. shotgunred

    shotgunred local trouble maker

    Messages:
    9,125
    Likes Received:
    1,401
    Joined:
    Mar 1, 2008
    Location:
    Washington (the state)
    Solo1000 is infamous for variations from lot to lot.
    Yes they will at renton.
     
  10. dsmw5142

    dsmw5142 NRA Member

    Messages:
    1,115
    Likes Received:
    0
    Joined:
    Oct 2, 2007
    Very true.

    Op, at the OAL your loading at I would bump it to 4.0gr and test 20 rnds. 10 for accuracy and 10 over the chrono watching for pressure signs.

    Personally I would keep the charge the same and shorten my oal down to around 1.125-1.120 and try that with another 20 as long as you have the chrono out. See which makes you happy.

    4.0gr of Solo with a 147gr bullet is alot of powder though and might be getting close to a compressed load, which isn't always a reason to not use it. Personally, I get the results I want with 3.5gr Solo and 147gr BBI.

    As already noted though, the lots of Solo vary widely at times. Make sure you start the process over again when you get a new jug.