.300wm load info?

Discussion in 'Reloading' started by Rem700addict, May 20, 2012.

  1. Rem700addict

    Rem700addict Well-Known Member

    Feb 19, 2012
    I'm just starting to reload for my .300wm right now I have some Rem brass and Hornady 180grn BTSP bullets. I was thinking about getting some IMR4350 or H4350. Would this be a good powder for this combo or is their better? I also have some 210 primers will these be hot enough? I'm new to reloading so any info would be great. These reloads will go in my Rem .300wm stock rifle.
  2. sticknstring

    sticknstring Well-Known Member

    Apr 28, 2011
    Don't overlook H-1000 for this weight and caliber. This is my to go to powder with my 300 wm/rem 700 and very happy with it .


    MTBULLET Well-Known Member

    Jul 16, 2007
    First, get a loading manuel or 2 and READ them. Will save you a lot of headaches in the future.
  4. jakes10mm

    jakes10mm Well-Known Member

    Nov 7, 2010
    I'm new to 300WM to and have tried a couple powders to date, including IMR4350 and RL22. I've shot primarily Hornady 180gr SST"s and Interlock SP's with a few Speer 180gr's thrown in. RL22 provided better velocities and great accuracy. I also bought the Brownell's sample packs for Berger 190gr and 210gr Hunting VLD bullets (12 ea). They posted good numbers across the chrono with RL22. I recently picked up some H1000 and ordered some Accubond 200gr bullets for more load development work. Will be ordering more Berger soon to test with H1000.

    RL22 - 180 SST - 3118 fps
    IMR4350 - 180 SST - 3033 fps
    RL22 - 190 VLD - 3072 fps
    RL22 - 210 VLD - 2931 fps
  5. grinnergetter

    grinnergetter Well-Known Member

    Nov 21, 2007
    X2....my factory Rem 300WM loves H1000
  6. reeldawg

    reeldawg Well-Known Member

    Mar 12, 2011
  7. Bart B

    Bart B Well-Known Member

    Dec 25, 2005
    When the .300 WM was popular for long range matches fired in the prone position. IMR4350 was the favorite for accuracy. And it worked fine with standard primers; magnum ones aren't needed unless you're after animals in sub freezing weather.

    While slower powders will usually shoot a given bullet out faster, those bullets won't land as close together on target as the medium-slow ones get such as IMR4350. Don't use any ball powder if best accuracy's your goal.

    I believe Sierra Bullets still uses IMR4350 in their .300 Win. Mag. cases testing 30 caliber bullets weighing 190 grains and heavier for accuracy as shot from super accurate rail guns.
  8. backwoods83

    backwoods83 Well-Known Member

    Jan 8, 2011
    Bart B wrote that well. Prep your cases as best you can, I do my hunting rounds same as match rounds. Fire your first load then just neck size until you need a slight shoulder bump, a 3 die redding set is fine, the type s bushing is better. I would start by jumping the hornadys about .060" with Imr or H 4350 with CCI BR2 or Fed210m primers, start around 68grns and work up. RE22 and 25 will give more velocity, but they are temp sensative and will give you higher extreme spreads and worse SD than the 4350s. H1000 is good in longer barrels, but the happy medium is H4831sc for speed and consistancy, on the low end I reccomend Federal match brass. With the vlds I reccomend seating them in the lands to start off.
  9. joe0121

    joe0121 Well-Known Member

    Jul 29, 2010
    This is what I use.

    208GR Amax
    79.5 Gr h1000
    CCI BR2 primers

    Win Brass primer pockets reamed and trimmed

    COAL 3.626

    .259 MOA

    Haven't chronod it yet but 79 GR got me knocking on 2900 FPS at 28 degrees ambient temp.
  10. Bart B

    Bart B Well-Known Member

    Dec 25, 2005
    Regarding how cases are managed for reloading them, consider what the track records been for the .300 Win. Mag.

    Best accuracy competitors got with the .300 WM and Sierra Bullets gets is with proper full length sized or brand new cases. Even the benchresters have been switching over to full length sizing their smaller cases for several years. Redding or RCBS full length bushing dies seem to be the best these days. And a collet die from Innovative Technologies helps a lot to keep that ridge right in front of the belt on fired cases eliminated; it's a known cause of poor accuracy. Use a case gage so you can measure sized case shoulder headspace then adjust the full length sizing die such that the fired case shoulder's set back no more than 2 thousandths; the resized case will then headspace on the chamber shoulder and that better aligns the case neck and bullet in then chamber as the case shoulder centers perfectly in the chamber shoulder when the firing pin drives the case hard forward.

    Years ago, it was quite a sight watching the military teams shooting either .30-.338 or .300 Win. Mag. brand new cases in 1000 yard matches and after winning them, giving away their once fired cases to civilians 'cause they didn't reload them. They tried conventional full length sizing (and even played with neck only sizing for some) but never got the accuracy new cases produced. Full length sizing dies don't get that tiny ridge in front of the belt sized back down to new case diameters and if that's not done, it interferec with repeatable case positioning in the chamber when the round's loaded. Larry Willis' collet die now solves that problem that used to be solved by cutting off the top and bottom of a standard full length sizing die then using that one to size fired belted case bodies al the way to the belt after a standard full length sizing die was used. I've done this with my 30 caliber magnums for long range matches and they shoot under 3/4 MOA at 1000 with both fired cases so sized and brand new cases.

    You don't need to prep cases other than turning their neck walls to less than a 1/1000th spread if they're worst than that when new.
  11. RTK

    RTK Well-Known Member

    May 9, 2012
    I never really thought about it that way. Thanks for the information, guess I will have to buy some new brass and a resizing die to try. Haven't yet shot any long range stuff, but I still like nice tight groups anyway