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  • byf43

    SCSC Life/NRA Patron Life
    Good morning, everyone.

    My youngest son just bought a Remington 700 "long range" in .300 WinMag.

    Just curious.

    Those of us that load for this, what is your favorite powder for this cartridge????

    I've seen some good references/reviews for H-4350 and IMR-4350, and also R-22 and R-25.
    W-760 gets some decent reviews, too.


    I'm researching all of these powders before I start loading for him.


    Thanks!
     

    Rockzilla

    Ultimate Member
    Feb 6, 2010
    4,516
    55.751244 / 37.618423
    Have used IMR4350 with 168gr Bergers,175gr Bergers,and 210gr Bergers all with good
    results in a Rem 700 action, Hart Barrel, (in which some day will be replaced with a Bartlein),
    but switched to 7828, H1000 as that is what the .338 Lapua uses, the later works good
    with the .300 WM. have fun it's a nice all around caliber to load for, a very large variety
    of bullets and weights to choose from.

    -Rock
     

    Rockzilla

    Ultimate Member
    Feb 6, 2010
    4,516
    55.751244 / 37.618423
    Thanks, Rock!

    Saw some data on the H1000, last night.[/QUOTE

    If I may what bullets are you planning on using?

    Berger lists:
    78.5gr-83.0gr with a 104% fill ratio in 168gr
    78.0gr-82.0gr with a 103% fill ratio in 175gr
    71.5gr-75.5gr with a 102% fill ratio in 210gr
    COAL: 3.340"

    Don't have my load book handy and don't remember off hand.
    will see if I can dig up the load data for 4350 also.

    I just tried to cut down on all the different powders (clutter)
    and if you need some nfo got the Berger, Hornady X, Lyman 50th, Sierra manuals,
    can't wait for the new Sierra one to come out next year (they just were acquired
    by Clarus Corporation)

    -Rock
     

    BUFF7MM

    ☠Buff➐㎣☠
    Mar 4, 2009
    13,576
    Garrett County
    I'll have to look this weekend when I get home, but if my brain cells are in gear I'm running 180 grain pills over IMR 4350 But let me look tomorrow.
     

    85MikeTPI

    Ultimate Member
    Jul 19, 2014
    2,699
    Ceciltucky
    Mine is IMR 4831. Tested with 168gr SMK, 175gr SMK, 190gr SMK, and 220gr SMK. My rifle definitely likes the 190s best in the 600-1000yd range.
     

    Topher

    Ultimate Member
    MDS Supporter
    Sep 8, 2008
    4,817
    Fredneck
    I have had experience and done some reading... The IMR powders are more temperature sensitive and do not like the warmer weather. Anyone else have that issue?

    As a result I have gone with the H over IMR version of the powder.
     

    byf43

    SCSC Life/NRA Patron Life
    If I may what bullets are you planning on using?

    Berger lists:
    78.5gr-83.0gr with a 104% fill ratio in 168gr
    78.0gr-82.0gr with a 103% fill ratio in 175gr
    71.5gr-75.5gr with a 102% fill ratio in 210gr
    COAL: 3.340"

    Don't have my load book handy and don't remember off hand.
    will see if I can dig up the load data for 4350 also.

    I just tried to cut down on all the different powders (clutter)
    and if you need some nfo got the Berger, Hornady X, Lyman 50th, Sierra manuals,
    can't wait for the new Sierra one to come out next year (they just were acquired
    by Clarus Corporation)

    -Rock

    Right now, I've got some Hornady 165 gr, Sierra 165 and 168 grain.

    I'm picking his brain, trying to find out IF he's just going to be punching paper, or if he's going to use it for hunting.

    Right now, nothing is 'off the table'.
     

    byf43

    SCSC Life/NRA Patron Life
    I'll have to look this weekend when I get home, but if my brain cells are in gear I'm running 180 grain pills over IMR 4350 But let me look tomorrow.

    Thanks, Buff. Look forward to reading what you're using. :thumbsup:

    Mine is IMR 4831. Tested with 168gr SMK, 175gr SMK, 190gr SMK, and 220gr SMK. My rifle definitely likes the 190s best in the 600-1000yd range.

    Thanks, Mike!
    Looks like we'll be doing some testing, pretty soon.

    I have had experience and done some reading... The IMR powders are more temperature sensitive and do not like the warmer weather. Anyone else have that issue?

    As a result I have gone with the H over IMR version of the powder.

    I've not used very many IMR powders.
    I am pretty fond of the H- powders.

    Thanks!
     

    PowPow

    Where's the beef?
    Nov 22, 2012
    4,712
    Howard County
    I have had experience and done some reading... The IMR powders are more temperature sensitive and do not like the warmer weather. Anyone else have that issue?

    As a result I have gone with the H over IMR version of the powder.

    IMR's Enduron powders address the temperature sensitivity and have improved burn consistency. All 4 Endurons (4166, 4451, 4955 & 7977) have load data for .300 Win Mag depending on what you're looking for.

    https://imrpowder.com/imr-enduron-4166/

    https://imrpowder.com/imr-enduron-4451/

    https://imrpowder.com/imr-enduron-4955/

    https://imrpowder.com/imr-enduron-7977/
     

    BUFF7MM

    ☠Buff➐㎣☠
    Mar 4, 2009
    13,576
    Garrett County
    Follow up post:
    From my reloading log I've got IMR 4350, my best groups were from 67 grains (sub 1" groups/5 shots). These were pushing 180 grain Sierra Spitzer #2150's. Winchester large magnum rifle primers, Federal brass. Cases trimmed to 2.62, with a COAL of 3.34
     

    dist1646

    Ultimate Member
    May 1, 2012
    8,760
    Eldersburg
    Subscribed. I have a 700 long range in 300 win. mag. that I have not shot much. Only 30 rounds of factory ammo so far. I have actually been considering selling it since I don't really shoot it. I think I read somewhere that the Army chose RE-22 for their 300 win. mag. ammo.

    Correction, the specified powder for the MK248 Mod.1 ammo is H1000 with a 220gr Sierra.
     
    Last edited:

    byf43

    SCSC Life/NRA Patron Life
    IMR's Enduron powders address the temperature sensitivity and have improved burn consistency. All 4 Endurons (4166, 4451, 4955 & 7977) have load data for .300 Win Mag depending on what you're looking for.

    https://imrpowder.com/imr-enduron-4166/

    https://imrpowder.com/imr-enduron-4451/

    https://imrpowder.com/imr-enduron-4955/

    https://imrpowder.com/imr-enduron-7977/


    Thanks. I'll do some reading on these powders tomorrow.



    Follow up post:
    From my reloading log I've got IMR 4350, my best groups were from 67 grains (sub 1" groups/5 shots). These were pushing 180 grain Sierra Spitzer #2150's. Winchester large magnum rifle primers, Federal brass. Cases trimmed to 2.62, with a COAL of 3.34

    Thanks, Buff!!!!!!






    Subscribed. I have a 700 long range in 300 win. mag. that I have not shot much. Only 30 rounds of factory ammo so far. I have actually been considering selling it since I don't really shoot it. I think I read somewhere that the Army chose RE-22 for their 300 win. mag. ammo.


    IF you're lookin' to sell................ shoot me a PM.
    Both Bass Pro and Cabela's have it on sale, right now. (Even though my son got the last one that was at BP, last week.)
     

    Rockzilla

    Ultimate Member
    Feb 6, 2010
    4,516
    55.751244 / 37.618423
    Got some loading data for IMR-4350
    All CCI primers WW brass
    Sierra 168 HPBT 71.6grs. COAL: 3.345
    Sierra 190 HPBT 67.2grs. COAL: 3.345
    Sierra 220 HPBT 63.1grs. COAL: 3.345
    these are the sweet spot loads for the rifle
    I have.

    a read here on it:
    http://www.65grendel.com/forum/archive/index.php/t-8586.html

    and a pdf of the mil data for it

    http://usarmorment.com/pdf/300WM_load data.pdf


    as far as Temp issues noticed none in the Enduron powders.
    same can be said with 8208 use it in the 5.56 and 7.62 switched
    from Varget, it meters well.

    -Rock
     
    Last edited:

    BUFF7MM

    ☠Buff➐㎣☠
    Mar 4, 2009
    13,576
    Garrett County
    Got some loading data for 4350
    All CCI primers WW brass
    Sierra 168 HPBT 71.6grs. COAL: 3.345
    Sierra 190 HPBT 67.2grs. COAL: 3.345
    Sierra 220 HPBT 63.1grs. COAL: 3.345
    these are the sweet spot loads for the rifle
    I have.

    a read here on it:
    http://www.65grendel.com/forum/archive/index.php/t-8586.html

    and a pdf of the mil data for it

    http://usarmorment.com/pdf/300WM_load data.pdf


    as far as Temp issues noticed none in the Enduron powders.
    same can be said with 8208 use it in the 5.56 and 7.62 switched
    from Varget, it meters well.

    -Rock

    Is your data for H or IMR? I'm just curious as to looking at the sweet spot for the 190 grain load.
     

    Rockzilla

    Ultimate Member
    Feb 6, 2010
    4,516
    55.751244 / 37.618423
    No problem I was curious as to which. I probably should have added my rifle to my post. savage 111.

    yeah.. I here ya, that's why I say 700 action, then barrel make.
    the 190gr load shoots great don't have the detailed information
    I normally put it all together, didn't chrono it either (yet) and
    I know sometimes looking at the primer will tell you some things,
    no visual signs of pressure issues.
    Anyway it should give you some kind of "ball park" idea, used the
    OCW method, start lower in charge, one other thing I do is make
    a dummy round so I get an idea of what the total OAL can be, it
    may not fit the magazine, but...

    -Rock
     

    10xclean

    Active Member
    MDS Supporter
    Dec 23, 2008
    358
    Kingsville
    7828 was my best powder after trying R22, r25, H1000, and both 4350. Got 1/2" groups with the 7828 in a Rem 700 PSS in 300 win mag. Using 175's and 190's.
     

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