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Newbie Reloader Seeking Advise!

FEENIXFEENIX Member Posts: 10,558 ✭✭✭
I managed to do some loads and range time last weekend and yesterday.

RIFLE: SAKO M995 in .300WM, 23.5" barrel, 1:11 twist - all factory except for a custom muzzle brake by Joe Starnes, topped with 4.5-14x40 B&C Leupold scope, trigger set @ 2.5 lbs.

BRASS: Once fired Federal




(1) First load dev't, COL (3.34" base to tip not ogive) with the following powder capacity:

-68.5G, 69G, 69.5G, and 70G - none registered better than picture 1 [:(]

(2) Second load dev't, COL (3.62" - don't ask why . just wild guess . it clears mag and load fine) with the following powder capacity. Shots @ 100 yards.

Picture 1 - 70.5G

Picture 2 - 71G

Picture 3 - 71.5G

Note: No cleaning done for all 9 shots, approximately 3-5 minutes barrel cool off between shots.

There are no obvious signs of excessive pressure at this time. Do I press on up on powder? Do I keep the COL of 3.62"?

I appreciate any advise or insight that you might have. Thank you in advance for your support and understanding.




  • CapnMidnightCapnMidnight Member Posts: 8,520
    edited November -1
    I'd stop at 71.5grs, and keep the OAL. I haven't looked in the book, but you must be pretty close to max for a 200gr bullet, I've found over the years that I get best accuracy about 1gr below max on most rifles, your milage may vary. I load 75gr of H4831SC, Win WLR primer under a 180gr Nosler Partician or Accu-Bond. In a 24" barrel it shoots 1/2"-5/8" at 100yds. Kills elk quite well.
  • AmbroseAmbrose Member Posts: 2,943 ✭✭✭
    edited November -1
    Assuming WM stands for Winchester Magnum (and not Weatherby Magnum) my book says 71.5 gr. is a maximum load for that bullet. You are probably getting in the mid 2700's for velocity. I would stop there.

    PS: I think you're bragging--and you have a good reason to; with groups like those!

    EDIT: My remark about bragging WAS meant as a compliment--I'm glad you took it as one.
  • Rocky RaabRocky Raab Member Posts: 12,558 ✭✭✭✭
    edited November -1
    Don't change ANYTHING.
    I may be a bit crazy - but I didn't drive myself.
  • JustCJustC Member Posts: 16,049 ✭✭✭
    edited November -1
    run 5 shot group with 71gr and 71.5gr at 200yds. One will outshine the other.
  • FEENIXFEENIX Member Posts: 10,558 ✭✭✭
    edited November -1
    I was really hoping that someone will tell me to stop and that I have found the sweet load ... at least for me anyway. Thank you all for your response.


    You are correct, it is a win mag and so as the 71.5gr max for the bullet per Hogdgon reloading data center. However, my Nosler reloading guide 6th ed states that with H4831, max is 70.5gr but only @ 95% load capacity (I truly do not know what it means and I want to be on the safe side).

    Bragging? It was never my intention, but considering I can barely see the target and just my 2nd reloading test run, I'll humbly take that as a compliment. I am however having a blast in reloading![^] As I was warned, "it can be addicting". Absolutely true! I got so much to learn though!

    Thanks again for all your prompt response. Happy safe shooting/hunting.
  • nononsensenononsense Member Posts: 10,935 ✭✭✭✭
    edited November -1

    Congratulations on your very nice groups!

    From what you've told us, it appears that you have stumbled into a good, albeit low pressure, lower velocity load that is accurate. Let's clear up a couple of points though.

    There is a difference between a 'maximum load' and 'load capacity'.

    Maximum loads are based on the pressure generated by the components when fired. These are usually listed nowadays as PSI. In your particular situation, the .300 Win. Mag. has a pressure ceiling of 62,400 PSI rounded up slightly.

    Load capacity is the total amount of case capacity vs. the volume of the powder used in a particular load. Often, this is expressed as a percentage. Nosler's 95% is accurate when the OAL is left at 3.340" as per our books and references. That's the percentage of space that the powder is taking up in comparison to the total volume of the case with a bullet seated to that OAL.

    However, you seated your bullets out to 3.620" OAL which created more space in your case or increased the volume available. But you left the powder charge the same which results in a roughly 90% fill now. This also results in a lower pressure which is why you aren't seeing any signs of pressure.

    In most accuracy situations, reloaders attempt to get a balanced, accurate load which also fills the case as near to 100% as possible while still remaining in the same pressure zone. The reasoning has to do with powder position, consistency and repeatability. A full case doesn't let the powder shift around which could cause inconsistency. A partially full case lets the powder change position in the case and it might burn inconsistently shot to shot potentially resulting in less accuracy.

    Every powder/bullet combination has more than one accuracy node. You apparently found one at the lower end. If you continue to add a little more powder each time, the next groups may get a little bigger but with the continued addition of powder, they may then start to get a little smaller again. If you achieve the next accuracy node, you will have also gained velocity and more energy. This can be a benefit for those of us who hunt.

    I suggest pressing on to see what the outcome could be from more experimentation. If the groups remain small, do as JustC suggested and move back to 200 yards to shoot groups.

  • FEENIXFEENIX Member Posts: 10,558 ✭✭✭
    edited November -1

    Will do! Thank you for the clarification and enlightenment.

    Thank you all for your advise and encouragement.


  • chiefrchiefr Member Posts: 12,755 ✭✭✭✭
    edited November -1
    Agree with most and congrats; you developed a great load. Reloading provides superior accuracy. I too have had great results with 4831 & 4350 in the 300WinMag.
  • ArbyArby Member Posts: 668
    edited November -1
    FEENIX....I wouldn't touch a thing. Looking at the targets I would say that your 71.5 grains of 4831 is about as good as you are going to is what I would call a "tack hammer" recipe.

    Leave the C.O.L at 3.62" which would tend to have me believe that the free bore is about at optimum.

    You note that your brass was "once fired". If you only neck sized the brass before loading then the head space was probably optimum as well.

    In any case you really found the right recipe for your piece. Congratulations on the patterns ...#3s pattern does not usually come that is also politically sound being a little to the right of center....LOL
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