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308 velocity dilemma

Discussion in 'Handloading and Reloading' started by CaneCorso85, Oct 22, 2011.

  1. CaneCorso85

    CaneCorso85 Active Member

    Hey guys,

    I'm having a bit of trouble getting my 308 ammunition to register anywhere near the load data velocity using the prescribed loads. Here's what i'm using:

    Lake City brass
    168 SMK
    Win LR Primers
    Fired from an M1A Socom
    Data from the Sierra and Lee manuals

    The data in the lee manual calls for a starting load of 41gr of H4895 (they don't list data for IMR) working up to 43.5gr, which should produce 2703 fps.

    The Sierra manual calls for 42.1gr of IMR4895 to only get to 2600fps (does not list data beyond that speed)

    Here's what I loaded, and the speeds it chrono'd at:

    (yes, I started lower previously and the speeds were in the 2300's)

    #1 - 2415fps
    #2 - 2487fps

    #1 - 2525fps
    #2 - 2539fps
    (note I'm now exceeding data from both books and still not even close to the listed velocities. No signs of overpressure on the casings)

    #1 - 2534fps
    #2 - 2530fps
    #3 - 2544fps

    #1 - 2614fps

    My target velocity is 2660

    Question is, despite being pretty high above the max loads for each manual, I'm still not at the prescribed velocities; should I go to 27gr to try to hit 2660? I can take some pictures of the brass for each load if that would help, however, I had a couple of experienced reloaders take a look at them and they didn't see any signs of overpressure. I don't imagine Sierra and Lee got that data using a gas operated rifle like the M1A. It's probably safe to assume a lot of that pressure is lost operating the action, which would tell me I'm probably safe to keep going. I'm just curious what the experts at THR have to say about it.

    BADUNAME37 Well-Known Member

    The more relevant question would be "at which load are you pulling the tightest groups?"

    Raw power is not everything. As a rifleman, you are going to learn to make each shot count, right?

    If a well-placed shot is made and the bullet is going 200 fps slower than a lousy-shot into the gut, the well-placed shot will be the one with the meat on the table EVERY TIME -- whereas the lousy gut-shot will be the one where the animal suffers, only to be found by some pack of coyotes. Besides, dead is dead, the animal shot is not going to know that the bullet happened to be traveling 200 fps slower than some other loads DESIGNED FOR OTHER GUNS!

    I have one load that is borderline maximum (some slight signs of overpressure), and the ONLY REASON I stuck with that particular load was because -- out of about 21 loads I tested, that load pulled, by far the most accurate and tightest group! The gun is a bolt action with 22" barrel! Had the less-powerful load been more accurate, that is what I would have gone with. I don't want to prematurely wear out my chamber and barrel. As it is, with that particular rifle, I shoot only when I know I am going to hit something. I know where it shoots, I know it is accurate, there is no need at all to shoot up bottles, rocks, cans, and go plinking with it. Unlike your gun, mine is not a gas-operated gun!

    When you begin pushing pressures in a gas-operated rifle, the timing ends up being 'off' which will rapidly wear parts and may eventually result in a 'kaboom-situation' which we, as reloaders, strive to never have happen!
    Last edited: Oct 26, 2011
  3. rcmodel

    rcmodel Member in memoriam

    M1A Socom huh.
    Thats the one with the 16" barrel right?

    That right there is your problem!

    You will never reach load book velocity safely with a chopped off barrel like that.
    So, don't even try it.

  4. Grumulkin

    Grumulkin Well-Known Member

    Yes, M!A SOCUM? Do you have any idea of what high pressure signs are in a semiauto?

    You better quit chasing velocity before you wreck your gun.
  5. rcmodel

    rcmodel Member in memoriam

    You can safely assume NO pressure is lost in the action.

    The bullet is long gone before any gas goes to the gas piston and starts the action operation.

    You need to Cease & Desist Immediately, if not sooner.
    By your own admission, you are already 5.0 grains over max, likely using Bolt-Action data.
    Referancing H-4895 instead of the IMR-4895 you are using!!
    And you are considering going higher yet in a gas gun!!

    Mercy, mercy, mercy!!

  6. Casefull

    Casefull Well-Known Member

    Short barrel, get some faster powder...I seriously doubt you are going to blow up the rifle.
  7. Ridgerunner665

    Ridgerunner665 Well-Known Member

    WRONG...on both counts!

    Faster powder won't help...I know because I've been down that road. And he will most certainly wreck that gun if he hasn't already.

    You need to be using "service rifle data" in that rifle...and with IMR 4895 the max load with 168 grain bullets is 41.4 grains...going higher MAY NOT explode the rifle, but it WILL damage it if it hasn't already. Get some Varget powder, it will likely get you all the velocity that you're gonna get..which will be around 2,300-2,400 fps.

    Thats what short barrels do...they cost velocity.

    Please...be safe!

    2,660 fps...thats hard to achieve even with a 20 inch barrel on a bolt gun. (For the record...that Sierra manual you have used a 26" barreled Savage as the test rifle)

    Also, you could use lighter bullets...150 grains.
    Last edited: Oct 22, 2011
  8. Ridgerunner665

    Ridgerunner665 Well-Known Member

    IMR 4895 and H 4895 are not the same powder...IMR is a faster burning powder, and its a temperature sensitive powder. That means it burns a lot hotter in warmer ambient temperatures.

    H 4895 is very temp stable, as is Varget...ambient temperature does not affect it.

    You are playing fire...make no mistake...STOP, research what the folks here have said and you will see.
  9. wanderinwalker

    wanderinwalker Well-Known Member

    Isn't this the second time in the last few week's we've had somebody trying to get full-length velocity from a carbine barrel? :uhoh:

    To the OP, STOP! CEASE AND DESIST! You're well into no-man's land already. You have a 16" barreled semi-auto and you're trying to get the speeds the .308 generates from a 22" barrel. Ain't going to happen. Your SOCOM is going to run about 200-fps under any book load you find. Be happy with about 2400-fps with a 165/168. You could get a bit more speed with a 150, but I'd doubt you will see much more than 2550 or so even then.
  10. gamestalker

    gamestalker member

    If it were me I would switch to a slower buning powder, you'll get the velocity and acuracy is generally excellent with them. Check out loads with RL17 or better yet RL19 and velocity will certainly improve.
  11. Grumulkin

    Grumulkin Well-Known Member

    Just curious. Have you ever loaded for an M1 or an M1A? Do you know what slower powders can do to the OP rod?
  12. amlevin

    amlevin Well-Known Member

    I used to "chase velocity", using just about every powder and load for my .308that was ever recommended.

    Then one day, by accident, I found that the most accurate load was one of the slower loads published. It isn't what the "book" or "chronograph" says, it's what shows up on your target at the desired range that matters.

    If you haven't achieved desired results by the time you reach "MAX LOAD", it's time to stop and reevaluate.
  13. gamestalker

    gamestalker member

    Grumulkin, I haven't loaded for one of those bugger's in 25 or so years, so I don't really recall what they like to eat. I was just trying to help what sounded like a plea for velocity.
  14. CaneCorso85

    CaneCorso85 Active Member

    For those suggesting Varget and slower powders; Every piece of material I have read about reloading for the M1A/M14 platform states that Varget (or powders of equivalent speeds) are too slow for the gas system.

    For everyone else; Message received. The good news is that the rounds in the data I posted are the only excessive loads ever put through the rifle. The only reasons I loaded those, was because I got the ominus dominus from an experienced reloader and m14 armorer. He has, however, never owned a 16" barrel for one and that may be the disconnect.

    I'm focused on velocity because I'm trying to load for long ranges (600 w/168 and 1000 w/175). I'm starting to accept that the SOCOM is limited by quite a few factors, but it's what I have to start with so I'm trying to get as much out of it as I can. I have no doubt I can load something accurate at 200 yards, but that wasn't the goal. I guess I should have stated that in the original post.

    Thanks for the advice guys.
  15. You-Two

    You-Two Active Member


    I would recommend reading Zediker's article on loading for M14s located here. While a bit conservative, he highlights the unique aspects of reloading for an M14 type rifle. You can't get as creative with this beast as you can with a bolt gun. Seems like the "standard" loads for highpower are around 40.0-41.5gr using a 4895 type powder...with 40.5gr being "the" load. Winchester commercial cases are also preferred for the long-range events since they generally have more case capacity. I would stay away from any mil cases as they have less capacity...which means higher pressures with the same load.

    Good luck with your pursuit!
    Last edited: Oct 23, 2011
  16. Ridgerunner665

    Ridgerunner665 Well-Known Member

    There are some folks that say Varget (or Reloder 15) is too slow for an M1 type rifle...but there are also a lot of folks who say that its fine...its one of those things that some folks like to debate...

    All I can offer is this...I have shot a few thousand rounds using Varget and Reloder 15 in an M1a, and my rifle is still going strong, no problems whatsoever...very accurate too.

    By the way...if you can get a 168 grain bullet (or even a 150-155) up to 2,300-2,400 fps it will perform just fine at 600 yards. It will have a bit more drop but it will be just as accurate as ever. And forget about 175 grain bullets if that rifle has a 1 in 12" twist...you'll never get them fast enough to remain stabilized.
  17. oldpapps

    oldpapps Well-Known Member

    CaneCorso85, I believe that you have proven how strong the M1A action really is.
    My Lee manual doesn't list what barrel length was used in their testing, I don't have Serra book handy, so that's a no help. However my old Speer book shows there tests in a 22 inch barrel. I think it would be a safe guess that most if not all manuals test with barreled actions that are on the long side of what is carried in the field.

    To the point:
    I would not hope to expect to equal the listed velocities with a shorter barrel.
    Using H4895 data but using IMR4895 powder is not safe! They are two different powders.
    If your only goal is to shoot a faster bullet, get a 220 Swift or something like that.
    To equal or exceed book velocities, get a 28 inch barrel for a Thompson take down action and then slowly work up with the correct components.

    Oh, could you provide some photos of the brass that you fired with these loads? I would like to see the primers and head expansion.

    Remember, no one wants you to be hurt. So only error on the side of safety.

    Last edited: Oct 23, 2011
  18. zeke

    zeke Well-Known Member

    2400 fps is about tops in what to expect using a 168 gn bullet in 16 in barrel 308. 2600 fps with 150/147 grainer.
  19. JohnKSa

    JohnKSa Well-Known Member

    "max" is short for "maximum".

    Maximum means:

    a. The greatest possible quantity or degree.
    b. The greatest quantity or degree reached or recorded; the upper limit of variation.
    c. The time or period during which the highest point or degree is attained.
    2. An upper limit permitted by law or other authority.
    3. Astronomy
    a. The moment when a variable star is most brilliant.
    b. The magnitude of the star at such a moment.
    4. Mathematics
    a. The greatest value assumed by a function over a given interval.
    b. The largest number in a set.
    1. Having or being the greatest quantity or the highest degree that has been or can be attained: maximum temperature.
    2. Of, relating to, or making up a maximum: a maximum number in a series.


    Notice that every definition and meaning of maximum implies that nothing exceeds the maximum.
    Both of those are incorrect assumptions and also unsafe.
    Buy another reloading manual or 2 or 3 and use them to verify any data provided by "experienced reloaders".
    Reloading not a productive or safe activity for people who don't follow rules.

    You can be thankful that you didn't blow up your rifle and harm yourself or others.
    Last edited: Oct 23, 2011
  20. USSR

    USSR Well-Known Member


    You trying to blow your rifle up? The loads you listed using more than 43 grains of IMR4895 with Lake City brass are dangerous high pressure loads. I guarantee the load data you are using does not use Lake City brass. You cannot take .308 load data using commercial brass, and transfer it to 7.62x51 brass without reducing the charge weight. Adding more powder to reach a certain velocity without taking the pressure generated into account is an accident waiting to happen.


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