308 Load data questions

Discussion in 'Reloading' started by Erik the Red83, Mar 15, 2017.

  1. Erik the Red83

    Erik the Red83 Registered Member

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    I'm new to reloading and have not started just yet. I have a Remington R25 and Savage hog hunter, both 308 and 20in barrel with 1:10 twist. I have been researching plenty of load maps, powder brands, bullet brands, and primers. I have some questions that have been bugging me and I would like some advice from the experienced reloaders.
    Primer questions
    In the Speer manual #10 from 1979, they are using 165gr bullet and Winchester 748 with a magnum primer. Can I still use this data with large rifle primers instead? Is Winchester 748 a slow burning powder that needs/requires the extra ignition from a magnum primer? Is there an advantage to using magnum primers vs large rifle primers? Does the seating depth of a primer affect bullet accuracy?
    Case length question
    I have seen two case lengths, 2.005 and 2.008, which case length is generally ideal for 308?
    Powder brand question
    From your experience, is there a certain powder brand that you get the best performance with or have had the most success?
    Last two questions
    How can I tell if my rifles can handle compressed loads? Does having a muzzle brake have any affect on reloads?
     
  2. 613jmm

    613jmm U. S. Military Club Subscribed

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    I would research a more modern reloading source and make sure it matches up with the older data. Powder and primer formulations have changed over the years and that changes the loads published in books over time.

    A lot of people interchange magnum and non-magnum primer use. As long as you are starting low and working your way up, it rarely matters pressure wise. Most people will tell you it usually doesn't make a difference and they were forced to try the other when they couldn't find the specifically recommended primer. I don't use 748 so I can't answer the question directly, but you should be able to do an internet search for 748 and magnum primers and get a feel for others experience. I bet you find a lot of people that don't use them. Sometimes, the charge weight or the temperature might make it necessary to use magnums while other times it doesn't matter.

    I can't imagine how primer seating depth would affect bullet accuracy. There is one recommended seating depth. If you go too low, you are basically crushing the primer. If you don't go low enough, you can experience misfires because the first strike of the firing pin will finish seating it instead of igniting it.

    All of my loading manuals state 2.005 for trim length. I don't know why others would mention 2.008.

    Powder choice is very subjective based on availability, the firearms you use it in, your individual experience when working up loads, the type of shooting you will be doing, where you will doing your shooting, the bullet weights you are using, and a host of other factors. 10 people could say they use this powder, and it may not work for you.

    As long as your rifle is mechanically sound, and you are not going over published loads without some very careful inspection procedures, compressed loads should not be a problem. Compressed load does not necessarily mean you are in some kind of dangerous territory. It just means that particular powder has greater volume for a specific weight, so it is going to take up more space in the case. They are just telling you it is a compressed load so you can take precautions, such as using a drop tube for your powder funnel which helps get more powder in a case and prevents spilling powder, and so you don't freak out when you hear the powder crunching when you seat the bullet.

    Any kind of muzzle device can have an affect on any round. It doesn't matter if it is a reload. The affect is usually consistent and negligible.
     
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  3. Slacker

    Slacker Well-Known Member

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    First reply nails it.
    I PM'D you my number if you care to chat about the specifics of loading 308.
    The rabbit hole is deep, but depending on your needs, you may be able to keep it light.
     
  4. Howland

    Howland Member

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    Also to consider, are you looking for absolute optimum accuracy out of the bolt and absolute functional reliability out of the autoloader and want to use the same load in both rifles?

    If you don't want to segregate your ammo by which rifle it is for, you might have to decide which is most important in which rifle and is that acceptable for the other.

    You're in store for many range sessions. Enjoy!
     
  5. Erik the Red83

    Erik the Red83 Registered Member

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    Yes, I would like to use the same load in both but I know that bolt will always be more accurate than an autoloader and one powder brand might be liked better for one of the rifles vs the other one. I had not considered functional reliability until you mentioned it. But I have looked at Ramshot Tac and Accurate 2520 as options for the autoloader.
     
  6. timberman

    timberman Registered Member

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    My favorite powder for 308 is Varget. Been loading for that caliber for over 40 years and have never used a magnum primer. Maybe I missed something.
     
  7. Erik the Red83

    Erik the Red83 Registered Member

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    With all that experience I doubt you missed out, I'm sure you had the best that worked well for you and stuck with it. Did you ever notice if Varget was or is a dirty powder? Example, when you cleaned the gun did you notice more build up on the inner parts? Some have stated that IMR 4064 is a dirty powder based on other forums I have read.
     
  8. Howland

    Howland Member

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    With an autoloader, you will have to consider cartridge dimensions (full length sizing) and powder selection might be based on the gas system. If the R25 is strictly for punching holes in paper and the Savage is for hunting, bullet selection might make different loads readily visible. For bolt action rifles, I have always had excellent results neck-sizing only, then playing with OAL for the optimum "jump" to the lands. Then I determine how much charge is most accurate.

    Then if that load fits the R25 mags, functions and also has acceptable accuracy, you might be able to kill two birds with one stone.

    Might.

    Have fun, but be careful.
     
  9. Erik the Red83

    Erik the Red83 Registered Member

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    Yes, agreed, makes sense. Do you use a digital micrometer or non digital? Could either instrument potentially fail in its measuring ability and give you a false reading? And if a reloading table does not give minimum and maximum loads but just gives one grain weight like 42.2, what percentage should I start under? So if I go by 10% then would I start at 38 grains and work my way up by .2 or .5?
     
  10. Howland

    Howland Member

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    Either a digital or dial caliper can give reliable readings.

    Somewhere in the table it probably says something like, "Loads listed are maximum charges. Reduce maximum charge by XX% for a start charge."

    Your best investment will be the latest edition of a loading manual. I've used the Nosler manual only because I chose the Nosler Ballistic Tip for my hunting rounds. I was very pleased with both the bullets and the manual. It clearly states start charges and maximum charges.

    A good manual will point out little things like military cases often have a thicker case with the same exterior dimensions, meaning the case volume is less, meaning you can reach maximum (dangerous) pressure at a lower powder charge.

    Maximum charge is a certain pressure, not a weight in grains of powder. Learn what the signs of high pressure are and at the first sign, STOP, pull all bullets (buy a puller) and you now know what maximum charge is with that load. Any change in components, primer, bullet, case headstamp, etc., should be treated like developing a new load.

    I have always begun with the listed start charge and saw groups shrink as I increased the charge .5gr up to a point where the groups would open up. Then I would pull all remaining bullets and load several lots at .2 or .3 gr increments around that sweet spot to find the ideal charge. If you don't care about the difference between .7" or .9" groups, that may be a bit too analytical for you. That is the bane of my existence (and I am well aware that there is an abbreviated term for that affliction).

    This was true with every cartridge I loaded for (8). I never had any desire to find out what more powder would do after that. If I need more velocity, terminal performance, more anything, I took that as an omen that I would soon find a bigger gun in the safe.

    Did I already mention to learn what the signs of high pressure are?

    You will spend countless hours at the bench and then at the range. Range trips will cease to be plinking sessions and take on the seriousness of a scientific experiment. The end result will be the satisfaction of creating the most accurate load for your individual rifle at half the cost of the premium brands.
     
  11. dh2

    dh2 Registered Member

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    For starters I did check Hornady #10 manual and Nosler manual the latest version and they call for Fed. 210 and WLR primer no mention of the need for a magnum primer.
    I do not think that a new manual would be a bad investment
    W748 is a very good powder for the .308 Win. and is very temp stable which is good if you never know what of weather you will be hunting in.
    the .308 Win. has plenty of powders that it will take to very well to serval powders BL-C2 , IMR4064 and CFE223 for starters
    to me the .308 Win. is a good very basic round to learn to reload on.
    god luck and enjoy
    https://load-data.nosler.com/load-data/308-winchester/
     
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  12. timberman

    timberman Registered Member

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    I have not noticed Varget being that dirty. It may be worse than some but better than others. I like it because my Remington 700 VSSF and my Armalite AR10T like it. Other powders may work better in other rifles
     
  13. Slacker

    Slacker Well-Known Member

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    Most powders are "dirty" when loaded at the lower end. I would not let dirty/clean sway my choice of powder when it comes to 308.
    Pistol, yes, 5.56, perhaps, but not 308.
     
  14. mazer

    mazer Registered Member

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    Hmm....hitting both .308's head on! I like it! Well, I don't load .308 for any bolt guns, all Semi-autos for me! You need to do some research on the R25....that is not a rifle I'm familiar with. For most semi-auto "battle rifles" you'll find the max speed of the bullet is around 2400-2600fps and the heavier the bullet, the slower you will need to go. So, if you are going to use ONE recipe for BOTH types of rifle, be aware of the limitations! That said, I can get sub MOA out of my Galil and M1A loaded with a 168gr Hornady AMAX over 41.5gr's of H4895. Fortunately they BOTH like the same recipe!
    If you want to go faster with your bolt you'll need to keep them separate or chance breaking your R25.
    As far as primers go, well, some powders recommend magnum primers, they burn hotter than standards as a general rule, I use what the manuals recommend. You can always use the Winchester primers, they have some that can be used for powders that recommend magnum primers or not.
    Main thing to remember when reloading, it isn't rocket science, but you need MORE THAN ONE SOURCE OF RELOADING DATA! I always have at least three on hand...Lymans, Hornady's, and the Load Books, which are caliber specific. Bullet manufactures and powder manufacturers both have reloading data...so it's always good to know both especially if you are going to load at or near the max (like for hunting).
     
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