Load Developement ???

Discussion in 'Long Range Hunting & Shooting' started by Iowaboy, Dec 21, 2009.

  1. Iowaboy

    Iowaboy Well-Known Member

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    So I have a question for you experts out there.

    I have a Savage 7mm rem mag with 26 inch McGowen barrel, heavy duty SSS recoil lug, the 1.5 lbs trigger spring installed and a Stockade elk tracker stock. On top sits a NF 5-22 NXS in NF rings and one pieve base.

    So I am trying to find the most accurate load using 168grain bergers. I'm trying reloader 25 and h-1000 for powders. Starting at low to high amounts of powder in .5 incriments. This weekend I was shooting 3 shot groups at 225 yards. I figured the longer range verses the 100 yards to show me a little better which poweder amounts work better.

    It was 30 degrees with a little wind varing probably 3-7mph. So I was getting a lot of groups that would print two shots within a half inch or each other and the other was and inch lower. Now this lower hole was not usually the third shot most of the time it was the second one.

    Any ideas on that? It that normal when load developing. I did end up with a load wth each powder that put all three with in an inch and a quarter. Making them just over 1/2 moa as I was shooting at 225 yards.

    Also this is a freshly broke in barrel, you know the 10 shots cleaning in between, then ten more cleaning every other shot.

    When shooting I cleaned the barrel inbetween the two different brand of powder about 25 rounds each. And I alowed some time beween 3 shto groups so that the barrel never did get more than barely warm enough to tell it wasn't completely cold.

    So my question is that normal and so I just go with the two best loads and work .2 grain incriments up and down to see if either will do better, then start into bullet seating depth changes.
     
  2. trueblue

    trueblue Well-Known Member

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    Have you determined where you start to get pressure issues, and are loading on or off the lands ?
    The first thing I do before load developement is seat on the lands, and go up in charge weight until I know where my top end isfor pressure. Then I know where to go from there.
    Your 1" of verticle could be associated with less velocity. Do you have a chronograph to shoot over to see what your ES is?
    I would try one powder at a time, and not clean the barrel once you start load work for at least 30-40 rounds. I would also look at Retumbo, as I am pretty sure it will be a better powder for you in the 7 RM.
    Start out at 70, work you way up to 74gr.
     

  3. squirrelduster

    squirrelduster Well-Known Member

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    Blue is right about not cleaning.
    What exactly is your load workup routine?
    I think you can do better than the inch and a quarter you are shooting.
    Give us some details.
     
  4. Iowaboy

    Iowaboy Well-Known Member

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    So I started out by coming here and found on a old thread that someone had posted load recomendations from Berger for various different powders.

    Then I loading one bullet at the lands (measured with Hornady OAL gauge) each in .5 grain increments from 66-70 grains of H-1000, and 64.5-68 grains of Reloader-25.

    Never did see any signs of pressure, like loose primers or hard bolt lift. What else should I be looking for? Also its kinda cold around these parts this time of year how far should I push it trying to find my upper limit of pressure?

    Then I loaded up 3 bullets of each amount of powder for both types of powder and shot them at the 225 yard range. As a matter of fact my best group with Re-25 was the 68 grain load.

    I do have access to a chrony, but from some of the reading I've done on here I didn't know if they are to be trusted anyway. Plus this last weekend when I got a chance to shoot the chrony was at my Dads and thats a 4 hour round trip. I'll pick it up this weekend for my next range day.

    Should I try moving up some more in charge weight till I get pressure issues before I start messing with oal some?
     
  5. trueblue

    trueblue Well-Known Member

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    At this point, I would stick with the H1000 or try some Retumbo. They are more temp stable powders than R-25
    I do think it is important to find your upper limit of pressure. Keep the ammo warm in your car if you are concerned about a pressure spike in warmer weather.
    Since you have already done some load work, it shouldn't take to much more work to find your upper pressures.
    After that back off on charge weight alittle and try some groups. Then try some loaded at different distances off the lands, and into the lands no more than .005 if this is a hunting rifle. Say on lands, 0.020/0.050/0.070
    See what groups best for you. Or, load different charge weights, but all at the same distance from the lands, and see what groups best for you. But only change one factor at a time.
    The reason I use a chrono when load developing is to see at what point I don't see anymore velocity with more powder. There is no sense in loading more powder if you don't get much return for it. The other reason is to see what my ES is.
    I need a low ES for tighter vertical at longer distances.
    I would be looking for 1" groups at 200yds.
    Also, if you are shooting in the snow, on the ground, that is more difficult than on a nice summer day, so your groups might not be as tight.
    If you are happy with what you have when you posted, find a place to shoot at 300 to see what your groups are like.
     
  6. Iowaboy

    Iowaboy Well-Known Member

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    I think I'm going to get the chrony before I shoot again. And maybe work up in charge wieght a little more to see what I gain if any. Then try moving back off the lands and see where that takes me.

    Thinking about it when I was shooting this weekend I did have some wind so maybe a couple of my groups could have been better. As per the ballistic program at 225 yards 10mph wind could blow me off as much as 2.5 inches. Seeing that I had all my groups under 2.5 inches I hope I was close enough on my best groups to have one to go with!
     
  7. squirrelduster

    squirrelduster Well-Known Member

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    Are your groups horizontal or vertical?
    If vertical you have load issues, horizontal it could be wind or shooting form. I had horizontal groups on my 300 win mag and it turned out to be me gripping too tight.

    Work on the powder charge first and when you have everything as good as it gets then work on the seating depth.

    For your powder charge I would do a ladder test with the powder you are currently using. Do a search on here or 6mmbr.com for instructions. Stay away from the R25 as blue said it is temperature sensitive.

    An short instruction for a ladder test.
    Load up a series that has the powder charge go up by .4 grains at a time and shoot them at 1 small target at 225 yards. You will see a cluster of three or so loads that will probably be better than than what you are now shooting. Pick the middle one and then do your seating depth testing.

    Here are the instructions from the Berger website,
    For years we have relayed that it is best to jam the VLD into the lands for best performance. This works for many rifles however there are many rifles that do not shoot the VLD well when the bullet is jammed. We have learned that the VLD can shoot best as much as .150 jump off the rifling. VLD bullets can be sensitive to seating depth and it has been found that these bullets shoot best in a COAL “sweet spot”. This sweet spot is a COAL range that is usually .030 to .040 wide.

    The quickest way to find this sweet spot is to load ammo at four different COAL. Start with a COAL that allows the bullet to touch the rifling. The next COAL needs to be .040 off the lands. The third COAL needs to be .080 off the lands. The last COAL needs to be .120 off the lands. One of these COAL will outperform the other three by a considerable margin. It has been reported that the VLD bullets don’t group as well at 100 yards but get better as the bullet “goes to sleep” at further ranges. We have learned that by doing the four COAL test you will find a COAL where the VLD bullets will group well at 100 yards. Once the COAL that shoots best is established you can tweak +/- .005 or .010 to increase precision or you can adjust powder charges and other load variables. Frankly, those who do the four COAL test usually are happy with the results they get from this test alone.


    Keep us posted on your progress. The chronograph is a great tool to tell you extreme spread that will equal vertical spread at long range.
     
  8. Iowaboy

    Iowaboy Well-Known Member

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    I did have a couple groups that were awsome verticle spread (like less than .5 inch, but spread out horizontal almost 2 inches.

    I probably just need to pick a better day with no or very little wind and really watch my form.

    I was thinking that the Re-25 would be a good one because it book lists higher velocity, but I did notice that it sounds different. Its more like a pop than a bang and made me think something was wrong, but they all did that with the re-25.

    Might have to try out Retumbo next. Ganna have to get me some more bergers I can tell you that already!
     
  9. squirrelduster

    squirrelduster Well-Known Member

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    Don't switch!
    Use one powder until you find it doesn't work. The gain in velocity of one powder or another is not worth the effort to change.
    If you are getting very little vertical with that one load I would bet it has more to do with form than wind unless you have a lot of wind.
    The problems than I have had with form were unbelievable. I found out after I fixed my form that the load I couldn't get to shoot before would do under 1/2" at 100 yards with one of the better groups at .381. Not bad for a sporter weight 300 win mag.
    My biggest problem is being patient enough to do one thing at a time.
     
  10. statjunk

    statjunk Well-Known Member

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    Why is it so important that you find the max pressure?

    Tom
     
  11. Harry

    Harry Member

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    If your having trouble holding the rifle still I would invest in a leadsled, that way it takes all the human arror out of it. I use one on all loads I work up that way I know it wasn't me that made it go wrong.
    I have found that the H 1000 works best in the two differant rifles that I load for. One is shooting a 160 Sierra BT and the other is shooting 160 gr. Nosler Accubond. So it all depends on the rifle as to what it likes the best.
     
  12. statjunk

    statjunk Well-Known Member

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    Lead sleds can change POI. I've witnessed this myself. I think it's the harmonics. Otherwise I have no idea.

    Tom
     
  13. Harry

    Harry Member

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    I have found if you don't get the eye inline with the scope it will change.
    It is differant when you look through the scope while it is on the lead sled that is why you need to be careful when looking through the scope and make sure you are lined up.
    Just like one note someone else said in this fourm it is just like when you are a passenger and looking at the speedometer and it looks like you are going a differant speed then you are.