How do you "dial in" a load?

Discussion in 'Ammunition & Reloading' started by Shopfox, Sep 10, 2017.

  1. Shopfox

    Shopfox Well-Known Member Supporter

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  2. Dallas53

    Dallas53 Well-Known Member Supporter

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  3. hairbear1

    hairbear1 Well-Known Member

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    On the subject of primers improving groups I'm very sceptical of this because over the years I've used whatever primer I could at times when I couldn't get what I usually use and never once did the groups improve or worsen with different brand primers so I'm not convinced that this is a tuning tool especially how as neck tension, seating depth, powder and powder weight and projectile selection do more than primers do.

    The only time I've seen primers do some real good is the use of magnum primers in the bigger calibres and powder weights (big .30s and up)for better ignition.
     
  4. Shopfox

    Shopfox Well-Known Member Supporter

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    Take this with a grain of salt: the Lee reloading book talked about different manufacturers using a different compound for their primers. There are 2 different types of compounds used one is more explosive/volatile than the other. CCI and Remington were the more stable compound, Winchester was more volatile. Because of the differences, Lee stressed loading no more than 10 Winchester primers in their priming tool, whereas no problems with 100 CCI or Remingtons.

    With all this said, Sierra had an article comparing carefully prepped cases (deburr flashhole, uniform trim length, uniformed pockets, etc.) vs. Non-prepped cases. The difference was akin to 0.1 inches (2.54mm).

    My gut feeling (no data) is primer influence is on the same magnitude or less than the 0.1 inch. An influence, but not the difference in poor and great groups.
     
  5. Dallas53

    Dallas53 Well-Known Member Supporter

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    normally, i would think a primer, is a primer, is a primer!

    but given the who the guy is that wrote the article, i would give it some credence and think it bears looking into.

    now the cost of primers is negligible among most brands, and a person that is reloading, is going to buy primers anyways, so it couldn't hurt to try different brands of primers to see if they work better with different brands or types of powders in the loads.
     
  6. Shopfox

    Shopfox Well-Known Member Supporter

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    I think I may switch to just 3-shot groups when doing the ladder test, and then do the tighter 0.2 to 0.3 interval. If there's a poor group at 3-shots, 5-shots won't improve it. I'm coming to appreciate how sensitive ammo loads are, and the influence of very small changes.

    I used to think the chrono was primarily for verifying velocity for long-distance shooting. I didn't see much use otherwise (I figured, if velocity is consistent, groups will be consistent). What I failed to appreciate was the chrono data may show a really consistant set of velocity for 5-shots. If my target has 4 tightly clustered shots, and a flier that opens things up - it raises a flag that shooter error may be a factor with that "flier". I also hadn't even thought or considered using a chronograph to do a ladder test, and making a velocity table/graph to look for sweet spots.

    A lot of good eye-opening insights! Thanks!
     
  7. Txhillbilly

    Txhillbilly Well-Known Member

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    I've tried primer testing a few times with 223 cartridges. I used several different brands of standard, magnum, and benchrest primers. My groups didn't vary much, only had minimal velocity changes. IMO, it was a waste of time.
     
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  8. Shopfox

    Shopfox Well-Known Member Supporter

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    Talked to a tech at Sierra. Load data is completed at Sierra, and is on its way to me.

    There's an updated manual coming out late next year, and the 6.8 SPC will be included.
     
  9. Shopfox

    Shopfox Well-Known Member Supporter

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    Great info from Sierra. I'm going back to the drawing board, and will do a new ladder test with their cartridge length and loads. It matches very, very closely with the Lee data. Both are higher powder charges and shorter length OAL's than I've used till now. Basically, I haven't even worked my way up to their START loads yet.
     
  10. dwmiller

    dwmiller Well-Known Member

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    Only time it seems to make much difference for me is the dead of winter. Then I go to a magnum primed load to regain some of the velocity I lost to the cold. Magnums below 0deg make a 2-300 fps difference across the chronograph, 308's 300 magnums, compared to standard primers. In warm weather they show almost no difference.

    I use magnums for my deep winter hunting loads. Makes a difference in elk or antelope hunts. Not so much on 223 when I tested ~100 fps was the biggest change I ever saw in the smaller calibers.
     
  11. Shopfox

    Shopfox Well-Known Member Supporter

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    I gleaned another piece of useful information from Sierra. For increments of working up they go by 1% of the case capacity. so if a cartridge uses 30 grains they would use 0.3 increments if the capacity was 40 grains 0.4 grain increments.
     
  12. Dallas53

    Dallas53 Well-Known Member Supporter

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    i think a chronograph is an extremely useful tool for reloading. it's something i really need to add to my collection of reloading equipment.

    it gives a very accurate indicator to true velocity of your firearms. many times the velocity data listed in load manuals is based upon their test rifles or barrels. as we know, every firearm is different. and barrel length does have an effect on muzzle velocity.

    a chronograph also allows a person to see if the reloaded ammo is consistent in it's powder charges. the more consistent the powder charges, the less variation in velocity readings one will get.

    primers? well, for the negligible cost difference between brands, i'm willing to give them a try. if they show an increase in accuracy, then all is good. if not, still all is good and nothing is actually lost.

    seating depth? definitely something i believe a person should experiment with on their rifles. in many cases it can show an increase in accuracy. some rifles, as i have found out, not that much difference. but as all rifles are different, you just never know until you try it out. the only bullets i don't even bother with in adjusting seating depth are those with a cannelure groove for crimping. another area that some gain accuracy from is from neck tension, and not using any crimp. now on crimping, for myself, it depends upon the cartridge, the firearm and it's use as to whether i crimp or not. and neck tension is an area i want to explore in more depth with some of my cartridges and dies to see if there is an increase in accuracy.
     
  13. Txhillbilly

    Txhillbilly Well-Known Member

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    Shopfox,Since you're loading the 6.8 SPC,what magazines are you using?
    Have you measured the maximum inside length of the magazine's?

    I use ASC brand 6.8 magazines for my 6.5x6.8 wildcat,they allow you to have a COAL of 2.300"

    If you can measure your chamber and get a measurement of where the bullet hits the lands,then you will know where to start on your seating depth.
    I always start my test loads seated at .010" off the lands if they will fit in the magazine. If the measurement is longer than the magazine,I will start seating the bullets at the maximum magazine length. Then I will test the best shooting load at different seating depth's to see if the groups get smaller or bigger,and use the best seating depth.
    The style of bullet also will determine your seating depth,you want to have enough bullet in the case neck to support the bullet and also have enough neck tension on the bullet to hold it in place. For bolt action rifles,I like to have .002" neck tension on the bullets. For AR's,I like to have .003"-.004" neck tension on the bullets.
    I use neck bushing sizing dies on all my rifle's that I want to get the ultimate accuracy out of. I can change the neck tension by changing the bushing size.
    On standard style dies,you can adjust your neck tension in most cases,it just takes some work to do it. In most cases,you won't need to do it just starting out.

    The main thing about getting into reloading is don't get too wrapped up in all the stuff you read. Get comfortable doing the basics,and enjoy shooting your own ammo. Your accuracy will automatically increase when you find the right powder/bullet combination's. Don't try to become a benchrest reloader,it will drive you crazy,and do more harm than good when it comes to accuracy out of your firearms.
    It's a simple process,size a case-prime a case-put powder in a case-and seat a bullet. The more you complicate it,the harder it becomes!
     
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  14. Shopfox

    Shopfox Well-Known Member Supporter

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    I'm using steel PSA magazines. I've read they are made by D&H. I'll check max length when I load up next. I loaded 2.267 so far. At the time, I didn't measure to see how much closer I could go. From memory I'm guessing 2.280. No way my mags go 2.30"
     
  15. Shopfox

    Shopfox Well-Known Member Supporter

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    Well, ammo's reloaded and ready to go. I went in 0.3 grain increments, until I got closer to the top, then went 0.2 increments. I'm staying 0.4gr under the published max load. For now, I loaded these rounds to 2.250" based on my manual.

    I measured my magazine, and was surprised. 2.30" is the maximum inside length for the magazine.
     
  16. Txhillbilly

    Txhillbilly Well-Known Member

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    Don't be afraid to load to the book maximum, just keep an eye on the brass and primers for pressure signs.
    Marks on the case head from the ejector, bent case rims, flattened primers, or cratering of the firing pin strikes are signs of high pressure and easily seen.
     
  17. Shopfox

    Shopfox Well-Known Member Supporter

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    Went to the range. Probably best trip ever :) I was running short on bullets, so had to ration and do 4-shot groups. The higher weight charges show a different gun.

    28.8 gr: 1.0"
    29.1 gr: 0.75"
    29.4 gr: 0.81"
    29.7 gr: 1.03"
    30.0 gr: 1.06"
    30.2 gr: 0.78"
    30.4 gr: 1.09" (removed a called flier)
    Average of 7 groups: 0.93"
     
  18. dwmiller

    dwmiller Well-Known Member

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    Now that is improvement! Way to go.
     
  19. Shopfox

    Shopfox Well-Known Member Supporter

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    I saved a target of factory ammo (SSA and Hornady Match) "before".

    I'm really happy with the "after". For what the rifle is, and how I intend to use it. I can't justify doing more tests and trials. The 30.0 gr was a completely wrong number. I went through everything with calipers later. It was 0.825". I must have measure outside to outside while sitting in kid pickup line.

    30.1 is where I'm going to stay at. It fills the case well, elevation between 30.0 and 30.2 is near identical, and both groups were clustered tightly (the extreme spread looks good at the lower end, but the groups appear more "open").

    Next step will be loading up some 444 Marlin rounds :)

    Guys, Thank You for the tips and feedback. You really shortened my learning curve, and helped me do so in a safe, efficient manner. Thanks Again!
     

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  20. Dallas53

    Dallas53 Well-Known Member Supporter

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    vast improvement Mr. Shopfox! awesome! :D