Is there a way to tighten up velocity, ES, & SD?

Discussion in 'Long Range Hunting & Shooting' started by FlGunner, Aug 13, 2017.

  1. FlGunner

    FlGunner Well-Known Member

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    So I've been reloading my own ammo for close to a year now and figured a few things out but still have a ton of questions. So I've found a couple of loads for two of my rifles that shoot excellent but like many on here, I like to try new things and make an excuse to go to the pasture and shoot. I recently acquired some federal brass (7mm Remington Magnum) and I'm getting great groups (100 yds) with the 168 Berger classic hunter. My velocity is ranging around 2950 with 68.5 grains of Ramshot Magnum. The spread is 55 fps and I'm wondering if there's anything I can do to eliminate problems on my end and make this combo work better. I haven't shot a true ladder but basically loading 5 rounds in different increments and shooting groups over a chrono. Dies are the basic Hornady 7mm Remington mag Fl sizer and bullet seating die. I use a Redding competition set for a 243 and feel it's better quality but can quantify that since I do have a load using Retumbo and Hornady brass that's shooting the same bullet at 3000 and Es of 10. I've only used CCI #250 Magnum primers.
     
  2. FearNoWind

    FearNoWind Well-Known Member

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    While I try to avoid going nuts over SD/ES an ES of 55 fps would cause me to go back to the drawing board. It's all in the load, of course, so it is possible for you to tune it a bit tighter. When I'm happy with the MV I usually start looking at seating depth and/or primers. But only one at a time. Never a good idea to introduce two tests at the same time to analyze one problem.
    Once you get that ES down around 25 see what your 300 yard groups look like. I'm not suggesting you stop at 25, but when you get there and look at your 300 yard groups you'll have a better feel for what's working and what's not working so you can set meaningful goals for squeezing it down further.
     
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  3. Canhunter35

    Canhunter35 Well-Known Member

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    Try tweaking your load, somtimes dropping or increasing a little powder will keep you in your velocity node but may tighten you sd. Then adjust your seating depth. I have never tried switching primers but have switched powder to find a more consistent load. For example in my 300 wby switching from imr 7977 to imr 7828 dropped my sd from 35 to 5. Same velocity
     
  4. Schnyd112

    Schnyd112 Well-Known Member

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    I don't see anything about annealing your necks. This will help uniform the amount of pressure the brass puts on the bullet. Primer seating pressure I have also noticed a change in es, but that was from 15-18es to high single digits.

    Custom chambers also help, but as far as improving what you have, my first advice would be to anneal.
     
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  5. FlGunner

    FlGunner Well-Known Member

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    Thanks guys, I've never annealed case necks. But the rifle in particular is a factory Remington 700 sps with a Bell and Carlson medalists. No upgrades just free floated and bedded. The other rifle is a Remington Sendero with a few extras in trigger and winchester style safety installed on bolt (bought it used) and also bedded. The Sendero shoots everything good it seems. One thing I did was check my Lyman digital scale against an ohrus beam scale that I bought today ( looks ancient but the owner of the shop swears that's his same scale. He could've tried to sell me a more expensive one and didn't so I bought it) no two charges were exact on the scale that weighed the same on the Lyman digital so I'm gonna try to finish with beam scale for my final charge and see what gives. I will try you guys suggestions and as always thank y'all for the help.
     
  6. Schnyd112

    Schnyd112 Well-Known Member

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    Your electric scale may be building static. If you use a spray bottle to spray a fine mist of water around the scale it may solve your problem. I went back to beam scales though.
     
  7. Bravo 4

    Bravo 4 Well-Known Member

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    I keep hearing that HBN coating your bullets/barrel will help. I just started doing it with a new rifle so the jury is still out. I anneal my brass after every two firings as well.
     
  8. Ragnarnar

    Ragnarnar Well-Known Member

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    I don't see any mention of how you clean your brass. I've gone back to using Walnut shell because it's been pointed out that the fine layer of carbon that gets removed by other stainless or ultrasonics actually helps SD/ES by keeping the bullets from sticking to the brass.

    I've also had to neck turn on bad lots of brass to even out the es and sd.

    It's already been said but annealing (correctly and evenly) helped me out too. I'm doing induction annealing now, so I'm able to consistently achieve the same hardness on each case every single time, without worrying about tank pressure or flame temperature.

    Also primers. I like magnum primers in most rifles regardless of the charges or powder. I've found those to have the best sd's and es's because (I think) the larger spark ignites the powder more consistently. I do realize you're probably using magnums already but different brands might be "hotter."

    And make sure your primers are all the same depth. You can seat on the top of a coax press if you have one, or buy one of the fancy priming tools from 21st century or primal rights. My primers are always at the same depth thanks to Greg.

    And flash holes. Trim the crap in there, out of them if it's there. It literally actually like a flash hider on an AR with the primer spark so it helps to even them out on most brass.

    Also upgrading to a better scale so my charges were more consistent. Larger case volumes seem to be more forgiving too, so take heart in that.

    And I generally use premium brass unless I'm forced to use otherwise. I learned this the hard way. I don't think lapua does anything for your particular chambering, but one of the first observations I made when I started reloading for .223 back in the beginning was the groups shot with lapua brass were far superior to my other groups shot with lesser brass. Maybe buy a box of nosler or Norma and see if that helps?

    And I suppose component sorting will help. Same weight brass/bullets. I've never had to do it though.

    I've got my .223 bolt gun to 9fps es (using ball powder, if you can believe that) and my .308 bolt gun to 5fps using the ideas above. Both of those are with lapua brass and 20 shot strings. I'm expecting to be able to accomplish the same thing on my 7LRM with hornady brass, but I'm prepared to put in some extra work.

    I went on way longer than I wanted to, sorry for that.
    Good luck

    Edit: oh and maybe either crimping or jamming bullets. It will let the powder get a more complete burn started before the bullet starts to move. Thus a more even burn. Entropy is a cruel mistress some days.
     
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  9. Morse Industries

    Morse Industries Official LRH Sponsor

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    Make sure the brass is fire formed. also check their capacities. Our 338LM typically shoots the same fps at least 2/5 shots and es is low single digits. Your talking at least a 5in vertical at 700yrds with 50fps
     
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  10. buckfvr

    buckfvr Official LRH Sponsor

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    Full uniforming of your brass......primer pockets, flash holes, neck walls, do it all. Be sure to start with top quality brass or sorted brass. I will add I have a rifle developed with the same bullet that likes 2850fps for 3/4 moa 5 shot groups in a Savage LRH 7mm rem. After cleaning your brass the last time, be sure to brush the inside of the neck. Consistant neck tension is very important for es and sd. I turn my necks to be uniform and use a bushing die to get .002 neck tension. I'm in the process of switching to Redding type "S" dies to gain a bit more control over the shoulder bump. image1.JPG image1.JPG
     
  11. coyotezapper

    coyotezapper Well-Known Member

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    With ES of 50 I would try other primers first. If that doesn't work I would start with some of the other suggestions mentioned above starting with case capacity. Have not used Federal brass for years so I am not sure of the quality - meaning consistent case capacity. Two cases with different case capacity will give different velocities if you are not in a "true" powder node. Also, I would be careful when it comes to the inside of your case neck. I would only brush them in the cleaning process and leave them alone. They can actually be too clean and almost stick and not allow a smooth bullet release. This can often be seen in seating depth force. If bullets are harder to seat than normal they are too clean. Annealing is easy to do wrong so be careful there.
     
  12. TX Badger

    TX Badger Well-Known Member

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    My 7RM likes Nosler Brass if it turns out you are not happy with your Federal stuff. It's already weight sorted and primer pockets, length... are very consistent.
     
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  13. jshepherd61

    jshepherd61 Active Member

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    Many ways to tighten up your SD once you have the load worked up.
    1. Start with the case and fill, first by sorting to keep cases the same by fill volume (grains of water)
    2. Ensure they are trimmed the same length.
    3. Load cartridge length from ogave to base not OAL (most projectiles are closer in measurement from ogave to base than tip to ogave) this may change your COAL unless you're using quality match bullets! This ensures the same case volume.
    4. Weigh your projectiles even though you may have 168 gr VLD (example) not all are exactly 168 gr.
    5. Double weigh your powder on two different scales.
    6. Remember you will always have some SD just due to progressive fowling after each shot!

    I'm averaging a SD of 2 to 5 on most of my loads, you will also expand your SD if full length sizing vs neck sizing.
     
  14. bpcrshooter

    bpcrshooter Well-Known Member

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    not sure if anyone has mentioned but barrel will make a difference.... some are tighter some not so much. the sensitivity the powder has to heat will affect it as well!!! I have quite a few 7mmRM that I load for from stock to custom and I load the same in all and they all shoot 1/2moa @100 the custom does a lil better. In the propellant profiles book max charge of 75gr of h1000 was a little much. I load 74gr with WW, hornady and Nosler brass all hit in the same exact place. bullets are 160gr hornady match or eld, hunting 160 nosler partition. Fed 215match primers. As others have said anneal your brass, I trim everytime!! also I took my expander ball out and polished it( heat it up til is orange, let it cool, polish, then heat it back up to orange and quench) if you remove a few thou thats ok. primer pockets all uniform and flash hole de-burred.

    the propellant profiles book is a good tool I suggest everone have one!! lots of different powders and testing done with them. good luck!!
     
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