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Advice on fine tuning match load

Discussion in 'Ammunition & Reloading' started by assault15, Jul 22, 2012.

  1. assault15

    assault15 Corvallis Member

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    I would like to know what you match loaders do to fine tune your loads. I am trying to break the 4" at 600 yard 5 shot barrier and I am having trouble. The .308 load I am tinkering with is 43.0gr of Varget, in Lapua brass, pushing a 175gr SMK at 2649fps from a 22" barrel.
     
  2. Blitzkrieg

    Blitzkrieg WA Well-Known Member

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    Tell us first what your procedures are for case prep
     
  3. assault15

    assault15 Corvallis Member

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    The brass has been fired 5 times. I anneal every 3 firings. I first deprime using a wilson decapping unit. I tumble in fine corn media with non ammonia polishing agent. I then use imperial sizing wax and resize using a redding f/l s bushing die with a .335 TiNitride bushing for 0.0015 neck tension (a little light perhaps). I then trim, using a wilson trimmer on a sinclair stand to 2.005". Next I debur and chamfer using an rcbs hand tool and clean the primer pocket (flash hole was debured before first firing). I tumble for another 1/2 hour to clean off residue. Primer seating is accomplished using a 21st century benchrest unit at 13 clicks from bottom.
     
  4. millwrt52

    millwrt52 Kelso Wa Member

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    If you have done your load development and have an optimum charge weight, the next step would be to play with seating depths. Then again, it maybe that is the best your rifle or you can do. Actually, holding 6's at distance isn't bad at all, but I understand.
     
  5. assault15

    assault15 Corvallis Member

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    I know the rifle is capable of better groups than it is producing at least from what others are saying. Who knows maybe I am the only honest one. The rifle is a GAP Crusader with the 1/11.25 Bartlein so it is no slouch as far as performance. I want to know what benchresters do after they have settled on a powder and weight. Do you shoot 5 shot groups or another ladder test at long range?
     
  6. rodell

    rodell Newcastle, WA Active Member

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    If you are certain you have an optimum charge weight (OCW), then you adjust seating depth. Depending on whether you are comfortable at the lands, start there and work backward. If you aren't, then try .005" off the lands and adjust shorter in .005" increments.

    It is important you have an OCW, though, or any small deviation in temperature or charge will open up your groups and you'll chase your tail (been there, done that).
     
  7. PBinWA

    PBinWA Clark County Well-Known Member

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    How does it shoot with FGMM 175 SMK's or the GAP recommended Copper Creek 175 SMK's?

    I would try some factory ammo to see if it makes a difference. Then you can eliminate whether or not it is the ammo and focus on the gun and the shooter.
     
  8. Blitzkrieg

    Blitzkrieg WA Well-Known Member

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    Bullet selection is critical.. most weapons have a preference for a specific bullet type and weight.. and even the manufacturer can make a difference

    Another step that comes to mind is deburring and uniforming the primer flash hole.. also the primers used can make a difference in uniformity.. try match primers
     
  9. deadshot2

    deadshot2 NW Quadrant WA State Well-Known Member

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    Was talking to a fairly well renowned shooter at our range several weeks ago. A guy who broke his own World Record three times in one match.

    He said you can play with all the things you want. Buy the best brass, weigh powder to the exact granule, sort your bulllets, etc. but if you don't see to it that you have the correct neck tension your groups won't ever shrink to where you want them to be.

    It all starts with the case. First, start with some new brass. Lapua is just about as good as it gets. Go out and shoot the brass once using all your mis-matched bullets (weight, base to ogive odd measurements, those that just look bad). This will fire form the brass to your chamber.

    Then Neck Size. To start simple, get a Lee Collet Die. No lube, forms the neck on a mandrel rather than bulling a ball through which can make for crooked brass.

    Next, use an expander die like a Sinclair Oversize expander. This will make sure that the neck ID is the same, usually .306". This will make the case Neck Turning tool mandrel uniformly.

    Trim the brass to length. I usually use 2.010 rather than the common 2.005.

    Neck turn the cases. If you don't have a custom chamber that requires a specific neck thickness, just turn so the outside of the case neck is about 75% - 90$ "true". No need to take more material off than that. For my Lapua Brass this is about .014" of so.

    After neck turning then you could de-burr the flash hole but I've found that with my Lapua brass this is just a time killer. Likewise for primer pocket uniforming.

    As for bullet prep, this will depend on the kind of bullet you use. If a BTHP, consider a Meplat Trimmer. This is a tool that cuts a small amount off the rough part of the hollow point, making the bullets the same length from ogive to tip. The Montour Custom Rifles Mepat Trimmer also uses a tool to chamfer the inside of the hollow point mouth for a nice finished look. This process will reduce the BC of the bullet slightly (2%-5%) but they will all fly more uniform than those that have a meplat that looks like a broken tree stump.

    Now you're ready to load. If you want bullets to fly true, and hit the same point, they have to leave the barrel at the same speed. This is achieved by making sure the powder load is the same, cartridge to cartridge. If you are just a "dumper" from a powder measure, checking only a few loads, then you'll probably have a wide variation. Best way is to make sure you have a nice accurate scale, beam or quality Digital (I have an RCBS in my Chargemaster and a Dillon D-Terminator for my "development station") scale. Drop the charge, or even dip it with a scoop, then trickle the charge to an exact weight for every case.

    Seat the bullets and pay attention to the felt effort to do so. If you have a case where it feels like the bullet just slipped in, set it to the left. If you have one that seems like it took more than the average amount, set it to the right. That should leave a whole bunch of "average feel" cartridges in the middle. Ones that had the same "feel" when you seated the bullets. If you only have a few of the ones that felt light or heavy, just use them for "foulers". If a lot, consider just grouping them into their own batch and shoot in their own match. Remember it's really about "SAME" rather than a specific amount.

    After all this work, it's still up to the rifle and shooter. To tighten groups, assuming you're shooting off a rest with rear bag, pay special attention to the rear bag. Line up your scope cross hairs on the target using front rest and rear bag and not touching the rifle any more than necessary. Rotate the bag under the stock so the cross hairs are at the highest point of travel. If the bag isn't straight under the stock it will raise or lower the Point of Aim and then when you pull the trigger, cause the shot to go "ca ca" when the rifle recoils. Once the bag is straight, then move forward or aft until you have the desired point of aim. When you then establish your grip, shoulder position, and cheek weld, make sure you don't disturb the bag. Adjust YOU, not the rest. Remember, it was perfect before you started to hold the rifle.

    Now for the hard part, pulling the trigger. If you don't pull the trigger so any movement imparted to the firearm isn't perfectly aligned with the bore axis you're essentially changing the point of aim just before it goes "bang". That makes it hard to notice. Try dry firing to develop your trigger finger technique. (At this point it also might be a good idea to have trigger pull checked to see if it's uniform, always breaking at the same pressure. Trigger pull gauges aren't all that expensive and they are a good indicator or when to separate the action from the stock so you can give the trigger assembly a good bath and re-lube)

    OK, I know, you asked "What time it is" and I answered by "building a watch". Sorry, but it's all connected.

    What I told you is a mixture of what I was taught and learned the hard way. I will say that it works. I only shoot factory rifles as I like the challenge of making one more accurate than the factory might imagine. Using the above process and techniques I have one old "shot out barrel" Remington .308 that still shoots .290 MOA at extended ranges (300 yards plus).

    Oh, by the way, did I mention Wind?

    Isn't this a great sport?:cool: We just need to make sure we don't end up chasing our tails so much that we disappear up our own------well, you get the picture.
     
  10. Darkker

    Darkker Mesa, Wa Active Member

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    I stumbled on this load, and have given it to 4 different people. Haven't found a gun that won't shoot it yet.
    WLR, or BR2 - BR2's lower the ES by about 15fps.
    Brass - Everyone will flame this, but I mix everything. I like LC, one buddy likes Lapua... Oh well.
    Bullet - 175 SMK
    Powder - Win 748 43grains
    Crimp - very light Lee FC
    Not home right now so I can't tell you my OAL. But I seat 1/32" off the lands.
    Best of luck.
     
  11. deadshot2

    deadshot2 NW Quadrant WA State Well-Known Member

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    Only problem I see with this "load" is that it doesn't show up anywhere in the Manufacturer's load map for a 175 gr bullet. Lee shows a very narrow load spread of 41.0 grains to 41.3 grains. This usually indicates that the powder clearly was not intended for this combination.

    If it works for you, great. I'd strongly recommend that anyone else use extreme caution with this powder, bullet, charge combination. Could have drastically different results.

    Might want to state the caliber. I'm just assuming .308.
     
  12. Darkker

    Darkker Mesa, Wa Active Member

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    So lets clear this up a tad...
    "The manufacturer"

    The data you quote seems to be from Lee's "modern reloading second eddition". Richard "compiled" his data from "powder suppliers".
    The data you list is for a failsafe bullet. It has long been advised that those bullets produce much different pressures than lead core bullets. Just like the warnings on Barnes X bullets, since it basically is one. I don't recall Richard passing that warning on in either of his books. Speer #13 who actually did do their own testing(just prior to Lee's publication)shows a range of 41-45 grains for all 5 of their 180gr bullets.


    So the Actual bullet manufacturer:
    Sierra's reloading manual Vol. 5, which is the current eddition. Page 540, yep falls within their range also. In fact 748 is used for all bullets in the 308. 110-200 grain bullets, and producing some of the top velocities across that range to boot!!

    Now the powder manufacturer:
    That is General Dynamics(Defense contractor), who Hodgdon buys ALL of their ball powder from. Hodgdon has the rights to sell the Winchester name. I did in fact call them(Hodgy) a month or so ago. They have always had a ton of info for 748, in a ton of cartridges. When I asked why all the info is gone, or horribly low pressure; they told me it was a contract dispute. They don't think that Ohlin is holding up their end of the contract(supplying current pressure testing), so they only published what was last given to them. They were quick to point out that it was so old, they couldn't say when the testing was done.
    A quick look to the current website however shows a Speer 180gr SP with a single load of 46.5gr.

    Since the OP gave the particulars for HIS 308 load, I didn't think I would have to point out that MY load was also for a 308.


    I do agree that everyone should use Extreme caution when reloading. There seems to be a lot of folks out there who give out bad information... Don't believe everything you read.
     
    PBinWA and (deleted member) like this.
  13. Blitzkrieg

    Blitzkrieg WA Well-Known Member

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    I prefer the Lee taper crimp for almost everything unless it's a channelured duty type load. It gives a uniform grip on the bullet
     
  14. deadshot2

    deadshot2 NW Quadrant WA State Well-Known Member

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    Lee Factory Crimp Dies are designed to apply the proper crimp for the caliber they are built for. That would be a "rolled crimp" for handguns or tubular magazine rifles (like 30-30's).