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Thread: Why not start with Distance to Lands, then figure a charge weight?

  1. #1

    Default Why not start with Distance to Lands, then figure a charge weight?

    I'm relatively new to reloading, so forgive my ignorance. But, it seems like from my reading most folks work on a particular charge weight with their intended bullet & powder and then after they have that dialed in they go for bullet seating depth.

    However, either on this forum or another, a lot of reloaders stated they got their most accuracy improvement from bullet seating depth, over things like brass prep, charge weight, sorting by weight, bullets & cases, .... If that is the case, why not work that up first & then go for the Optimum Charge Weight?

    Confused, help me out you experienced reloaders.

  2. #2

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    Most ammunition tends to perform best when it's at 85-100 % (sometimes more) case volume. SO the reduction in powder volume is counter indicated when working up loads for the best accuracy. A well prepped case is a plus in the accuracy direction. Bullet seating directly affects case volume and pressures which equal velocity. The distance off the lands isn't always critical or factory ammo would perform very poorly as it isn't adjusted to each individual firearm, just SAMMI specs which are cut into chamber reamers. We know that commercial companies wouldn't use a dull reamer or resharpen one; RIGHT. Many factors effect the bullet/rifle performance, but most firearms have a factory ammo that will push accuracy to the average hunters limits. "ONCE" we get beyond that then we judge group performance with a set of dial calipers not how much meat it puts on the table.
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    Sponsor ADfields's Avatar
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    The powder charge is what you tune out the gunís harmonics with. The harmonics (whip of the barrel) is the most detrimental thing to accuracy so first thing is to find a powder charge that will work with the gun . . . Then play with other stuff to fine tune. First the rough work then the fine tuning, the other way around would work eventually but is a bit like cutting a board off with a sander then trying to fine tune it with an ax.
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  4. #4

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    So then what I'm hearing is that distance off the lands is not that big of deal in a hunting rifle, unless your shooting red squirrels at 300 yards? But, just the opposite in the OP, optimum powder charge is more important? So I have a charge that I like right now, it shoots probably just over 1 MOA (3 shot group). Should I adjust the bullet seating depth, or be happy with it. I would not shoot beyond 250 yards & could probably hit a 6" circle at that distance. Seems like I should just be content with what I have & spend more time practicing shooting off-hand, sitting, & prone, ...?

  5. #5

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    Quote Originally Posted by Kushtekaa View Post
    So then what I'm hearing is that distance off the lands is not that big of deal in a hunting rifle, unless your shooting red squirrels at 300 yards? But, just the opposite in the OP, optimum powder charge is more important? So I have a charge that I like right now, it shoots probably just over 1 MOA (3 shot group). Should I adjust the bullet seating depth, or be happy with it. I would not shoot beyond 250 yards & could probably hit a 6" circle at that distance. Seems like I should just be content with what I have & spend more time practicing shooting off-hand, sitting, & prone, ...?
    The adjustment of Cartridge Over All Length might improve your rifles accuracy. It could also increase the rifles pressure if the bullet is pushed into the rifleing lands, causing problems. In some actions COAL is determined by action length/magazine length; Long projectiles in short actions might not work well. Also the bullet length needs to match the rifles twist ability to stabilize the projectile. Monolithic copper style bullets are longer weight for weight than cup and core bullets. Once you've decided on a load your rifle "likes" practice always helps.
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  6. #6

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    Thanks Yosemite Sam,
    That was a lot of info, put out in a brief & concise format. I'm going to go ahead & play with the COAL & see if I get any improvements. I guess that's the fun when reloading, trying to get some tight, on target loads. Thanks again for all your input.

  7. #7
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    Each of us has his own standards on how well a particular rifle should shoot and how much effort we want to put into making it shoot better but ADFields hit it. Barrel harmonics is first and type and amount of powder is very important with this. Brass prep usually tightens a group a little as do many of the other little things. OAL will have dramatic results in some rifle/bullet combos and very little in others. I have had better luck bedding the action and floating the barrel and then adding a pressure point at the front of the stock than much of my load development. This also has a big affect on barrel harmonics. Personally, I haven't had much luck with free floated barrels without adding the pressure point up front.

  8. #8
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    If you have a factory rifle barrel, you will often find you will run out of magazine room before you run out of room to seat to the lands. A lot of factory guns set the throat far out to prevent the heaviest (and longest) factory ammo from jamming the lands. For instance, if you have a .30-06 and shoot 150 or 165 grainers, you can seat the bullets out quite a ways and will probably run out of magazine room before you hit the lands. The Hornaday COAL gauges are what you need to do a good job. Money well spent.

    If you don't have the gauge, seat a dummy load out almost as long as your magazine will let you, measure it's length with the micrometer, then see if you can chamber it. Extract it carefully and re-measure it. This should give you an idea if you've jammed it into the lands and need to seat it in further.

    Even if I have a long throat, I usually seat my loads as far out as the magazine will let me and still feed reliably. Closer to the lands is usually better than not. But for hunting rifles, like rbuck says, you'll get more accuracy bang for the buck playing with your powder load or by cleaning up the barrel channel.

  9. #9

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    I always set my lengths first and then do charge weights. This way I know when I reach my max charge weight. If you go the other way as soon as you change length your charges should drop to safe levels and then build up so you don't build to much pressure. Just a different way to skin a cat I guess.

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    What I have taken to doing with a new to me rifle is buy a variety of factory ammo, just enough to get me a herd of brass going.

    Then measure the length from the case head to the ogive point. The pointy cone part of a bullet is the ogive curve. The point on the cone where the bullet meets the lands is (at least in my world) the ogive point. A bullet comparator (linky thingy: http://www.hornady.com/store/Bullet-Comparator-Kits/) will let you measure from the case head (bolt face) to the opgive point on the bullet.

    In a perfect world I find a load that shoots great from the factory, chornograph it so I can match that velocity, measure it with a comparator so I can match that length, and use a powder I already stock to make a similar load. Never happened yet, but it could.

    If I could only have one thing out of a reloaded cartridge I would want to match the barrel harmonics, that is have the bullet exit the muzzle when the muzzle is as small as possible and the rifling has the best grip on the bullet. 180 degrees out of phase, the muzzle will be at its largest and the rifling will have the least possible grip on the bullet at the worst possible moment.

    So primarily charge weight. But if you change the head to ogive length, that is change the "jump" between the seated bullet and the lands, you can and often will alter the pressure curve. Which changes where in the harmonic cycle the muzzle is when the bullet reaches the muzzle. Which changes (a little bit) the ideal charge weight.

    For a hunting rfile, I would take a 2MOA load that is easy to make - and practice with it a lot from the field positions; rather than develop a 0.0005MOA that is a real pain in the neck to make and not practice with them because they take so long to load.

    I mean really, a 2MOA load at 200 yards, a 4" circle is a dead with the first shot moose, and a dead with the first shot caribou, whether or not you can put your bullet through the triscuspid valve between the left ventricle and aorta.

    EDIT: When I have a factory load that shoots well I do load to that ogive length to start and see if any of my powders will work well at that length, inside the published charge weight limits.

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    323 showed me another good way to measure how far you can seat until you hit the lands. Take an empty case and use a dremmel or other cutting tool to cut across the case neck lengthwise in 4 different spots. This should allow you to put a bullet in the neck and tighten it down with your fingers. Then after you have inserted the bullet, slip it in the action and slowly close the bolt, then carefully extract it and measure. The lands will push the bullet down into the case until it fits, this should tell you how far the bullet can be seated before it hits the lands. It's the same principle as the hornady COAL guage, but sometimes the hornady dummy case isn't available, or really hard to find.
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    The first thing you should do is prep your cases. If each case is prepped exactly the same, then a bunch of variables have been removed before you even get to loading.

    To reduce you workload, just buy the brass from Nosler. It truly is ready to load.
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    The Berger web sight discusses this. They suggest finding the "sweet spot" for bullet COL and then adjusting charge weight from there. They have you load something like .1 .07 and .05 from the lands with middle of the road charge. Shoot them at 200 yards and one of the loads will show a significantly better grouping assuming you shoot well. If you can't shoot well to 200 yards you don't need to do this test.

    Take that COL that grouped the best and increase the charge weight by .2 and shoot them at 200 yards again. Track what bullet goes where and watch for pressure signs and velocity deviations. When your harmonics are good, there will be a group of bullets that are real close together and then they will spread out some. The group that is close together is real close to your optimal COL and Charge. You can tinker from there with small changes in COL and small changes in powder charge to dial it in.

    I have found fantastic loads with this method several times. The most notable the first time to the range with a 375 Ruger. The testing revealed a 1 moa 270 TSX at 2600fps. No further testing needed. We fired 8 shots that day out of the rifle. We have tried other loads, but nothing has ever been better.

    I shot 200g TTSX out of my RUM. I never found a group that was better than 6 MOA, so gave them up pretty quick. I use 168g TTSX which it seems to like. Same testing procedure and I found a good load after a few tries. I have dialed it in further by neck sizing, and changing from match primers to non match. Tried crimping but it gave pressure signs. I want it to be a tack driver for eventual 300+ yard shooting. So I am picky about the results.

    A buddies 300 WIN had 1 moa with 180ttsx his second time out with a close enough to max load to be happy (forgot the chrony numbers). He shot less than 20 rounds.

    My old 300 win took 4 different range sessions to get something to work. Tried 3 different powders until I found RL22 to work real good. Then it gave me 2 moa at it's best. I looked into gun problems and the throat was REALLY long and it was rusting. I used the action for a donor and made a 264 win. I just went through my first round of testing this weekend and my first test revealed all COL to shoot about the same, and not good. I will try another powder and try the COL test again.

    Seems like if a gun is a shooter, then there will be plenty of loads that will get you close to the magic 1 moa with good loading practices. Below 1 moa is exponentially more difficult it seems and you juggle a lot of really little changes. If a gun just aint shooting, then maybe you need to spend time with the gun. Floating the stock, accurizing the action, making a pressure point (I have never done this), fixing the crown, better trigger and glass etc....

    hope that helps.

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    Here is a nice link with plenty of detailed information to broaden your knowledge:

    http://www.bergerbullets.com/wp-cont...13/03/COAL.pdf


    The following is a method discussed by Berger to find your best length. I use this technique almost exclusively with minor changes to suit my style.

    http://www.bergerbullets.com/getting...in-your-rifle/

    The changes I've made for my preference are:

    1.) Use a powder that provides nearly 100% case fill and nearly max published velocities of production ammo in the same bullet weight range.

    2.) Use about 90% of that load to start the seating depth testing.

    3.) One depth will clearly shoot better than the rest.

    4.) Adjust your charge up or down in volumes that equal about 1% of your velocity and monitor your ES, SD values as well as your groups. A wide ES will not group well at long range even if you get a nice group at close range.

    5.) Example, if you're shooting 2800 fps with 57gr of charge that is ~4.912 fps per tenth of charge. This means approximately .6gr of charge increase will net about a 29 fps increase in velocity. When your increase in charge doesn't net a predicable increase in velocity you are very close to your max charge.

    The picture below is an example of seating depth testing. The groups are all shot from my .375 Ruger with identical load prep. The only difference in each group is seating depth. One group clearly defeats the rest. I further tweaked that load until I was satisfied with the velocity. This particular load is very consistent and always shoots better than .5moa from that rifle. I have gone back and tweaked several of my best loads in all of my rifles with the above techniques and have been very satisfied with the results. There is not a rifle in my safe that isn't .5moa or better.

    A lot of precision shooting depends on your discipline too. Don't rush a shot, don't shoot from an unstable position, don't shoot on a windy day or suffering from a hangover or shaky from to much coffee or an empty belly. Load development is a testing process and your work is only as good as your test. Anyone can load powder into a case and make it work. Only careful prep and honest testing will net great repeatable results.

    Hunting of course is shooting in unpredictable weather. However, if you test and develop your load in controlled conditions you will have a higher level of confidence in your rifles ability when you march out in the woods after that moose. A miss will clearly be your fault not your rifles.


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    Member marshall's Avatar
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    A close friend of mine that doesn't really get into posting his groups has adopted the Berger techniques as well. We share data on a regular basis on multiple rifles we load between us. Together we are currently loading 23 different cartridges with outstanding accuracy using those techniques.

    Three of his recent 100 yard 5 shot groups shooting a .416 speak volumes for the legitimacy of careful load development. These are off his shoulder and a sand bag with a 6X scope, no fancy target stuff or vises.


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  16. #16

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    Quote Originally Posted by duckslayer56 View Post
    323 showed me another good way to measure how far you can seat until you hit the lands. Take an empty case and use a dremmel or other cutting tool to cut across the case neck lengthwise in 4 different spots. This should allow you to put a bullet in the neck and tighten it down with your fingers. Then after you have inserted the bullet, slip it in the action and slowly close the bolt, then carefully extract it and measure. The lands will push the bullet down into the case until it fits, this should tell you how far the bullet can be seated before it hits the lands. It's the same principle as the hornady COAL guage, but sometimes the hornady dummy case isn't available, or really hard to find.
    This is exactly what I've done, seems to work well, at least my numbers have been consistent with this method. I use a bullet comparator to measure near the ogive. It's cheaper than the case length guage & I like cheap.

  17. #17

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    Great stuff Marshall? Exactly the kind of info. I was looking for. I have a charge that I like now I'm going to tweak the jump. I hope I can get as good a groups as you and your buddy.

  18. #18

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    Quote Originally Posted by marshall View Post
    A close friend of mine that doesn't really get into posting his groups has adopted the Berger techniques as well. We share data on a regular basis on multiple rifles we load between us. Together we are currently loading 23 different cartridges with outstanding accuracy using those techniques.

    Three of his recent 100 yard 5 shot groups shooting a .416 speak volumes for the legitimacy of careful load development. These are off his shoulder and a sand bag with a 6X scope, no fancy target stuff or vises.


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    So when you are fine tuning the distance towards the end for your final load, what distance increments are you using to do that? .005 in.?

  19. #19
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    Quote Originally Posted by Kushtekaa View Post
    So when you are fine tuning the distance towards the end for your final load, what distance increments are you using to do that? .005 in.?

    to start I check max mag length and take .015 off of that for reliable feeding. I then measure the COAL with the bullet touching the lands. If it's longer than the max mag length I start at max mag minus .015 and get busy. If it's a target rifle and hunting isn't planned I don't worry about the magazine length as I will single shot load if necessary.

    Depending on the rifle, bullet, load combo I start at .025 off and go out in .025 increments with soft point, flat tip or round nose. With pointed bullets I'm .015 off and then generally go .030 at a time out to one step greater than .100 off. With Barnes I start at .050 and go out .025 at a time from that. Sometimes I may vary this a few thousands or even start just kissing the lands.

    Now to finally answer your question. Once a good group shows itself I go .010 each side and take that winner and go .005 each side. This may seem like a lot of bullets but it really isn't. I only shoot three shot groups until a nice load is found. Next powder charge tweaking is done and a larger string of the finished load is shot to get solid ES, SD data to work with.

    I use to load everything about .050 off and work on charge. I later found that I would have to go back and reduce the charge to work on seating depth then sneek back up on the charge. My current way works better for me allowing a quicker find and less bullets down range.

    I've taken bits and pieces from Berger, Litz, Tubbs and others by reading and watching videos as well as talking with a few bench rest shooters in my local area. It's not magic but it works. Proper case prep is essential too. You still have to use common sense and watch for all the classic signs discussed in reloading manuals.

    There are several powders that can be used in a particular cartridge. I like to find one that offers a full case fill with good speed and accuracy, it's a testing process. Sometimes it's easy and sometimes it takes a while.

    There are a lot of good shooters on this forum and several experienced reloaders that have their own methods. Some are happy with 1 moa and others are not. Some spend a lot of time trying and others get lucky right away. Some are into reloading to save money and others are trying to improve their accuracy. It's all part of the deal. For me it's therapy, hobby, pleasure all wrapped into one.

    My daughters .243 was driving me nuts. I used a few of the traditional powders listed as best accuracy in several manuals and couldn't get it to shoot under 1 moa with four different bullets. I tried the Scenar, VLD, Nosler BT and Partition. Finally using the seating depth test and a nearly full case of a slower powder it came in nicely. Currently the rifle is better than .5moa and quite nice to shoot. Below is the thread on that sequence.

    Sorry if this is getting boring...

    http://forums.outdoorsdirectory.com/...Win-test-loads

  20. #20

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    marshall,
    On the contrary I found your reply interesting & well written & look forward to reading further about your daughters 243 load development. I may just have to steal your method, as it makes sense & I'm always looking for the best accuracy & like yourself: "For me it's therapy, hobby, pleasure all wrapped into one." Cheers

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