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off the lands measurement?

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  • off the lands measurement?

    Anybody can throw a bullet together but...

    Ive been getting into handlaoding pretty serously latley. Everytime I relaod some ammo I find myself trying harder to make my bullets a little better or a little more perfect I guess. The only variable that I havnt conquered yet is the measurement between the bullet and the lands. How is this done? This called haedspacing right? I want to nail this one down cuz I know all bullets are shaped differently. And I want to make sure I dont screw something up!

  • #2

    When I am working up loads and over all lenght(OAL) is in dought I use a Stoney Point OAL Gauge. By using this gauge I can get the exact OAL for that bullet in MY rifle. It becomes more incritical when you are loading bullets of the Barnes brand. You can get them from most all places that sell reloading items. You also need to purchase the brass for what calibers you are reloading for.


    • #3
      What I do is smoke the bullet to figure out when I'm hitting the lands. All you have to do is light a match and hold it to the bullet on a dummy cartridge until it turns fairly black. Then, run the bullet into the chamber and pull it back out. If there are marks from the rifling you are too close and need to seat the bullet deeper. If there aren't any marks you can seat it a little longer. Keep going until you just barely get marks on the bullet. Seat your bullet at this length minus .050" (this is the distance recommended for the Barnes bullets I load but yours may be different).
      "Beware the man with only one gun; he may know how to use it."


      • #4
        still confused

        Even if you make the bullet the same oal as factory recommended wont the oal be different for a bullet made by a diferent brand do to the shape of the round?

        In my case im loading .450 marlin and im using kodiak 350 grn bullets instead 350 grn factory hornady. the bullet shape is very different between the two. Im had to make oal about .019 shorter to get proper feeding of the round.
        I guess the questin now is how do I find out how far out I need to be for this load? is it the same as factory?

        Thanks for input


        • #5
          Overall Length

          Magnum man,

          Several things here. But first, what you assemble is called a cartridge, not a bullet. There are four parts, case primer, powder and bullet.

          One: If you need to load to a certain length to get it to feed, that's what you do.

          Two: the 350 Kodiak is not a lot different from the Hornady Factory 350 grain flat point. The Cannelure is in a different spot I think but when seated to the same Overall Length as the Hornady bullet it will feed in the Marlin. (Mine do.)

          Three: How do you find out how far out you need to be for this load?
          Well, If it feeds and IF it doesn't jam into the lands and If the shape of the bullet allows a good crimp at the Overall Length you're using, Then you're there.

          Four: No that isn't headspace. It is just the distance the bullet travels before it engages the rifling. If jammed into the rifling it can cause excess pressure. If it jumps too far accuracy may suffer.

          The 450 Marlin doesn't have a lot of options when using the 350 grain bullet. You cannot use the 350 grain Speer or the Kodiak made for the 458 Win Mag, the ogive (slope of the nose) is wrong for the 450 Marlin and it can't be seated to the correct Overall Length.

          If you want to find the jam length, or contact lenght, for this or any bullet in any caliber, you can do that with the Stoney Point system. (get one for the type of rifle that you can't remove the bolt from, the angled one.) They have a threaded case for your caliber, you'll need one of them or use any fired case and size it down only 1/16-1/8" and seat the bullet you want to use just into the case 1/8". Then smoke the nose as Kay9Cop said and chamber it by hand and close the bolt then open and extract it. The round will be jammed into the lands to its contact length. Then measure overall with a dial caliper and that is the contact length with that bullet. You may have to seat it shorter to make it feed in the lever gun, but that is the way to find the lands in your rifle. Do this with every bullet you use and write it down in your log. Typically you will be from .010" to .050" off the rifling for best accuracy. Just seat to an overall Length .010-.050" shorter. You're not dealing with a Swiss watch with the 450 Marlin so just seat it to best feeding length and go for it. Hope this helps.

          Is there nothing so sacred on this earth that you aren't willing to kill or die for?


          • #6
            seating depth?

            I'll have to second what many have said here already. Magizine length/ smooth feeding is paramount in a hunting rifle. I think is was Bob Hagel who was one of the first to suggest smoking the empty assembled bullet with a candle, to determine seating depth. Keep this process up until the rifle land marks disappear, and then seat one screw turn deeper on the bullet seating depth screw and your set.He also suggested this process for resizing die adjustment on the case shoulder , for a SLIGHT crush fit. The only diffrence is that the die is set to just miss the shoulder angle on a fired case and not set one turn deeper. This produced some of the best results for me with my rifles/reloads. Reguards Bill.
            ; for them that honour me I will honour, and they that despise me shall be lightly esteemed. 1 SAMUEL 2;30


            • #7
              cartridge OAL

              The easiest way i've found to smoke bullets is to use an oil lamp.
              By adjusting the flame you can make the lamp smoke alot.
              Hope this helps.


              • #8

                thanks for the info. Its all easier than I thought it was. thats basicly what I did.

                I just kept sizing the round until barely fed and then gave another 1/4 turn or so on the die so it fed good every time. and made sure to test every few rounds that I made with a caliper for consistency.


                • #9
                  Originally posted by Magnum Man
                  thanks for the info. Its all easier than I thought it was. thats basicly what I did.

                  I just kept sizing the round until barely fed and then gave another 1/4 turn or so on the die so it fed good every time. and made sure to test every few rounds that I made with a caliper for consistency.
                  Since bullets aren't made identically the same, the distance to the lands changes from bullet to bullet (for example a Barnes 180-grain TSX's shape is different than a 180-grain partition of the same caliber). The easiest way to measure the overall length, or the distance to the lands is by using a set of gages such as the ones made by Stoney Point. If you buy the kit, buy both gages because you will use both. The kit comes with a case of the caliber you order, but you can send a fired-once case to Stoney Point and they can thread that case for you to use with the kit. I just use the standard case that came with the kit, and it works fine.


                  • #10
                    measuring OAL

                    One thing I found a long time ago for measring OAL by using a caliper with flat jaws is that many of the spire point bullets give inconsistent lengths because of tip deformities. I modified a dial caliper that is dedicated to that purpose. I simply used a small caliber standard ogive seating plug out of an old die and glued it onto one of the flat jaw faces on the dedicated caliper. When I log the OAL of a particular round it is noted as an "index" since it will not be the same as the OAL from bullet tip to base- as is cited in most of the manuals. For example looking at a group of loaded rounds, handy for this example are some 338-06 with 225 Accubonds. Measuring one with the dedicated caliper that uses the bullet seating plug contacting the forward ogive I get a reading of 3.560" and that figure is entered in the log book as "Index OAL 3.560". Measuring the same round from tip of bullet to base with the flat-jawed caliper I get 3.481". Experience has shown me that by using the seater plug caliper indexing I get much more consistent and repeatable measurements. My bullet jam measurement for that rifle in 338-06 and that bullet (225 Accubond) is "Jam Index OAL 3.575" and is so noted in the load log for that rifle. So by using those figures the round I just measured will be .015" off the lands for that rifle. If I load a different bullet or try a different seating depth I know I can go back to exactly an "Index OAL 3.360" and be exactly .015" off the lands for the 225 Accubond. Using the tip to base measurement with the flat jawed caliper has never proven to be as exact or repeatable because of the bullet tip defects, etc. Just an idea for a little better way to measure spire point bullets more consistently.


                    • #11
                      Years ago, when I got into reloading, I ran across a write up simular to the one below. I have used this method for years and it has worked well. This is for a bolt action though. I think the important thing in using this method is to make a couple to double check that the bullet isn't sticking and pulling out a tad when you eject it.

                      Someone mentioned the soft tip deformity in regards to oal, good point that should be taken into consideration. Another issue is bullet weight...measure the weight of all the bullets in a new box sometime....interesting.

                      *****CASE OVERALL LENGTH*****

                      To begin I always trim my brass to a consistent 2.484" and ligtly deburr them. I also deburr the primer hole to ensure consistant ignition of the case upon firing.

                      I prefer to seat the bullets in my reloads to the point where the bullet is just off the rifling. This Overall length varies for each bullet as the shape of the bullet can affect how far the bullet can be extended before the bullet will strike the rifling. The way I usually determine this dimension is to take an empty resized case and seat a bullet to a long overall length. I take this cartridge and slowly try to push it into the chamber. At the point where the bullet strikes the rifling you will feel pressure as you can force the bullet into the empty case using you rifle’s bolt. Once the bolt is closed I remove the cartridge and set my seating die to the length of this cartridge.

                      From this point I seat a second bullet in an empty case to the same length as the previous cartridge. I blacken this bullet using carbon from a candle (Obviously don’t do this near gunpowder!). I again run this cartridge in the chamber looking for signs that the bullet strikes the rifling (There should be marks in the carbon). Take a third cartridge and seat the bullet to a slightly shorter COL, blacken it and evaluate if it strikes the rifling. You can use the same bullet and cartridge to repeat this process but I prefer to use at least two so that you always have your "longer" cartridge as a reference.

                      Once you have a cartridge that doesn’t hit the rifling I would measure the overall length using a micrometer and record it for future reference. I keep some of these "Maximum Off Rifling" cartridges as samples until I have completed my load development for that particular bullet.

                      I use this length as the longest COL and I will try a few lengths which I will discuss later.




                      • #12
                        Magnum Man:
                        Murphy’s explanation was pretty thorough, but I’d like to chime in too.

                        For OAL, Seating Depth, Distance to the lands, etc., I use the following method.
                        Size the neck of a case a tiny bit, enough to hold a bullet snugly, but not too tightly.

                        Seat a bullet in that case that is obviously too far out, and carefully chamber it, then carefully remove it, making sure you hold it straight, if your rifle has a plunger type extractor.

                        Measure the OAL to the TIP.

                        Take this “Jam Length” “Dummy Cartridge” and adjust your seating die to it.

                        Readjust the seating die, and remeasure the OAL to the TIP, until it is .030 shorter than what it measured when it was at “Jam Length”.

                        I load the batch with that seating die adjustment. Smoking or Inking the bullet on a cartridge is a good way to make sure you are NOT touching the lands.

                        While it is true that the OAL to the Tip varies between bullets when the tips are deformed, but I’m only measuring ONE bullet, and my seating punch doesn’t contact the tip, but the Ogive slightly below the tip.

                        Using the Stoney Point tool to find the OAL to the lands isn’t something I’d recommend to a Brass Monkey.

                        As has been mentioned, sometimes you have to seat to a cannelure groove for crimping, or are limited by magazine length.

                        Smitty of the North
                        Walk Slow, and Drink a Lotta Water.
                        Has it ever occurred to you, that Nothing ever occurs to God? Adrien Rodgers.
                        You can't out-give God.


                        • #13
                          Magnum Man,
                          RCBS makes a Precision Micrometer that is basically a duplicate catridge and can be chambered in your rifle. You then remove the cartridge and measure it's overall length. As others have pointed out, you should measure from the top of the ogive of the bullet not the tip as this is the first part of the projectile that will contact your lands & grooves. I use a Davidson Seating Depth checker to take this ogive measurement and Sinclair Int. makes one that works well too.


                          • #14
                            Well, one other option...

                            I take a fired case that will chamber in the rifle I intend to load for, then slightly pinch the neck so that it will hold the bullet I want to use. I use a black marker to put a couple of lines on the bullet, then just barely start it into the case. I insert it into the chamber (with an 03 or a Mauser, I remove the extractor for this, or insert the cartridge rim under the extractor before putting it into the chamber). Carefully remove the case after closing the bolt, then measure the overall length. I try it three or four times to ensure I'm getting a consistent measurement, then set my die up to give me a finished round the same length. Sometimes, I'll give the seater a half or full turn down, just for grins, but not necessary.
                            Oh, the marks on the bullet...if the bullet sticks in the bore, it can be pushed out, then reinserted into the case to the point where the marker was scraped off, giving the point where it ceased forward movement.
                            Explanation is a lot worse than actually doing it, a prime example of making a short story long......


                            • #15
                              be careful about trying to get the bullet out too far, it can be a hassle if you are not getting a good bit on it and allows it to move or worse yet fall can happen. if you are using the tsx you are prolly in luck cause they are way long. oddly my gun really like them seated awful deep


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