Finding distance to lands with freebore measurement

King_beardsly

MMPRL & Low Dollar Precision
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Minuteman
  • Jun 12, 2018
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    I'm working up a load for a new match rifle and I don't currently have hornady load n load gauge, is it possible to find the distance to the lands using the freebore measurement?
     
    Someone will post the video but basically remove the ejector/firing pin and load the round long. Drop the bolt handle, it won't go down, seat bullet deeper in case and repeat.

    As you get farther from the lands the bolt will drop farther. Seat bullet in smaller increments until it drops free.

    The video is better than my ghetto directions.
     
    Too much work for me. You can do the exact same thing without taking the bolt apart. All you need is a candle. But I've seen that exact same video posted by Spife for a match chamber with no free bore. Something like that yeah okay go for it if it is custom with necking turning and so forth. Still too much work for me. I prefer enough tolerances to avoid getting down in the grass. I don't like tolerances so tight that I can't shoot better than. I'm a .5 MOA shooter on a good day. Doesn't matter if the rifle is a .35 shooter or not.
     
    It's a custom Rockcreek barrel I had Josh at PVA do for me, so its sorta worth the effort. I shoots the gold medal berger pretty much lights out, but could be a little better with a worked up load
     
    The clearance between the neck of the chamber and the neck of the bullet doesn’t effect it, the ammo is either free of interference or it isn’t. In fact the more clearance and ample chamber room you have would yield even less chance of the case interfering with the measurement.
    Severe runout could effect it slightly but it will still be pretty good. And you can still candle it too. But with a micrometer top seater you can work it down .001 at a time to find it exactly. Leaving the ejector in will influence it way more than anything by forcing the entire side of the case into the side of the chamber. And once you’ve stripped the bolt a time or two you get good at it. Mines broke down in like three minutes including putting on the old shoe for pulling the firing pin spring. Glove in my left hand since my chamfered brass is sharp, bolt across my palm, use a case under the extractor to cam over and push the ejector in, punch between you fingers and a few taps with a hammer and the ejectors out.
    7034390

    7034391

    (Displayed on a bolt that doesn’t have either of those issues present though but it’s a demonstration of how I do it with all I have at hand this moment)
     
    I just followed the Wheeler method for finding the lands this past weekend on a new 6CM build from Greg Young at Southern Precision Rifles. Defiance bolt breakdown was easy with correct tools (Kleinendorst tool, correct size roll pin punch, etc). Used Redding competition seating die on once fired brass after FL sizing with 0.002 shoulder bump. The “feel” from slightly sticky bolt lift to smoot was distinct at 0.001 increments. I did this due to questionable results using Hornady modified case and Hornady Overall Length Gaige. I was using more pressure to insert bullet than I believed necessary to the point of jamming. Wheeler method results on 3 separate case/bullets were the exactly the same and 0.012 less than the average of 15 attempts with Hornady L&L gauge (threw out 6 or more measurements with L&L as obvious outliers). Saved the seated cartridges as baseline for chasing/correcting for throat erosion in the future. Now my OCD mind can let go of that nagging issue!!
     
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    It's all non sustainable once the barrel gets some wear and tear on. Then what? You have to have some sort of accurate +/- tolerance. One thing I don't like is a rifle that wants nothing but attention. What would be said tolerance? +/- .002" variation on OAL? I would bet that is too much for some people. I would bet some people go so far as to measure and seat per bullet for no apparent reason other than Johnny Unitas did it.
     
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    One step I would add to the Wheeler method above is to sacrifice one piece of brass and bump the shoulder back .020" to make sure that any impediment to the free bolt drop is only the bullet meeting the lands. Save the cartridge for chasing the lands as the barrel racks up rounds through it.
     
    One step I would add to the Wheeler method above is to sacrifice one piece of brass and bump the shoulder back .020" to make sure that any impediment to the free bolt drop is only the bullet meeting the lands. Save the cartridge for chasing the lands as the barrel racks up rounds through it.

    Just be sure to add that .020 bump back to the fired case size!
     
    No one has said that a good shooter with a good rifle and good ammo can’t do quite well.

    What’s that got to do with us reloading?

    And if the lands do erode far enough for you to notice a negative result down range it’s super easy to just remeasure and adjust accordingly. With a precise measurement it’s quite easy to adjust.

    Also, are you saying that factory ammo doesn’t have this same phenomenon working against them as well?

    And it’s not just for no apparent reason. It’s to develop a load competently. How can having better data possibly be as good as doing it blindly? I just don’t see why you seem to be against gathering good data in the easiest, fastest and best methods? If I didn’t know better it would seem that you are arguing for ignorance over information.
     
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    I'm scratching my head why LL uses Match factory ammo in a lot of his training videos and seems to do quite well on target.
    Time, I would bet is one major reason Frank uses factory loaded ammo. Some people have the time and desire to load ammo that will shoot inside factory loads.

    Finding a node that is wide concerning seating depth will help mitigate the affects of erosion for a longer period of time. I have rifles that have a .010” wide node and some with .003” wide ones. If you want to shoot small, you have to be on top of everything.
     
    Just saying we don't have to make it so complicated. The difference is immaterial down range. The greatest benefit of OCD methods is there is always bits and pieces of good technical information. Some people go to the extreme because they enjoy it. I like shooting dirty unannealed brass loaded up on regular dies and I'm not seeing the OCD reloading getting a material edge. In fact, I'm seeing people a generation before doing pretty darn good because they have no social media contact. People getting upset when somebody states it doesn't need to be this complicated at the end of the day. No need for that but it is taking newcomers and encouraging to skip reloading 101 setting them up to fail. I'm not an armorer. I'm just somebody that enjoys shooting and reloading only because the ammo is cheaper that way.
     
    I load primarily for semi-auto guns. Is there anything wrong with cutting a slit in the neck of a sized case, loading a bullet obviously on the long side, and pushing the dummy round into the chamber until it stops using a dowel? Carefully push the round out with a cleaning rod and measure. That is what I have been doing but I am new to trying to make real precision ammo and would welcome any opinions or better ways to do this.