Help .010 off the lands??????

Discussion in 'Reloading' started by bigbuck, Nov 25, 2009.

  1. bigbuck

    bigbuck Well-Known Member

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    I keep reading posts of were fellas say for example they shoot 210 bergers loaded .010 off the lands. My question is what type of tools do I need inorder to measure this and how do you do it?
    Thanks for your help.

    Bigbuck
     
  2. WEATHERBY460

    WEATHERBY460 Well-Known Member

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    I would like to know also...i think you can cut the neck vertically with like a dremal cutoff wheel, then insert the bullet, chamber, so the bolt pushes the bullet against the barrel, then extract and measure?

    But not 100 percent................
     

  3. goose

    goose Well-Known Member

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    One method out of a reloading manual I have is to take a fired case that has not been resized and the bullet you intend to use. Use a magic marker or other dye to mark the body of the bullet. Gently insert the bullet about 1/4 of the way into the empty case. Carefully chamber the round and then remove. The bullet may come back out, but will likely stick in the bore. Use a cleaning rod or other suitable tool to knock it out. The magic marker should be clearly rubbed off by the case showing how far the bullet had entered the case. You can then carefully insert the bullet back into the case for an overall length measurement. This may not work well if the case mouth is too loose fit around the bullet, in that case slightly resize it, just enough for a little neck tension.

    This method is the "poor man's" way of doing it if you don't have the money for the right tools. I use a RCBS precision mic set, which will tell you more accurately and also will measure how much your brass stretches in your gun so you know how far to resize it.

    Remember .010 off the lands is a good starting point, but no magic number. I suggest reading the article from berger about finding seating depth.
     
  4. mtelkhntr78

    mtelkhntr78 Well-Known Member

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    Hornady makes an OAL gauge called the "Lock n Load". It works really well and is super easy to use. I have both the Hornady tool and the RCBS precision mic and I found the Hornady to be the easier of the two. Thats my 2 cents.
     
  5. boomtube

    boomtube Well-Known Member

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    What the above posters are saying is that you first have to find where the lands meets your bullet, then back off what ever amount you wish.

    Several ways of doing that max OAL thing; the split case and soft seated bullet is one or you can simply use a wood dowel rod that will slide down the bore as I do. Close the bolt and use a knife blade to mark the rod square across at the muzzle. The remove the bolt, push the bullet you plan to use into the end of the chamber and hold it there, snugly against the lands, with a pencil. Push the dowel to contact the bullet point and mark it again. Measure between the two marks and that's your max OAL in THAT chamber and with THAT bullet. (I have both the Hornady Case Length tools and RCBS Precision Case Mic tools. Both types work okay but I have gone back to the old way because I find it consistantly more accurate.)

    Seat THAT bullet, the same one, in a sized but empty case at that exact length. Keep it for a reference gage. Then load your ammo and make it ten thou, or whatever you wish, less.

    You may not like the results of seating so close to the lands. Most factory rifles seem to prefer from .030" to four times that much jump. Many sporting rifle chambers won't even allow light-for-caliber bullets to be seated that far out.

    Seating at, or even near, the lands is really a BR techique for use with their lightly held bullets. It makes up for their lack of any significant bullet pull/tension. Sporting ammo would likely come apart with routine handling if we load as the BR crowd does so loading long has little to offer us. AND, doing so can cause it's own problems.
     
    Last edited: Nov 25, 2009
  6. woods

    woods Well-Known Member

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    I have tried all the methods and have the following observations:

    1. Splitting a sized case neck or slightly bending the neck of an unsized one where the bullet will slide in and out but with some tension was inconsistant for me. It was either the lands holding on to the bullet and pulling it slightly back out or the leade permitting a different depth due to very slight obstructions or the bullet being out of alignment. For gross measurements this will work if you throw out the out of line lows and highs and just take an average and are loading .050" off then you are close to OK

    2. Using a cleaning rod where you insert the cleaning rod down to the bolt face (make sure the firing pin is retracted) and mark it and then insert and hold the bullet against the lands with a pencil or wooden dowel, and insert the cleaning rod down to the bullet tip, mark it and measure between the marks. Also inconsistant with the possible reasons being the inaccuracy of marking exactly at the muzzle
    [​IMG]

    or the inaccuracy of measuring to the .001" between the marks
    [​IMG]

    3. The Hornady LNL OAL Gauge is an excellent tool but it takes some practice and some give up before you learn how to get the same results everytime. It uses a modified case where the bullet slips in and out and a rod that goes through the center and pushes the bullet to the lands

    insert the bullet keeping it back in the case
    [​IMG]

    put the case in the chamber and push the rod in to push the bullet against the lands
    [​IMG]

    measure either to the tip of the bullet or with a comparator
    [​IMG]

    With some practice you can come up with the same measurements everytime. It depends upon the consistancy of the force you push the bullet against the lands. But, you need to allow for the headspace or head clearance of the modified case unless you drill and tap your own cases that fit your chamber.

    4. The Sinclair OAL Gauge
    [​IMG]

    only fit some of my guns and the knurl knob was extremely hard to tighten down enough to keep it in place on the rod, even made my own slot for a screwdriver but eventually gave up on it.


    The best way I have found I will show you in the next post since there is a limit of 6 pics per post
     
  7. woods

    woods Well-Known Member

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    I have settled on the R P Tool 318-424-7867 r_reeves61@bellsouth.net shown here with the Hornady tool
    [​IMG]

    It is a stainless rod with a brass tip with 2 locking collets. Well made and worth every penny of the $25.00 I paid for it 4 or 5 years ago.

    You just insert the rod down to the bolt face (again make sure the firing pin is retracted) and lock the farthest collet
    [​IMG]

    Retract the rod, remove the bolt and put a bullet to the lands, the Hornady makes an excellent tool to do this or you can use a dowel
    [​IMG]

    Reinsert the rod to the tip of the bullet and lock the closest collet
    [​IMG]

    Measure between the collets
    [​IMG]

    The you can use that particular bullet to set the seating die with.

    The advantage of this tool is that it gives you 2 hard clean surfaces to measure between and it will work with any gun any caliber. The most repeatable and foolproof system I have found.

    Then all you have to worry about is the inconsistancies of the bullet ogives, the inconsistant seating depths that different bullet grips give, the inconsistant seating depths that different interior neck surfaces finishes give and how well your seating die is constructed.

    EDITED TO ADD: I completely agree with this statement from boomtube

    "You may not like the results of seating so close to the lands. Most factory rifles seem to prefer from .030" to four times that much jump. Many sporting rifle chambers won't even allow light-for-caliber bullets to be seated that far out.

    Seating at, or even near, the lands is really a BR techique for use with their lightly held bullets. It makes up for their lack of any significant bullet pull/tension. Sporting ammo would likely come apart with routine handling if we load as the BR crowd does so loading long has little to offer us. AND, doing so can cause it's own problems. "
     
    Last edited: Nov 25, 2009
  8. boomtube

    boomtube Well-Known Member

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    Woods, those are some good photos! And I lust for Brown and Sharpe calipers! :D

    I find the Hornady "modified cases" to be a problem in that they are seated to the shoulder, not the face of the bolt. Shouldn't be a LOT of difference but it's sure not the same as against the bolt.

    Marking my dowel squarely and consistly is assured by making the muzzle itself a guide for my knife or razor blade. Then, the only ambiguity is my ability to place the points of my dial calipers exactly on those marks! I also have your R-P type sliding collars for my rods or dowels but find the knife marks are just as easy, for me anyway.

    But, I've come to realise that there is no real need to be all that precise anyway, not unless I'm actually trying to seat AT the point of contact. I don't do that, so all I really need is to be close and then use that OAL reference to set back in .005" steps until I find the actual best shooting OAL. And even that isn't a specific spot, plus or minus nothing. Best OAL is a range, typically as wide as 10-15 thou for me. I strive to seat in the middle of what ever null exists and then slight variations in OAL, either real or to some measurement on the ogive doesn't matter, at least not in my rifles!
     
    Last edited: Nov 25, 2009
  9. woods

    woods Well-Known Member

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    I agree. I seat a normal cup and core or bonded bullet .025" off or a monolithic .050" off and by the time I have tried a couple of different bullets with a couple of different powders in ladder tests of 4 or 5 different powder charges, I have usually found a good load. That would make 2x2x4=16 different combinations minimum. It is all a matter of barrel timing anyway.

    Also, and I can't prove this, but I believe that any variation in seating depth will have a greater effect if you are seating close anyway. For example if you are trying to seat .005" off and for various reasons you have a variance of +-.003" then the ocassional one will be at .002" off or at .008" off and that will have a greater effect than if you were trying to seat at .030" off and had a few at .027" off or at .033" off. I either seat into the lands or at least .020" off and monitor seating depth with a comparator on each bullet.

    Need to watch bearing surface of the bullet also. The other day I was loading some 200 gr Accubonds and all of sudden had a big variance in seating depth. That prompted me to check the bullets and out of a dozen I checked there was a variance of .018". Now that was probably because I had mixed several boxes together but that prompted me to check more of my bullets.

    I found the following comparator readings on the bullets :

    .001" variation only with the 140 gr 6.5 SGK's
    .002" variance on the following bullets:
    130 gr 6.5 Scirrocco
    160 gr 7 mm Accubond
    150 gr 7 mm SGK
    180 gr 308 TTSX
    225 gr 338 Accubond
    225 gr 338 TTSX
    .018" variance on the 200 gr Accubond
    .021" variance on the 180 gr Accubond (probably also because of mixed boxes)

    There are so many factors that can influence OAL that trying to seat close to the lands is a tricky business IMO.
     
  10. Mike6158

    Mike6158 Well-Known Member

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    I tried something a little different the other day. I had determined distance to the lands in my Sendero with a Stoney Point tool, Sierra bullet, and calipers. I loaded a dummy bullet, used the mic gauge to get a baseline reading, and proceeded to load 6 at .010 off of the lands. Just for grins I loaded a round into the rifle by hand. It started giving me some resistance before being fully chambered. :cool: I extracted the round, seated my dummy round (basically an sized and un-primed case), "painted" the bullet ogive area with a black magic marker, and seated the round / closed the bolt. I extracted the round and looked at the ogive area of the bullet under my lighted magnifier. The lands had left marks in the magic marker ink at least 1/8" of an inch long. So much for using the Stoney Point correctly. I got at least 5 "good readings" so I'm not sure where I went wrong. When I checked the rounds that I loaded for my VTR they were fine and seemed to at least be off of the lands (your point about variances is well stated). Somehow I messed up with the Sendero (7mm Rem Mag). That said, I continued the black marker check, increasing seating depth .002, until I could see just a trace of land mark on the ogive. I called that "on the lands", mic'd the bullet, and backed up from there. I haven't shot them yet. That should happen on Friday.
     
  11. woods

    woods Well-Known Member

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    Hey Mike, that is mystifying. If your modified case had some headspace then the bullet should have been further from the lands on your loaded round, but if you are loading new cases and your ejector button pushes the case forward that could have been part of the problem.

    Hard to get all those moving parts and moving dimensions sorted out in my head. Perhaps your modified case was not seated fully, case shoulder to chamber shoulder. Tight necked custom chambers can cause that and I have had to outside neck turn a modified case to get it to work.

    What caliber?
     
  12. Mike6158

    Mike6158 Well-Known Member

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    I'm going to blame it on the operator... but I barely, and I do mean barely pushed the bullet in. If anything I expected it to be short not long.

    It's a 7mm Rem. Mag in a Sendero SFII. Factory rifle...
     
  13. mo

    mo Well-Known Member

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    Woods, Thanks for taking the time for your post and pics.
     
  14. bigbuck

    bigbuck Well-Known Member

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    Thanks for all the info fellas . I have a wyatt extended box mag and once I've installed it I'm going to try .010 off the lands and se if it helps any.

    Thanks

    Bigbuck