338 Lapua, hard to chamber

Discussion in 'Reloading' started by SAPPER26, Jul 30, 2012.

  1. SAPPER26

    SAPPER26 Well-Known Member

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    I have a custom 338 Lapua Magnum that I have put just over a hundred rounds down range. I bought 100 rounds of Lapua brass and selected 50 to do initial load development. I found a the load of 92gr H1000, Fed 215M primer, 300 gr Berger .015" off the lands to hold less than 1/2 MOA with no pressure signs. This load worked well until I bought a new lot of powder and started to notice a stiff bolt lift after firing. I figured this had something to do with newer lots of powder burning hotter. The bolt lift wasn't too bad, but still was stiff so I bought an 8lb jug and decided to redevelop a load. I have no chrono results, but am getting a new one soon. I started at 88 grains and worked up to 90 grains, however, every round had the same stiff bolt lift. This didn't seem right to me so after I FL sized the brass with a Forester benchrest sizer, I decided to run one in the gun. After being sized it gives me the same stiff bolt lift as if it were fired. New brass has no issue. I bump the headspace back .002" when resizing. I even bumped the headspace back to what the new brass is, which was approx .004" and it still has a stiff bolt lift. The only time I had a stiff bolt was with once fired,resized brass. The last 10 rounds were on their third firing and these have had the stiffest bolt lift yet, with a reduced load of 90 grains.

    Inspecting the brass further, about a half inch above the extraction grove it measures .005" wider than factory new brass. I marked a case with a sharpie. When I chambered it, it showed a rub mark at this same area. Obviously it is contacting there.

    My question, is my sizing die not sizing the cases enough? The only real resitance I feel is the mandrel going through the neck. The other possibilty I've been told is that I might have an oversized chamber. Has anyone had anything like this happen to them? I would appreciate any ideas. Thanks.
     
  2. J E Custom

    J E Custom Well-Known Member

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    Double post.

    Sorry.
     

  3. J E Custom

    J E Custom Well-Known Member

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    If you have a oversize/larger chamber, the sizing dies should take care of that. It,s the tight
    chambers that sometimes dont get sized enough because the dies are not small enough.

    I would look at the neck diameter, case length compared to chamber length and bullet
    seating depth.

    Anyone of these can cause pressure even with reduced loads.

    If the case necks are nor releasing the bullet enough, You will have pressure.

    If the case length is longer than the chamber, they tend to crimp and cause pressure. (A simple test
    is to try to stick a bullet in a fired case), if it does not want to go the case needs to be trimed.

    If your bullet is touching the lands or very close this can also cause Pressure in full house loads.

    Just a few things to look at.

    Hope this helps.

    J E CUSTOM
     
  4. Tikkamike

    Tikkamike Well-Known Member

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    Sounds to me like you are not sizing them enough, I have no experience with forester dies though. they may have been over pressured and the head expanded too much, but I dont think so. my loads in my 338lm are very hot but I have not had a problem and I am on my 7th load with this lot of brass.... My guess is you dont have your dies set up properly, it happens.
     
  5. SAPPER26

    SAPPER26 Well-Known Member

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    J E,

    The neck is tight, but a bullet will slide into the neck on a fired unsized case. I was thinking maybe the cases were too long, but I trimmed them down to the factory brass length that was chambering fine. Next time I load, I will back the bullet off the lands more to see if that helps. I would think the die would resize the case if it expanded in an oversized chamber also. That's why I think maybe the Forester isn't sizing it enough. I ordered and Redding S type bushing neck sizer and a redding body die to see if these will do the trick.

    Tikkamike,

    I'm bumping the headspace back .002 when I resize it, even more when I tried to match the factory new brass. There is no way I can size it more since I'm already camming over a good bit to get it back to the factory headspacing measurements. I could try a different shell holder, but I don't think its a headspace issue. The body just isn't getting squeezed back enough.

    There are no other pressure signs on the case. Primers look good, no extractor marks. Has anyone had a die that hasn't sized enough?
     
  6. Tikkamike

    Tikkamike Well-Known Member

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    I have a redding bushing die set with a body die, if you send me a couple I could run them in there maybe its your dies? I guess it would eliminate that from the equation
     
  7. Broz

    Broz Well-Known Member

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    Snapper26, As we talked before, the reason I suggested the posibility of an oversized chamber was this. I once picked up a couple once fired (Lapua) 338 LM cases used. When sizing these cases in my Redding body die they almost stuck. More lube was needed as they were tight above the rim about 3/8 to 1/2". Same as yours. Checking with the mic. proved these cases to be swelled about .005" in this area. Even after sizing a couple times and moving the shoulder back they would not chamber in my rifle. So sizing dies will not always size enough if the case is out too far. After working with these a while I tossed them away and wrote it off. I figured the rifle they had been fired in had a larger chamber than mine. I should also note that these cases didn't show much other sign of over pressure. Only the swell and a shadow of an ejector pin mark. This I have seen before and even with my rifle on a hot day. But the brass still sized perfectly and the brass is still in use. I have loaded extensively for the 338 LM with several powders and bullets. My current load is slightly above your accuracy load with H-1000 and also seated -.015" off the lands with a 300 Berger. Since you stated that you feel the resistance on close and lift of the bolt of a freshly sized case I feel it boils down to things. A chamber that s a little large or a die not sizing enough. I will be interested to see if the redding body die cures the problem. I do not feel you are over pressure, especially at the reduced test load of 88 gr.

    Make sure you lube the tight area of the case well with your new die. If it is indeed doing more work a little extra lube will be a good thing.

    Also, I set my Redding body die up to fully camover. Then I use the Reddig stepped shell holders to adjust the amount of shoulder bump. (.0015 ~.002")
    This was recommended by Redding Tech and works great.

    Jeff
     
  8. Greyfox

    Greyfox Well-Known Member

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    I just went through the same thing with my 260 Reminton. Initially I loaded 44gr.of H4831sc and had no problems using my FL sizing dye. I tried working up loads using some VLD's up to 46 gr. There were no pressure signs but no matter what I tried which included three different FL dyes, the cases were expanded near the base and would stick in the chamber. When I went back to my brass that wasn't overpressured , or new brass with my original 44gr.grain load I had no problems. Once the Lapua brass was over pressured, nothing would bring it back. Even overcamming excessively. It's possible that your new lot of H1000 was hotter than your original. I just had this issue with both H1000 and Retumbo and had to recalibrate my 6.5x 284 loads 2 gr. lower to get my original velocities. It is possible that the 92 gr. load you used with the new lot, which is pretty hot even with the older lots of powder, may have expanded your brass beyond resizing. You might try backing off a few grains using new brass and see if you still have the brass sticking. I don't know if this is the issue, but the fact that you didn't have any problems until you changed powder lots leads me to believe this should be looked at first. iMHO.
     
  9. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Another thing to look at is how fat the case gets just above the web. If it's anything like a 7rum I had, the dang brass will be fatter than the max. spec. drawings. If so, you'll have to have your barrel set back a couple of turns and your chamber re-cut. I gave my rum back to the store because Rem wouldn't touch it. The brass from that rifle zipped open two perfectly good fl sizing dies( a redding and a rcbs) and they still wouldn't do anything(the dies looked like they were hit with a log splitter). It miked at .555" instead of the nominal max of .550".
     
  10. SAPPER26

    SAPPER26 Well-Known Member

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    I appreciate everyone's help. Once I got home tonight it was back to the shop to troubleshoot more. I pulled out the decapping assembly to see exactly where the case will be sized in my Forester FL sizing die. The only thing that was sized or touched the die was the neck. The body wasn't touched. I looked at some specs for the Lapua in a Lyman reloading manual for maximum measurements.

    .............................................Fired Brass. New Brass... Lyman book

    Rim _____________________.584"___ .5835"_____ .588"
    above extractor grove ______.584" ___.5835"_____ .587"
    shoulder _________________.546" ___.542" ______.544"
    Half way up the case _______.567"___ .563"________ N/A

    What I noticed is all measurements are below what is listed in the book besides the shoulder measurment. Another difference is the middle of the case where there is on average a .004" increase in size. The book doesn't have a measuremnt for this. It varies due to the case taper, but I measeured at the same spot on each case. Also, when I put to cases together so the bodies are pressed together, you can see light at the ends and notice the middle of the body is the contact point. Not sure if this is normal.

    What I am thinking is the chamber is somewhat tight, or the sizing die is way too big. Measuring the inside of the die where the last part contacts the die, measures .588" , .004" larger than the fired brass. The issue in the chamber must be the middle of the body which reinforces the sharpie test. Hope this clarifies it some.

    Jeff,

    I will try your shell holder trick. Hopefully the changing of dies will be the key. I should have them here in a couple days.
     
    Last edited: Jul 30, 2012
  11. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Any measurement above book numbers is excessive. The numbers Lyman lists are max. I have the Lymanbook too. I'd like to know what your measurement is right above the web where it starts to swell when fired. If that is above Lyman's .587" number, you have a fat chamber and it either needs work, or you are going to have to find dies that will work with it. As I stated in the earlier post, .005" over book numbers was enough to break dies.
     
  12. SAPPER26

    SAPPER26 Well-Known Member

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    Lefty,

    I'm not sure what you mean by the web. I think you're talking about the area just above the extractor groove (toward neck) where it starts to taper. It measeared .584" which is .003" less than maximum and essentially the same as the unfired brass. The measurement at the shoulder is .002" larger than what the lyman book suggests, however, when I sharpied that area, it didn't show any rub areas there.
     
  13. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    Right above the solid head of the case where it swells when fired is where I'm talking about. Look at the case drawing on page 45 of the lyman book(#49) for what I mean for web. That should be your largest measurement for girth on a tapered round and if it is over-book numbers(.587") your chamber is too big and either needs work or you'll have to find dies to work with it to get your sized #'s .002" or so under fired #'s.
    As I said earlier, I had a 7rum with somewhat similar issues, the rifle acted like I wasn't really sizing brass, brass was over dimension, splitting fl dies, etc.. I should have re-barreled or re-chambered, but I threw in the towel and got my money back. I still wish I had that action, as mag. lefty actions are hard to get at times.
     
  14. J E Custom

    J E Custom Well-Known Member

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    It looks like you have a tighter than normal chamber, caused by a worn reamer.

    The body taper should be straight (No bulges). this will make extraction difficult.

    I would find a good smith and have him touch the chamber with a good/new reamer
    and reset the headspace.

    Factory ammo is sized to small base diameters to feed in any chamber, so unless you have
    a set of small base dies, you can't size them. You could buy a set of Hornady New dimension
    dies that can be adjusted down to small base dimensions, but you would still have a bulge in
    the chamber that would give you problems.

    I would just go ahead and have the chamber set back and head spaced. If you are not sure of
    the condition of the smiths reamer buy a new one for your self, let the smith use it,and keep it
    for later use or sell it to someone on this site.

    This is one reason I don't rent reamers. (I don't know there history and how many times they
    have been used. A new reamer is a very small part of the cost of a custom build and it is not
    the place to save money.

    In the order of importance for a quality,custom build You have to start with ;
    1 = a quality barrel
    2 = a quality chamber reamer.
    3 = quality gunsmith to accuratly machine and assemble all of the componants.
    4 = a quality stock properly bedded and floated.
    5 = load quality ammo.

    The best componants available can't make up for any of these things if one or more is left out.

    J E CUSTOM