New Sendero troubles

Discussion in 'Long Range Hunting & Shooting' started by WV Sendero, Jan 31, 2011.

  1. WV Sendero

    WV Sendero Well-Known Member

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    I just bought a new Sendero 7mm mag about a month ago. I now have 150 rounds through it and have not found a load that will shoot better than 1". I have tried three different bullets and five powders. I'm not sure what is causing my problems. I am finding brass shavings on the bolt face and the base of the cases are somewhat scarred up. The brass is Norma so it is not just cheap brass. Some cases are hard to work in the action especially after neck sizing (I'm not shooting hot loads and there a absolutely no pressure signs). None of the fired cases are hard to eject though. I also had some dummy snap caps to practice with and try the trigger after adjustments and the gun also scarred up these cases around the base. If anyone has any idea what the problem is and what my options are please let me know.
     
  2. rscott5028

    rscott5028 Well-Known Member

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    Have you tried any factory premium ammo?

    Have you had good success with thes dies on other rifles? (Bad dies)

    Have you been able to measure concentricity, headspace, COAL?

    Norma is the best I've found for 7mm Rem Mag.

    Do you also use other premium components?
     
  3. WV Sendero

    WV Sendero Well-Known Member

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    I haven't shot any factory ammo in it at all mostly because I need to make it shoot reloads. I haven't used the dies on other rifles because it is my only 7mm but the FL sizer and seater dies are the RCBS competition dies and the neck sizer is the regular RCBS. As far as other components I have used Norma brass, Amaxs, VLDs, and Matchkings. Primers were Fed LR match, and WLRMag. Powders were Retumbo, RL22, H4350, IMR 4350, H1000. Nothing I use is junk stuff which is why I can't figure out whats going on. The scope is a Mark 4 8.5-25 and the rings and base are also Mark 4. The thing that concerns me the most is the brass shavings on the bolt face and the scarring on the base of the brass (it also did this with the dummy rounds).
     
  4. retiredcpo

    retiredcpo Well-Known Member

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    I tried several bullet powder combos in mine and ended up with
    H4831SC for both 160 accubonds and and the 168 bergers
    now Im working on 120 vmax which 4350 shot one hole at 100 yards
    so Im going to play with that alittle and try N165 on friday
    I could not get the amax to shot and did not try the matchkings
    All my brass in winchester and I use WLRM primers.
    One thing look in the bolt face there is a rivit like thing near the extractor
    a budy bought a remington cdl and it was not flush like it should be
    had to send it back to remington to fix it
    good luck
    Retiredcpo
     
  5. rscott5028

    rscott5028 Well-Known Member

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    Perhaps someone else can address the brass shavings on the bolt face...

    In most cases, I see that with heavy loads. But, it could be accentuated by too much bolt thrust due to a slick chamber. If neither of those, then something is scoring the brass. And, it may or may not have much to do with your groups.

    Check the fololowig:
    - you already addressed the scope mounts/bases
    - barrel is floated (nothing touching i.e. fingers, sling stud)
    - action screws torqued correctly
    - proper cleaning techniques (e.g. carbon fiber rod, bore guide)
    - if it has a brake, try without the brake
    - try a box of premium factory ammo

    You sound like you've got experience. But, I'm amazed at how many variations you've tried. I'd step back and start with the basics.

    It sounds like you only use quality components. So, I would focus on Norma Brass, RL22, GM215M primers, and 168 Bergers. (that combo works for me. or, pick a combination that's worked for others) Vary only the powder charge and, work up from min load to max with the ogive right at the lands using 2 shots each at half grain increments.

    Pick the best 2 shot group surrounded by a couple of good groups that are also of similar elevation. In other words, some range of powder charge that seems stable.

    Then, load/shoot 3 rounds at different seating depths holding the powder charge constant and adding .040" seating depths until you get to > .100.

    Pick the best group, and load that group shooting 2 groups of 5 shots.

    Now, start refining the powder charge +/- half grain in smaller steps again.

    The objective is to change only one variable at a time and keep fine tuning.

    There are a number of other methods. but, it sounds like you got frustrated along the way and started trying too many different components.

    Hope something here helps!
     
  6. WV Sendero

    WV Sendero Well-Known Member

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    First thanks for your suggestions. I actually already did everything you suggested (torque, carbon fiber rod, guide, checked mounts, barrel is floated) minus the factory ammo. I hope you're right about just getting in too big of a hurry. I'm just annoyed because I'm trying to be meticulous about everything and I am not getting what I expect. I tried the seating at different depths and it seemed to do the best right at the lands. Retumbo and Amaxs did the best so I guess I will go back to them and try to refine those loads like you suggested. I am the most concerned about the brass problem because it did it on dummy rounds, and new empty brass. It just scars the brass right on the rim of the base like it is the extractor or something. If it is the extractor doing this is it likely that it would cause accuracy problems or simply just give me the brass shavings?
     
    Last edited: Jan 31, 2011
  7. retiredcpo

    retiredcpo Well-Known Member

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    Again
    Inspect the bolt face
    my buddies remington was doing the same thing on the lip near the extractor
    is a rivit looking thing it should be flush his was not and was scaring up the brass and interfering with ejection shells
    It had to be fixed my remington but now it shoots great
    retiredcpo
     
  8. rscott5028

    rscott5028 Well-Known Member

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    I took a closer look at Sendero and don't see the rivit thingy that retiredcpo mentions. So, mine doesn't have one or it's completely flush unlike the ejector pin which is spring loaded.

    However, the extractor is sharp and, does shave tiny flakes off the brass from my cases. I never noticed it before as being the cause. I just brush the bolt face as part of my cleaning process.

    If it's off quite a bit, it could be damaging your brass and may need to be filed a tiny bit. But, it's likely not the cause of not being able to get to sub-MOA.

    Remove the bolt and make sure you can slip a fired case into the bolt face. If it doesn't make it over the lip then you probably need to see a smith or return it to Remington.

    As far as losing a little brass from the case head goes, I frequently notch my case heads anyway with a file to index them so as to align the thick wall of the brass with the bolt lug at 12 o'clock. I don't know if it really helps. But, it doesn't hurt anything.
     
  9. Topshot

    Topshot Well-Known Member

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    Perhaps someone else can address the brass shavings on the bolt face...

    Don't worry about the shavings, they are just a minor problem with the extractor clip.
    I would be more worried about the accuracy of that rifle. I had a Remington 7mmRM last year and it had a faulty chamber.
    The chamber was that badly cut that I could not extract factory loads after firing. The problem was with a deep bur in the chamber.

    The smith that rebarreled it for me said that Remington had a bad batch of 7mmRM chambers cut.
     
  10. WV Sendero

    WV Sendero Well-Known Member

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    I think that part on mine is ok. It may be something with the extractor itself. The shells eject fine though so I'm not sure whats going on. I'm going to shoot it some more and if nothing changes for the better I think I will send it to a gunsmith see what they think and have the action blueprinted at the same time. I want to get it straightened out soon though because I don't want my gun at the smith when the weather warms up. Thanks for the advice by the way.
     
  11. johnnyk

    johnnyk Well-Known Member

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    Have you full length sized your brass at any time? I didn't see that mentioned in any of the above threads. A FL resized case should easily chamber after this with no shavings apparent. A "brass ring" on the bolt face is normal, but brass shavings is not.
    The Remington factory extractor is riveted in place. The rivet is ground off to be flush and should not snag on anything. I had mine of my first Sendero break (after years of faithful service) and had it replaced with the Sako style and they work great also.
    What weight bullets are you trying? I tried the 168gn Bergers in my 700P and they never would shoot but it loved the 150gn Ballistic Tip. Shoots those in to one hole with IMR4350 and IMR4831. JohnnyK.
     
  12. meatyrem

    meatyrem Well-Known Member

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    I would think that if the bolt face/extractor ex. is not quite as true , that it may bind it up just enough as to impart torque on the case and therefor cause accuracy issues. I had very tiny brass shavings on a brand new 700 that before I fired it, I had ran a couple of rounds through it to check out the cycling. Now , I can expect some of that, but how much are we talking, a considerable amount? There may be some abrasive burrs on the bolt face. Probably need smoothing. Another thing, check your lugs on the bolt, check to see if the wear marks on both lugs are even and run all the way length wise across the lugs, if you only have one lug with a wear mark and little or no wear marks on the other, you may need it trued by a smith. Just my thoughts. Good luck.
     
  13. Kevin Cram

    Kevin Cram <b>SPONSOR</b>

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    Has anything been done to rifle to help accurize it. There could be several things working against you. The crown could be cut out out of alignment from the bore. Not to uncommon to see from the factory. There could also be scratch of ding in the crown effecting accuracy. If the action is not stress free bedded and the barrel 100% free floated it should be for best accuracy potential. Are the bolt lugs lapped? Are the scope bases stress free and loc-tited in place. Are the scope rings lapped and the scope sitting stress free with the reticle aligned? It sounds like you have a good grasp on reloading so to me it sounds like the rifle just needs a good tweaking to make it work a little better towards its potential. As far as the brass shaving in the bot face I see this alot with factory Remington extractors. There are a couple of things that cause this. The factory extractor groove may not be cut deep enough for the extractor to properly expand in far enough to snap over the rim of the case. If it bottom out the brass is softer than the extractor and it will just tear a groove in the rim. The factory extractor is a pretty stiff, add along a sharp edge and brass shavings is what you get. Your probably noticing when you push the bolt forward you have to give it a little extra uugghh to snap the extractor over the rim of the case. It's not a accuracy deal breaker other than it's a pain in the ass. A sako extractor has a more positive extraction and you won't have to grunt to snap the sako extractor over the rim, you probably won't even feel it snap over. I'd be glad to talk with you about accurizing your rifle and a sako extractor, if your interested feel free to give me a call, my numbers on my website.
     
  14. RDM416

    RDM416 Well-Known Member

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    Just to start off, I'm going to say "Don't take this wrong.... I'm not knocking your rifle"!!

    I think from what you have tried with your handloads that it might be time look elsewhere. I know many people have had better results with a factory sendero, but 1 moa is pretty good for most factory rifles, including a sendero. It might be time to send the rifle to Kevin Cram, who posted the previous reply or another smith and have them check the rifle out for anything simple that they could take care of without the full blown treatment, of truing the receiver, and new barrel. Regardless of how good you handload, expecting to pull a factory rifle out of the box and have it shoot under 1 moa is a tall order in my experience.

    A couple of quick questions.... Have you bedded the stock? I have a 300 RUM sendero that I picked up several years ago that did not shoot very well. I bedded the stock and used the tubb final finish bore lapping process on it. (first and only time I have used the fire bore lapping process) I don't know if the lapping helped or if it was just the fact you fire 50 rounds which may have finished breaking in the barrel. After the lapping and bedding the rifle will shoot 1 moa maybe a little under. I am not recommending or knocking the Tubb fire lapping...... don't really know if it works or not. On that rifle I just figured I had nothing to lose as my next step was to have a new barrel installed (which I still need to do..... she is just a just a gun safe queen that never get used right now).

    Back on your handloading..... Do you measure runout with your loads, what are you seeing if you are?? Are you loading to fit the magazine?