My accuracy jump with simple primer change

Discussion in 'Reloading' started by diderr, Sep 6, 2012.

  1. diderr

    diderr Well-Known Member

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    I decided to buy some BR-2's today and see if I could get my gun shooting more accurately. I was surprised to find quite a good jump in accuracy. I cant wait to try it at 1,000 yards. The left is the br-2 the right is 9 1/2m remingtons. 0.073 vs 0.233 minus the cold bore shot. it's a 300 wsm with 210 bergers with h4831sc at 100 yards .
    [​IMG]
     
    Last edited: Sep 6, 2012
  2. T3-OleMan

    T3-OleMan Well-Known Member

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    Please tell me about what you learned about the "cold bore shot'.
    That is the one I am after. Did you see changes there also, and what kind of cleaning process do you use.
    Good shooting!
     

  3. diderr

    diderr Well-Known Member

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    Well my second group didn't have a fouling shot because it was shot from a warm and dirty gun. The first group (r.) was shot from a cold, semi-clean gun that hasn't been shot in a few months. It could have been more of a "cold shooter" vs a "cold bore"
    I just clean my gun like any normal American. Hoppes, dry patches, and run a patch of Rem oil down it. I only clean the barrel every 80-100 rounds or so.
     
  4. T3-OleMan

    T3-OleMan Well-Known Member

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    Thanks, it may help me with my attempt to get my 225gr MRX hand loads to do some what better when I go back to them next year. I was cleaning after every shot like a Blackwater dude showed me he did to his 308. My 338WM likes dirty and only 185gr GMX is available in factory ammo. Got all the parts now to dupe that round also and might try those BR-2s as the primer instead of my GM 215Ms that are the only ones I have tried. Thanks again, next year I'll try the clean cold trick with those BR-2s on the 225MRX and 185GMXs. Pls send me a message if you learn more on that part that I am interested in-clean cold - one shot - one kill!:D
     
  5. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    The left hand target is likely a screamer group, and will be rather hard to re-shoot repeatedly. I've seen rifle pop .2" or less one day with a load, the next day they are at .3" to .5" with said load, if not worse. I'n not sayin' it's not good, it damn well is, but you've got to dump a few groups to get an average before you know the new primer is better.
    Almost every rifle I've got has put down at least a few screamer groups. The only one I could consistantly get cloverleafs with was my sendero 7stw. The new lh one shows promise, but it's still hovering at .5 moa.

    t-3 have you worked with rl 19 in your 338? My 338 loves it. Both 225's and 250's.
     
  6. diderr

    diderr Well-Known Member

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    What powder do you use? What I've read is the br-2's work better with slower powder. I use 65 grns of H4831sc and it ignites really well. It's not as much flame as a 9 1/2 m or a 215 of course , but as long as it lights well.
     
  7. Greyfox

    Greyfox Well-Known Member

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    I have found similiar changes in accuracy when changing primers but have not been able to establish any hard guidelines between brands except for CCI and Federal magnum primers generally produce better results with accuracy, and ES with large case capacity cartridges using slow burning powders. I find myself changing primers when I'm trying to tighten my ES more than improving accuracy and have had positive results.
     
  8. T3-OleMan

    T3-OleMan Well-Known Member

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    A)
    B)

    Details: Goal in Dec 2008 after Bull of a life time got up 4:37pm and walked off from 50 yds below me - cause I did not shoot a dead bull {NOT} between the shoulder blades before I went around the mt top to call for horse help for next morning-thank GOD my 15yr old cell would not lock on to town 35 mi. away even though I could see town and hear it dialing (don't get me started-LOL)-REPLACE .270 mod 70 _3,100fps+ (after 45 yrs._140 Black Talons last 15yrs.) with CANNON - 6.6lb Tika T-3 SS lite-no brake-338WM 225gr MRX @ 3,000fps on H4350 and GM 215M in WW brass-cleaning after each shot so all shots are 'clean cold'!! Never got Nellie to do her part on the 'clean cold' part....grouped fine....put a new Victory Davari on Dec 2010 and when I was Zeroing it in found out she liked the store bought Horney 185 gr GMX Superformance in dirty mode(>15 rounds). right now I'm ELK hunting dirty with the 3,080fps 185gr GMXs to 800yds. I would still like to get back on my original plan which is same as Broz does...clean to the shine and nail it when 'clean & cold'. When you get to a clean bore you can dupe that every time...I can't be sure I can dupe a perfect shot if it comes some where between 15 and 40 dirty shots. I just ain't that good!

    A) I bought a bunch of powder flavors when I started in Dec 2008 that might work in my gun and since I ELK hunt at 10,000' in -5F > 60F I needed most stable non temp-sensitive powder and H4350 is what I concluded would meet that reqirement. I do have all the RLs that might work and a bunch of other sample cans but purchased all the components for duping the GMX 185 since I have 5 boxes of fireformed Horney brass now. I know my Superformance powder is not the same as Factory rounds.....IT WILL BE CLOSE ENOUGH THOU! What I don't have is the Horney primer and thought I would try your trick (BR-2) on my one MRX 225gr load and when I develop the GMX 185 load. I will get back to it next year IF~N I live long enough. It's a 3 hour trip to go shoot and BARRY O ain't put nothing in my SS check since he got here, so I don't have to ever do it. Those GMX 185s don't kick any more than my old .270 did with it's plastic butt pad!!!!:D

    B) I have the H4831 & H4831sc and hope to test in JAN to try and get bullseye with my 'clean & cold' then I can dupe it every time. Please send me some info. if you learn anything that might help me and my one shot desire....not grouping. Thanks again.
     
  9. lloydsmale

    lloydsmale Well-Known Member

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    heres what ive found with primers. Yes they can make a big differnce in accuracy. Ive seen groups cut in half by changing primers. Is one any better then another. NOPE and ill even include various match primers in that statement. Ive seen better accuracy by changing primers but bump that powder charge up or down a grain or switch to a differnt bullet and everything changes again and your original primer might be the one that shines.
     
  10. diderr

    diderr Well-Known Member

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    THis what the load on the left did today at 400 yards with a VERY heavy mirage off a bipod and a rear bag. 1.371" or 0.327 MOA
    [​IMG]
     
  11. T3-OleMan

    T3-OleMan Well-Known Member

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    Critters be scared.....be very very skeeeerrrrredd. :)

    Close enough for Gov work....ie Wolfs control.:D
     
  12. lloydsmale

    lloydsmale Well-Known Member

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    thats as shootin sob!!
     
  13. diderr

    diderr Well-Known Member

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    I want to try it again on a different day to see if I can get it even better without a mirage.