6.5 SLR/S Improved - Ready for testing

Discussion in 'Big Stuff -- 6.5mm, 7mm, 30 Cal' started by Rockfish Dave, Aug 5, 2013.

  1. 22BRGUY

    22BRGUY Silver $$ Contributor

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    Thanks for update Dave
     
  2. dennisinaz

    dennisinaz

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    Your expectation of 3000 fps with 140s is very optimistic to say the least. That is a 6.5-284 load.

    This sounds similar to my 260 AI and I get only about 2900 using even R17.
     
  3. Rockfish Dave

    Rockfish Dave

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    Actually what I said was: "With the full power fire formed loads I hope to get around 3,000 fps. I may be overly optimistic, but part of the fun is finding out."
     
  4. Raptor

    Raptor

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    My guess is you will be in the low to mid 2900fps range with 140s. Your brass will be the limiting factor for velocity. I have the 260IMP 30 degree and I started loosing primer pockets at the mid 2900fps. But you never know, hope yours will be a screamer!!
     
  5. Rockfish Dave

    Rockfish Dave

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    2,900 would make me a very happy camper!
     
  6. dennisinaz

    dennisinaz

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    Depending on your barrel length, I don't think you will get 2900 with H4350. You might have to find a different powder. There are two or three that will probably get there for you.
     
  7. Rockfish Dave

    Rockfish Dave

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    I base my hope for higher velocity on the 6mmar test results. My version has a little more case capacity so I should be able to do the same with a little less pressure... There is only one way to find out.

    http://6mmar.com/65_SuperLR.php
    Initial Chrono Results


    Below are some initial chrono results with the Sierra 142 gr Match King Bullets (that can be loaded magazine length to feed out of a short action magazine). Most of the 139-142 gr 6.5 mm bullets can be loaded at magazine length for magazine feeding and still remain close to the lands, but because of the long neck of the case, not have a lot of bearing surface of the bullet back in the case.

    42 gr H4350, BR-2 Primer, Sierra 142 gr. MatchKing - 2801 fps, E.S. 17, S.D. 6
    43 gr H4350, BR-2 Primer, Sierra 142 gr. MatchKing - 2885 fps, E.S. 11, S.D. 5 ****
    42 gr RL17, BR-2 Primer, Sierra 142 gr. MatchKing - 2836 fps, E.S. 26, S.D. 10
    43 gr RL17, BR-2 Primer, Sierra 142 gr. MatchKing - 2894 fps, E.S. 19, S.D. 6 ****
    38 gr Varget, BR-2 Primer, Sierra 142 gr. MatchKing - 2775 fps, E.S. 17, S.D. 7
    39 gr N150, BR-2 Primer, Sierra 142 gr. MatchKing - 2809 fps, E.S. 16, S.D. 6
    40 gr N150, BR-2 Primer, Sierra 142 gr. MatchKing - 2869 fps, E.S. 27, S.D. 10
    41 gr N150, BR-2 Primer, Sierra 142 gr. MatchKing - 2921 fps, E.S. 17, S.D. 6


    **** Note: The 43 gr. loadings for H4350 and RL17 shot well and did not appear to be top end loads. In further testing, loadings using 43.5 gr of H4350 and 43.5 gr. of RL 17 were used and shot well without any excess pressure signs noted (i.e meaning the 142 gr Sierra bullets were running 2900+ fps).
     
  8. 22BRGUY

    22BRGUY Silver $$ Contributor

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    Great info...please keep it coming Dave.
     
  9. JohnMill

    JohnMill Gold $$ Contributor

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    Yes indeed,Please keep it coming. Can we get a measured H2O capacity or did I miss it. I have the 6SLR
    Thanks John
     
  10. Rockfish Dave

    Rockfish Dave

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    Loading up rounds tonight in .2 grain increments up to the 43.6 gr. of H4350 tonight.

    I want to see where the pressure starts and if (when) I have a sticky bolt.

    So should I clean between each shot to have a consistent testing environment for each round?
     
  11. Rockfish Dave

    Rockfish Dave

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    I used a laser bore site to get it on paper and just started firing. The point of aim was about 2 inches above and to the left of the point of impact.

    H4350
    40.2gr
    139 Scenar
    br2
    [​IMG]
    [​IMG]

    Series 1 Shots: 6
    Min 2619 Max 2663
    Avg 2643 S-D 16
    ES 44

    Series Shot Speed
    1 1 2634 ft/sec
    1 2 2659 ft/sec
    1 3 2637 ft/sec
    1 4 2648 ft/sec
    1 5 2663 ft/sec
    1 6 2619 ft/sec
    ---- ---- ---- ----

    H4350
    40.4gr
    139 Scenar
    br2

    I forgot where I was aiming and ended up with 2 2 shot groups.
    [​IMG]
    [​IMG]
    40.4
    Series 2 Shots: 4
    Min 2639 Max 2665
    Avg 2649 S-D 11
    ES 26

    Series Shot Speed
    2 1 2665 ft/sec
    2 2 2646 ft/sec
    2 3 2649 ft/sec
    2 4 2639 ft/sec
    ---- ---- ---- ----



    H4350
    40.6gr
    139 Scenar
    br2
    [​IMG]
    [​IMG]
    40.6
    Series 3 Shots: 5
    Min 2651 Max 2701
    Avg 2684 S-D 19
    ES 50

    Series Shot Speed
    3 1 2701 ft/sec
    3 2 2689 ft/sec
    3 3 2693 ft/sec
    3 4 2689 ft/sec
    3 5 2651 ft/sec
    ---- ---- ---- ----


    H4350
    40.8gr
    139 Scenar
    br2
    [​IMG]
    [​IMG]
    40.8
    Series 4 Shots: 5
    Min 2639 Max 2721
    Avg 2686 S-D 32
    ES 82

    Series Shot Speed
    4 1 2714 ft/sec
    4 2 2721 ft/sec
    4 3 2676 ft/sec
    4 4 2683 ft/sec
    4 5 2639 ft/sec
    ---- ---- ---- ----

    H4350
    41.0gr
    139 Scenar
    br2
    [​IMG]
    [​IMG]
    (Forgot to chrono this last string).
     
  12. 22BRGUY

    22BRGUY Silver $$ Contributor

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    Looks like groups are opening up and on their way to re-closing IMHO. Will be interested to see at what velocity/pressure they tighten back up. Thanks again Dave.
     
  13. Rockfish Dave

    Rockfish Dave

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    I think the inconsistencies in formed rounds combined with cleaning the barrel after each string was contributing to the wonky velocity readings.

    That is why I attributed the accuracy to the barrel, it was not my loads. I also noticed that some of the loaded rounds were difficult to close the bolt on, but fell out with ease after firing leading me to think I may have more luck with consistent velocity spreads with the fire formed cases.

    I was trying to break the barrel in at the same time, to send it off for Melonite case hardening.

    I think I will do another few strings before sending off for treatment, because the max load/pressure data will change as soon as I have it treated.
     
  14. 22BRGUY

    22BRGUY Silver $$ Contributor

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    Read an article a couple of months back on meloniting and a fella mentioned that after having it done it never shot as well, but after several hundred rounds it finally seemed to get better....hope this won't be the case with you.
    Best Wishes
    Dennis
     
  15. Rockfish Dave

    Rockfish Dave

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    I have a little bit of experience (6 rifle barrels, 2 pistol barrels, 4 muzzle brakes, and one bolt and action) and have had zero issues. Two of the barrels were on rifles that I built and sold, unfired by me. The gunsmith made it such a miserable experience I didn't want anything to do with them after it was all said and done so I sold them below cost, so I cannot speak from first hand expirience on those, but the other 4 shoot just the same as before, just easier to clean. I didn't chronograph those so I cannot speak to velocities before and after.
    By doing multiple barrels at a time it's fairly cheap. I am pretty comfortable sending this in as well.

    It's worth it to me just for the ease of cleaning. It adds around 4-5% cost to the barrel so if the increase in accurate round count for barrel life needs to be fairly modest to pay for it's self.

    The 2 things to be sure to do:

    1) Use a minimum number of rounds to break in. Since my loads are very low pressure I'm not too concerned about this step.
    2) Clean the barrel like it is going to be used in surgery... before and after treatment.

    There is a risk with doing it, but the negatives have usually been tracked back to not adhering to the above, or soft steel.
     
  16. dennisinaz

    dennisinaz

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    I had three done at once, one whole rifle. I was quite disappointed in the way it all turned out. My Chanlynn barrel, which prior to melonite was shooting in the .2s and .3s suddenly started throwing fliers- I mean 3-4" out of the group. It would occasionally cause a bullet to not make it to the target- I think it was tearing the jackets up. This was at 3200 fps.

    I rebarreled with a Shilen and it went back to shooting like before for the most part. Shilen lapped my melonited barrel for me but I am not going to put it back on until I wear out the one I have on it.

    One barrel I left the muzzle brake screwed on about 2/3 of the way to protect the barrel threads. They didn't unthread it before treatement and it turned out real sloppy.

    The third barrel did not seem to take the finish properly and I was able to wipe all the black coloring off with a solvent soaked rag.

    The action that I had done is the only thing that seems to have turned out OK. I had to redrill all the pin holes etc as they came back packed with salts from the process. If I ever do it again, it won't be with the same place I used last time.
     
  17. Rockfish Dave

    Rockfish Dave

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    PM sent
     
  18. jfjohn77

    jfjohn77

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    Rockfish, How did this project work out for you? I'm curious about the 6.5 SLR.
     
  19. Concha

    Concha

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    I am shocked that the Surgeons firing pin is hitting that far of center.
     
  20. Rockfish Dave

    Rockfish Dave

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    Shouldn't be. It's kind of a result of fire forming to blow out the taper in the case. Fire forming of my 284 Shehane, and 375/338 Lapua Improved do the same. Those are on 1086R and Defiant deviant actions respectively. The 375/338 does it the least though.

    What should be shocking is the accuracy... surprised me. All of them hammer on fire forming. (all chambered in house by Bartlein) So fire forming loads just turn into my intermediate and hunting loads.

    I'll pick this project back up soon... I have the wildcat bug if you can't tell.
     

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