New Berger .224 Bullet

Discussion in 'Small Stuff--22s, 20s, and 17s' started by xswanted, Oct 5, 2019.

  1. Ned Ludd

    Ned Ludd Gold $$ Contributor

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    David - it goes around and comes around. I like the idea of helping someone else out if it's a topic I have any experience with. Many others have freely shared information here at Accurate Shooter that was helpful to me, so it all works out well. In fact, I just got back my original .223 Rem for shooting the 90s with a couple new barrel cut and am going to start woking up loads. If the 90s don't pan out for some reason, I may need to try the 85.5s.

    The 1% variance in OAL was what I was thinking about in the previous response about its effect on BC. If OAL variance has a direct and linear effect on BC, with a 1% OAL variance you're only talking about a change in BC in the 3rd decimal place. I would estimate that most of us would have difficulty in clearly distinguishing a change in BC of less than around 5% or so. A change equal or larger than that is fairly easy to discern using drop at 300 yd or farther. For bullets we typically use with G7 BCs in the .200 to .350 range, I would expect BC variance in the third decimal place for any Lot# to be the norm, from sources including dimensional variance, slight differences in the meplats, slight differences in the core, folds on the nose, and probably a few other sources I haven't even considered.

    Sorting bullets is all well and good; I do it myself by OAL as described above for pointing purposes. But there comes a point when the effort that goes into sorting by every parameter known to man is a waste as Monte alluded to above. Beyond a certain point, most people can't ever shoot the difference. Taken to the extreme, you could theoretically sort into sub-groups by enough different parameters that you'd end up with a single bullet in each sub-group. Not so good when you need 20 rounds plus sighters from the same sub-group for each match ;). I try to keep the sorting steps to a minimum, and select methods for sorting things that are relatively simple and fast (i.e. measuring with calipers, weight determination with a balance, etc.).
     
  2. barefooter56

    barefooter56

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    Garandman,
    There are many causes of bullet failure. Sometimes it may only be one issue. Sometimes it may be a combination of issues. Barrel length over 28 inches, bullet RPMs approaching or exceeding 300,000 , muzzle velocities approaching or exceeding 3400 FPS , minor defects in the barrel such as chipped lands , throat cracking , type of rifling, excessive twist rates carbon and copper build up, ETC . In short , anything that contributes to putting heat and friction on the bullet jacket of any cup and core bullet can cause its failure. Ned Ludd in one of his posts covers this very well also in regard to bullet design. Look at the ELR shooters that use 36 inch or so barrel lengths. Many of them have gone to solid copper bullets to help with these issues. Use the TWIST RATE CALCULATOR on the BERGER website to help you with your barrel twist rate choice. Base your choice on the lowest altitude you will be shooting at. The NATIONAL WEATHER SERVICE website can help you with this if you have the zip code of the area you are shooting at. It wont be exact . But it will get you close. 1.5 SG ( Stability factor) is a good place to be at 1000 yards. BUT ! If you are engaging targets at the extreme end of the range of cartridge/bullet combination you are using and need some more spin rate stability to help the bullet through its trans and subsonic stages of its flight . A little faster barrel twist rate may be in order. Check out Bryan Litz's APPLIED BALLISTIC LLC website education articles for more information on this.
     
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  3. garandman

    garandman Bolt Gun Bodacious Gold $$ Contributor

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    barefooter -

    Thanx!

    Barrel defects aside (i.e. assuming no barrel defects, to include carbon / copper deposits and wrong twist rate) ... from what I read above... the *main* cause of bullet failure will be "speed" - which can be driven by bbl length, and / or powder charge.

    RPMs / MV are mostly a function of the combined affect of "dwell time" (aka internal ballitics) and the powder charge pushing the bullet.

    Am I reading that right?
     
    Last edited: Oct 31, 2019
  4. XTR

    XTR Gold $$ Contributor

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    Not really correct takeaway

    Long barrels mean more heat from friction resulting in increased potential for melting the core.

    Higher velocity from longer barrels means higher spin rate for a given twist. Higher spin means greater force trying to pull the bullet apart. Based on internet reports there seems to be a threshold in the vicinity of 300,000 rpm that cup and core bullets fail.
     
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  5. garandman

    garandman Bolt Gun Bodacious Gold $$ Contributor

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    Right. The bullet speed in the barrel (i.e. interior ballistics) causing increased friction, heating, centrifugal forces, excessive RPM etc is still the *major* factor in jacket separation. Greater speed causes incrememtal increase in all those values, and therefore increased chance of bullet failure. What we're both saying is close enuf for me.
     
    Last edited: Oct 31, 2019
  6. Jdne5b

    Jdne5b Gold $$ Contributor

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    I've been running the 3 main heavy .224 bullets (88eld, 90vld, 95smk) between 330K and 345k RPM lately.. just because. I haven't had any failures in 1000 rounds, which I credit to running a .219 bore. If I wanted to build a large case .224 hotrod (Valk, BR, Creed, etc), I'd call Bartlein and order a 5R .219 bore in a 7 twist. If you shoot at sea level and don't feel like leaving any BC on the table, then get what nets you full BC but your failure chances increase. I personally would stay at a 7 for anything out there currently, but I don't shoot much at sea level in the winter. I also plan to run a .219 in all my future 223 FTR barrels.
     
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  7. CADDIE5

    CADDIE5

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    Anyone try Staball 6.5 with the new Berger 85.5gr hybrid bullets for f class rifle competition? Waiting for weather to warm up in Chicago area and premium unithroater kit to arrive. Thanks
    Steve
     
  8. Shootin25

    Shootin25 Silver $$ Contributor

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    Can’t find any locally... but did find 16 pounds of RL26 yesterday! LOL
     
  9. garandman

    garandman Bolt Gun Bodacious Gold $$ Contributor

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    I've loaded up a bunch of 80.5 & 85.5 Bergers, both testing seating depth and a "ladder test" of incremental powder charges.

    Berger recommended testing seating depth first, starting at the lands with the 80.5s and 15 off with the 85.5s.

    For my 224Valkyrie. Will pull trigger this Monday.
     
    Last edited: Nov 2, 2019
  10. Shootin25

    Shootin25 Silver $$ Contributor

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    Ran these up to 3213fps in a 6.5 twist 23.5” barrel. Speeds were consistent but couldn’t get them to group. What I didn’t do was test different jump dimensions. Everything was loaded at 20 off, and average groups thru all speeds was .75 @ 100.
     
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  11. garandman

    garandman Bolt Gun Bodacious Gold $$ Contributor

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    Sesting Depth Test # 2 -

    20191109_160012.jpg 20191109_155918.jpg
     
  12. milanuk

    milanuk Gold $$ Contributor

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    Well, got a couple MR matches under my belt with this combination.


    The short version... it shoots. At least as well as I can hold, probably better. It'll probably take a better shooter than I to really wring this out properly.


    Unfortunately, my 'history' with the .223 Rem in FTR is that it seems to 'punish' me for gun handling that I would otherwise 'get away with' using a .308 Win. So a lot of the 'stray' shots are all me, for one reason or another.


    Saturday, Nov. 2nd 600yds @ NCWGC (East Wenatchee): winds were light and variable - no visible mirage, flags moving just enough to show there was *something* going on. Downwind shots were the wind; vertical... bad gun handling.


    Relay #1
    monte1.png

    Relay #2
    monte2.png

    Relay #3
    monte3.png

    Then again today on November 9th, 500yds @ Machias. Conditions looked dead calm, and pretty much were for the first string. Second string, definitely had some push from the right, and third string had more of the same, plus some vertical movement going on down range. FWIW, this was actually three different loads being tested: 24 gn N150 w/ normal (3 thou) NT, with lighter (1.5 thou) NT, and then 23.9 gn. The original 'control' load actually shot the best, in my opinion... little bit of 'me' going on in the middle of the first half, and then had one round that chambered funny (had to force the bolt closed). Debated whether to extract and use a 'spare' round, but was concerned that I'd end up with a stuck bullet and/or powder everywhere, so I opted to send it - straight down @ 6 o'clock, as it turned out >8{(}

    Otherwise the control load shot pretty well The lighter NT load... was 'all over' the place, relatively speaking, and the two leakers were very much not on call. The last string was actually clean, but I had to work my behind off for that one - it felt 'looser' on target than the first load, for whatever that's worth.


    Relay #1 (24.0 gn N150, 3 thou NT, control load)
    2019-11-09_milanuk1.png

    Relay #2 (24.0 gn N150, ~1.5 thou NT)
    2019-11-09_milanuk2.png
     
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  13. milanuk

    milanuk Gold $$ Contributor

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    Relay #3 (23.9 gn N150, 3 thou NT)
    2019-11-09_milanuk3.png

    Also... not sure quite what to make of it, but the same charge seems to have sped up a noticeable amount from before. Whereas 23.9-24.0 gn was clocking @ 2780-2790 fps @ ~30-35F during load testing, the same charge weights are now running more like 2830 fps, based on 1) my LabRadar on Friday, and someone else's set up today on our firing point.


    Either this lot of N150 (8.1.2014) isn't as temperature stable as I thought, or this barrel (Krieger) took an insanely long time (>400 rds) to 'speed up'. Definitely 'odd'...
     
  14. garandman

    garandman Bolt Gun Bodacious Gold $$ Contributor

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    In that case... can ya just send the round into the berm ?
     
  15. milanuk

    milanuk Gold $$ Contributor

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    Ah... sure. If you want to drop 10 pts instead of 1 pt... o_O
     
  16. MikeMcCasland

    MikeMcCasland Gold $$ Contributor

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    Nice shooting! I bet you puckered pretty good when shot 8 on Relay 3 came back on the shotmarker. ;)
     
  17. garandman

    garandman Bolt Gun Bodacious Gold $$ Contributor

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    So you have a limited # of rounds? Once you chamber a round, it hasta be fired for score?
     
  18. milanuk

    milanuk Gold $$ Contributor

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    Once you are in record shots, yes. Some matches (or strings that make up a larger match) may have 'unlimited' sighters, where you can take as many as you want... but still, once you go for record, they *all* count. No going back to sighters to check the conditions, like in (for example) short range score benchrest aka Hunter BR or Varmint-For-Score.
     
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  19. milanuk

    milanuk Gold $$ Contributor

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    You sure as heck didn't hear me wanting to go down and measure the hole vs. the line... ;)

    That particular load was an attempt to see if the speed would drop back down a smidge to where it'd tuned in at earlier (~2800 fps).
     
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  20. CADDIE5

    CADDIE5

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    Excellent shooting, congrats. Thank you for posting targets and load data.
     
    Last edited: Nov 10, 2019

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