243 load H4350 with nosler bt 90 help

Discussion in 'Reloading Forum (All Calibers)' started by Coyote243, Feb 26, 2020.

  1. Coyote243

    Coyote243

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    I’m new to this page so bear with me .. I’m working on a load for mi .243 win. I have my brass trimmed 2.040 and was wounding about seating depth .. nosler book calling for 2.680 Hornady 2.640 Hodgdon 2.625 and I have no issues with them seating at 2.690 I check to see where they hit my landing and it’s over the SAMII witch is 2.710 and advice will I be ok to work up a load with OACL @2.690 or should I back it down ?
     
  2. Ralph Littlefield

    Ralph Littlefield

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    The things to think about when seating bullets are will it fit my magazine. This is mostly an issue if the rifle is to be used hunting.

    Next is accuracy. Each rifle is unique, and you will have to test to determine what is best for you.

    Also safety can be an issue. If you decide to load a bullet so it is jammed into the lands, work it up slowly because jamming a load can cause serious pressure spikes.
     
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  3. Coyote243

    Coyote243

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    In regards of fitting I’ve checked that they fit and made sure they chamber with ease as for the landing I’d have to set over the magazine so wouldn’t worked and safety bus what I’m mainly concerned with being so different from book to book
     
  4. Zero333

    Zero333

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    Seat them as long as possible with out going into the lands and still be able to feed from the magazine.

    The 90 gr BalTip is fairly long. Optimal seating depth would be 2.800"+, but that would put them into the rifling (I assume).

    When you sit them longer you increase the boiler room of the case thus requiring more powder to reach maximum allowed working pressure.
     
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  5. grovey

    grovey

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    If you're going to reload you need a way to repeatably measure your reloads. Both headspace and where your bullet sets in relationship to the lands. Hornady sells comparator sets to do both. The mag box of your rifle may limit your ability to get close to the lands by forcing you to load short enough to feed from the box. If you're single feeding them Your not limited by this. Measurements from your particular rifle will vary from others "even if it's the exact same rifle".
    In a pinch.... you can slice the neck of a sized case with a dremel tool and find the lands by inserting the bullet you're loading in the case and gently closing the bolt on it. When extracting use your finger to keep the ejector compressed and the shell inline as you ease the bolt back .
    Using your finger this way keeps your new found measurement from being drug along your chamber and receiver thus possibly seating the bullet deeper. Once you know what you're dealing with you'll know if you constricted by your mag box, or if you can seat long and start @ 0.020? off. You can repeat the test, but you'll need to size the case again to get it to hold the bullet. Here's one I made to answer this question in the past. It's fairly accurate once you understand how to do it.

    223 OAL 002.JPG
     
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  6. Coyote243

    Coyote243

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    Thank you it’s weird that it varies so much between books and data I’ll definitely post my results
     
  7. K22

    K22

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    While this isn't my preferred bullet for the 243 Win (i.e. 85 Sierra BTHP), I have used the 90 Nosler BT before in the 243 Win with excellent results but I used IMR 4350. Rifle was a Rem 700 which has a lot of free bore so I was never in jeopardy of hitting the lands at a COL of 2.700. There was a lot of jump but the the load shot well (under an inch) in a very wore 243 barrel.

    I like at least one bullet diameter (excluding the boat tail portion) of the bullet seated in the neck. I also prefer to be at least .010" from the lands to prevent a bullet becoming stuck in the lands when I extract a live round and to prevent a high pressure situation.

    I've never seen the need to seat the bullet into the lands to achieve my accuracy goals. Actually many of my rifles shoot better with a jump - I can't say for sure because I'm not an "expert" but I believe this might be due to not so much because of the jump but because the greater seating depth providing more uniform powder burning and reduction in run out. If you examine some of the premium factory ammo you'll discover that in most the bullet is seated well below the SAMMI max COL. I've seen some amazing groups shot at the range with factory rifles and factory premium ammo.

    One of the first things I do with a new rifle is measure the maximum COL for the bullet I intend to use. I measure 3 bullets and use the average of the three. I use a version of the Frankfort Arsenal Tool (mine is home made). It's easy to use, accurate and cheap. I start load develop at .020" off the lands or more if needed to fit the magazine or to obtain at least one bullet diameter seating depth.
     
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  8. Coyote243

    Coyote243

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    Thanks you makes since ... I didn’t think of it as more uniform burn for the jump and fortunately I have a hand trimmer so i get to do it all by hand !! Id love a franklin one day but for now good ol hand trimmer
     

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  9. Coyote243

    Coyote243

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    Looks like I found a sweet spot
     

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  10. Zero333

    Zero333

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    The velocities are all over the place. Did you chamfer & deburr the case mouths properly ???

    What scale did you use for weighing the powder ??

    Was all the brass from the same manufacturer and lot # ??
     
  11. Coyote243

    Coyote243

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    It was shot 9 and 24 are the same powder charge I worked from 36-38.8 and back down 38.8-36 and every case was debarred and as for the scale it’s a Digital lymen but I also check it with the RCBS beam scale
     
  12. Zero333

    Zero333

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    From your notes...

    36.0 = 2,810
    36.2 = 2,692
    36.4 = 2,589
    36.6 = 2,574
    36.8 = 2,753
    37.0 = 2,664
    37.2 = 2,718
    37.4 = 2,831
    37.6 = 2,693
    37.8 = 2,757
    38.0 = 2,769
    38.2 = 2,819
    38.4 = 2,996
    38.6 = 2,843
    38.8 = 2,887

    ===========================

    That's quite the up and down shift in velocities from just 0.2 gr increments.

    I'm thinking...

    Most likely the problem with the velocity discrepancy is the charge weights are way to low for H-4350 with 90 gr bullet in the 243win.

    Hodgdon's H-4350 data STARTS at 42 gr and goes up to 44.5
    Speer data with 90 gr starts at 40 and goes to 44 gr
    Nosler data for 85/90 gr starts at 36 and goes up to 40


    If all else is good...

    Either the powder scale is off
    or the brass is not of the same brand
    or some of the brass has been reloaded more times the others.

    OR the Chronograph is too close to the muzzle... that's if it's a chrono that uses the light screens. It should be at least 10 feet away from the muzzle.
     
  13. Coyote243

    Coyote243

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    Yeah why I was worried about seating depth because there are a lot of differences and all is once fired brass and each projectile was weighed maybe the chronograph might’ve been a little close but I don’t have many options to work with ..
     

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  14. Zero333

    Zero333

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    What rifle are you shooting these out of ??

    Do you know the twist rate ???

    The 90 gr Ballistic Tip is a long bullet and I can't see it being very accurate in a 10" twist.
    A 9.25" twist or faster would be more optimal for this bullet.
     
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  15. Coyote243

    Coyote243

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    Tikka T3X and I’m not sure believe 1/12 but I also have a 223 that 1/7 and it handled 40 grains way nice !
     
  16. Zero333

    Zero333

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    I think Tikka makes the 243win with a 10" twist which is a hair too slow for optimal stability with the 90 gr BalTip.

    I recommend the Siearra 85 gr BTHP Gameking ( # 1530 ). It's a phenomenal bullet for hunting deer and it's VERY accurate.

    If you're gonna tinker more with the 90 gr BalTip, I suggest you work up new loads from 40 gr to 42 gr of H-4350
     
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  17. DJSBRS

    DJSBRS Site $$ Sponsor

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    My Winchester 10 twist would not shoot accurately withe the Nosler 90 BT. Moved to a Remington in a 9.25 and it grouped up nicely.

    DJ

    DJ's Brass Service
    205-461-4680
     
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