223 ftr 7 twist surprise

Discussion in 'Small Stuff--22s, 20s, and 17s' started by Hammer47, Apr 15, 2018.

  1. Hammer47

    Hammer47 I suffer fools poorly. Silver $$ Contributor

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    Had the 223 at the range today tuning with 80 gn Bergers with good success. Had about 35 brass that needed to be fireformed to this chamber so I loaded them with 8208 and sierra 52 gn target bullets. I was expecting NOTHING in the way of accuracy out of a 7 twist bbl but was surprised to get sub 1 inch groups with 5 different powder charges. The groups were mostly 3 or 4 in a quarter inch then the "fliers" made the groups 1 inch or smaller. The range was 200 yds...............Imagine, a load used far from it's intended use performing like this? Blew me away.
     
  2. Rsadams

    Rsadams

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    My AR 1/7 twist will shoot the 50gr varment load in the AE black box like a Lazer beam... People don't think they will shoot light weight bullets well but I have seen them do it alot... Never gone below 50gr though....
     
  3. Twitchy

    Twitchy Brass Junky

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    I had outstanding results by chance with Sierra's 55g Blitkings in a 1:7.
     
  4. Boatschool02

    Boatschool02 Silver $$ Contributor

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    Same experience with a 7T 16" Krieger. Shot 55 blitzkings under 1.2" at 200 and 60 grain flat backs under 0.8." That's 5-shot groups from a bipod out of a short gas gun repeated across multiple charge weights and powders. Every now and then I'd have a super small group with the SMK 69s, but at 100 and 200, they were not as consistent as the two above... even though I really wanted my testing to reveal a different outcome.
    FWIW, I also had some excellent groups with the lighter (52/53) SMKs as well.
    I came to the quasi-conclusion that in that gun, my testing wasn't really demonstrating raw accuracy potential as much as jump tolerance while loading to mag length. I have no doubt the 77/80s, single loaded could be nuanced into better performance.
     
  5. Ned Ludd

    Ned Ludd Gold $$ Contributor

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    Going with a [much] faster-than-necessary twist typically isn't much of a problem, especially with a .223 Rem. I've shot 40 gr bullets out of a 7-twist .223 with no issues whatsoever. It's going the other direction and underspinning bullets where the trouble starts.
     
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  6. 1lnbrdg

    1lnbrdg Silver $$ Contributor

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    We were doing load testing on a calm day at 600 yds with 77 and 80gr bullets.

    1 of the guys shot a string with 69gr bullets, about 4" group, then he shot 55gr HPBT's.

    I was in the pits. The 55's shot an 8" group but they all came in subsonic. It's just a bit different hearing the "Tic" when the bullet goes thru the paper and then the sound of the report just behind it.
     
  7. Beau

    Beau

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    I only develop loads for 77 or 80 gr bullets. Every lighter bullet gets the same powder charge as the heavies. They all shoot great.
     
    Last edited: Apr 26, 2018
  8. Rstrick0352

    Rstrick0352

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    I know this is the wrong caliber but I shoot 125gr Nosler BTs our of my 10twist 16” bbl .308win into little bugholes at over 3k fps. Fantastic south GA deer load.
     
  9. XTR

    XTR

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    The dysfunctional relationship with light bullets usually starts when you try to drive a 40gr bullet from a 1:7 at 3800 or 4000 or what ever the max you can drive those little buggers. They have a tendency to turn into smoke at about 75 yards.
     
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