AR 15 load starting point?

Discussion in 'Reloading Forum (All Calibers)' started by TrxR, Aug 12, 2018 at 2:40 PM.

  1. TrxR

    TrxR

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    I am building a AR 15 with a 19" barreled chambered in .223 Wylde.

    Im looking for a load starting point.

    Going to try using the following.

    Bullets: Sierra 77smk (9377)
    Brass: IVI military brass
    Powder: 8208XBR
    Primers: CCI BR4

    Anyone have a good charge weight starting point?
    I have seen mentioned that you have to start lower with military brass?

    Thanks
     
  2. Dusty Stevens

    Dusty Stevens COVFEFE Gold $$ Contributor

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    You may want to check sierras load data. Youre going to have a severely reduced case capacity at mag length and not enough barrel length for load data from most that would shoot that bullet. Sierra will happily answer an email from you- theyre great at the customer service
     
  3. Uncle Ed

    Uncle Ed

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    Nothing against this forum but chances are you will get "more" answers in AR15 type reloading forums. Most of the people here do not have 30 round mags on their bolt action benchrest rifles. ;)

    At the m4carbine.net reloading forum they had a very good postings on Sierra 77smk loads and duplicating Black Hills ammo MK262 mod 1 load data.

    https://www.m4carbine.net/forumdisplay.php?72-Reloading-amp-Ammunition

    https://www.ar15.com/forums/armory/Reloading/42/

    I compromised to be in this forum and have a Ruger Ranch .223 that uses magpul pmags for Zombie attacks. :eek:

    [​IMG]
     
    Last edited: Aug 12, 2018 at 3:17 PM
  4. TrxR

    TrxR

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    Thanks I cant join AR15 as they wont allow Gmail addresses. I will try m4 carbine.

    I will also email Sierra as this is a popular bullet for AR precision shooting.
     
  5. XTR

    XTR

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    Service rifle shooters load 77s to mag length all the time. Most shoot 77s from the short lines in rapids where you have to shoot from a mag and 80s from 600 where you slow fire single load. The 77s are very jump tolerant.

    Your load should be somewhere in the neighborhood of 23gr to 23.5gr Work up to it.
     
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  6. Uncle Ed

    Uncle Ed

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    At the Accurate Shooter link below you will find Sierra load data from their manual for the .223 and 5.56 plus much more info.

    223 Rem + 223 AI Cartridge Guide
    http://www.accurateshooter.com/cartridge-guides/223rem/
     
  7. jepp2

    jepp2 Silver $$ Contributor

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    I think you will find this extremely helpful.
     

    Attached Files:

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  8. jepp2

    jepp2 Silver $$ Contributor

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    I have seen IMI, but not IVI. If IMI case capacity is just like the rest.
     
  9. TrxR

    TrxR

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    Nope IVI its the Brass the Canadian Military uses.
     
  10. nicholst55

    nicholst55 Brass Whore

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    Sierra has .223 data for the AR available online. Run a web search for 'Sierra 223 AR data.'
     
  11. Lone Hunter

    Lone Hunter

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    Look above at jepp2's post and he posted the link to the data.
     
  12. Don

    Don Gold $$ Contributor

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    Rem. Brass CCI Primers. R-15 start at 23gr. 69gr. Sierra or 75 gr. Hornady
     
  13. Steve Ladino

    Steve Ladino

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    Got my buddies AR-15 5.56 20" 1/8 twist to shoot 77 grain TMK's @.625/100 yds. with 23.8 grains of Varget and CCI 450 primers at 2.255 COAL Federal brass (looked like NATO Brass) full length resized.
     
  14. Uncle Ed

    Uncle Ed

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    On the main page of Accurate Shooter "here" there is Sierra load data for the .223 and 5.56. Plus tons of accuracy articles on reloading. And this is some of the best info anywhere on the web. ;)

    223 Rem + 223 AI Cartridge Guide
    http://www.accurateshooter.com/cartridge-guides/223rem/
     
  15. Uncle Ed

    Uncle Ed

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    One of the solutions to the early M16 jamming problem was to use harder brass in the 5.56 cases. I assume Canada and the other NATO countries followed in making their 5.56 cases since Canada uses the same basic rifles.

    Below the 1968 Congressional hearings on the M16 jamming problem, they found the 5.56 cases were too soft. And now Lake City cases have the hardest brass and harder than Lapua.

    [​IMG]

    Below the mil-spec requirements for 5.56 cases and the hardness requirements in the lower left.

    [​IMG]
     
  16. TrxR

    TrxR

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    I see sierra list n 140 as their accuracy load and they don't list 8208 at all. Anyone have any experience with n140?
     
  17. natdscott

    natdscott Silver $$ Contributor

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    Yeah, but no.

    I would hazard that 75% or BETTER of all Highpower records ever set with the AR-15 were set with the 77 Sierra, possibly in combination with another bullet.

    It's that good, and was DESIGNED for mag-length AR-15 loads.

    23.8 RE-15
    2.235-2.255" COAL
    Rem 7.5 or CCI BR4
    Lake City Brass
    0.002-3" tension for mag loads, 0.001" tension for slow fire loads
    No Crimp
     
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  18. damoncali

    damoncali Gold $$ Contributor

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    24 grains of Varget under a 77 SMK at mag length seems to be a pretty common load in high power circles. It’s a little stout, so work up to it.
     
  19. 55fairlane

    55fairlane

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    I shoot a RRA NM (service) rifle 20 inch 1 in 8 twist wylde chamber

    My across the course load is

    77 SMK
    23.2 grain IMR 8208XBR (max load )
    2.250 C.O.A.L
    CCI small rifle primer

    This load will just plain hammer at 600 yards

    This load data is for reference only

    For 200/300 yard matches

    68 grain Hornaday (not match)
    23.5 grains IMR 8208XBR
    2.235 C.O.A.L

    68 grain Hornaday match
    23 grains IMR 8208XBR
    2.250 C.O.A.L

    69 grain SMK
    23.5 grains IMR 8208XBR
    2.235 C.O.A.L

    These loads will hammer

    This data is for reference only
     
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  20. Dusty Stevens

    Dusty Stevens COVFEFE Gold $$ Contributor

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    I shoot n135 under a 75bthp hornady in mine with a cle chamber and its the best bullet in mine by far
     

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