Gentlemen, I present... the ".220 REDLINE"

Discussion in 'Varminter & Hunting Forum' started by fredo, Sep 15, 2017.

  1. fredo

    fredo Silver $$ Contributor

    Joined:
    Feb 6, 2015
    Messages:
    902
    Looks like Christmas is coming early this year!!!
    'Smith just sent me this...
    [​IMG]

    [​IMG]

    Merry Christmas, everyone!!!

    Parker, get 'yer chinstrap buckled up...we're almost there ;)
     
    Last edited: Dec 23, 2017
    Grant G, long40shot, JSH and 5 others like this.
  2. snert

    snert Gold $$ Contributor

    Joined:
    Jan 12, 2009
    Messages:
    3,215
    Googles on, leather helmet secure, and a piece of rawhide for between my teeth, I am ready to pull the trigger!
     
  3. Shoebox

    Shoebox

    Joined:
    Nov 3, 2016
    Messages:
    173
    Wormhole.jpg Googles, leather helmet, that should help "when the sky is falling"
    Wishing all a merry Xmas & fantastic new year !!!
    Looking forward to results

    Shoebox
     
  4. 17VLD

    17VLD

    Joined:
    Mar 15, 2006
    Messages:
    316
    Looking forward to seeing chrono reports and targets.
    Maybe even some demolished coyoteso_O
    Matt
     
  5. MTSLW

    MTSLW Silver $$ Contributor

    Joined:
    Aug 13, 2012
    Messages:
    69
    I'm really looking forward to seeing how this works out. The 85 Gr RDF that just came out might be interesting as is the 95gr Sierra. Just need a good guinea pig. We might have to start sending you bullets!
     
    fredo likes this.
  6. Yote Hunter

    Yote Hunter

    Joined:
    Feb 28, 2015
    Messages:
    174
    Anyone know what the bullet OAL measurement is for the 85 gr Nosler RDF .22 Caliber bullet is?
     
  7. 284winner

    284winner Silver $$ Contributor

    Joined:
    Dec 6, 2015
    Messages:
    1,916
    1.135 in length. 0.498 BC. These are from Nosler. Nosler gives it an 8 twist recommendation.
     
    FRNOWSTL likes this.
  8. Phil

    Phil Gold $$ Contributor

    Joined:
    Feb 16, 2006
    Messages:
    3,380
    Dang Fred, seems like yesterday you were looking for a tube and here we are all chambered up and ready to holler......;)
     
  9. 357Mag

    357Mag

    Joined:
    Dec 25, 2006
    Messages:
    1,024
    Fredo -

    Howdy !

    I took a second look @ Homer Powley's "Expansion Ratio" table ( Guns & ammo 1974 Annual "Powley Papers" ). As an accurization of what I previously stated about expansion ratio....

    - In a notional 28" lg .224" caliber barrel, a sample charge of 70gr powder would seem to suggest an
    expansion ratio of 4.5 .
    - This is a tad better than the 4.0 ER figure I previously quoted, for an earlier estimated 72gr charge
    shot in the same length 28" .224" cal barrel.

    The sample chart Homer provided, did not go lower than 4.0 on expansion ratio.


    With regards,
    357Mag
     
  10. fredo

    fredo Silver $$ Contributor

    Joined:
    Feb 6, 2015
    Messages:
    902
    Thank you for the info, 357 Mag!
    I'm not terribly familiar with how your expansion ratio value estimates translate into projected performance. Would you be so kind as to explain?

    Also, reckon the capacity of a finished .220REDLINE would be nearer to ~70grains, given the subsequent (minimal) loss of volume from the necking down process...

    Sitting on "GO" here to get this in hand! Just waiting on a Cerakote batch job to wrap up to take the shine off that Brux. Working with some test loads will make for a nice breakup of the winter doldrums when I can't get away to chase coyotes. Once I get a mild firing on some brass, can measure capacity & get to to tweakin' QL parameters to help narrow down a load.

    Won't be long now!
     
    17VLD, snert, MTSLW and 1 other person like this.
  11. snert

    snert Gold $$ Contributor

    Joined:
    Jan 12, 2009
    Messages:
    3,215
    You know you have to have this thing Field ready by May Fredo, so I can wring it out at the Space Place or even better "across the Valley"...

    I am keeping my NY residency just for that reason!

    Snert
     
  12. 17VLD

    17VLD

    Joined:
    Mar 15, 2006
    Messages:
    316
    I remember as a kid hearing about a place called Space Farms.They used to raise minks,I heard that they fed them ground up woodchucks,wonder were all the chucks came from:D
    Matt
     
  13. Danny1788

    Danny1788

    Joined:
    Feb 24, 2011
    Messages:
    336
    Chambers strait on the 4 jaw that's a big No No. how can the barrel pivot to dial in the bore. But besides that its a cool project.
     
    gtl1946 likes this.
  14. fredo

    fredo Silver $$ Contributor

    Joined:
    Feb 6, 2015
    Messages:
    902
    P, you and lil' P are on trigger detail...I'll roll tape:)
    Speaking of which, have last years chuck whackin' footage on a DVD for ya. Hope to get up in the next few weeks and hand it over. Besides, we gotta go coyote calling together already!!!
     
  15. 357Mag

    357Mag

    Joined:
    Dec 25, 2006
    Messages:
    1,024
    fredo ,

    Howdy, again !

    Tehre's info abut " expansion ratio " and bore capacity written by individuals that are both more knowledgeable and more articulate than myself.

    Until we can talk more on these topics, here's one sample read:
    https://www.thefreelibrary.com/Bore+capacity+&+expansion+ratio.-a03578530

    I DK whether you have P.O. Ackley's 2 volumne tretise " Handbook for shooters and reloaders " ?
    If you do , please take a look @ pg 16 5 or so.... wherein he talks about " bore capacity ".

    We'll talk, again, soon as I get the chance.


    With regards,
    357Mag
     
  16. 357Mag

    357Mag

    Joined:
    Dec 25, 2006
    Messages:
    1,024
    fredo -

    Howdy !


    More on " Expansion Ratio ".....

    The following is a quote from the " Guns & Ammo 1974 Annual " ( "Powley Papers " ):

    ..." Mr. Powley was also able to find a way to figure velocity for a given peak pressure.
    It can be calculated from the following ( using the Powley Computer ):
    1. Powder weight divided by bullet wt
    2. Density of loading ( case capacity divided by powder wt )
    3. Expansion Ratio ( ER )

    " We already know figures Nos. 1 & 2, so the Computer next finds Expansion Ratio from the Case Capacity, Barrel Length and Calibre. Finally, extensive tables on the Computer give muzzle velocities for a very wide range of Expansion Ratios and Ratios of Charge to Bullet weights. "

    Comment:
    A wildcatter can use ER to compare various wildcat designs, trading off things like barrel length and case capacity for a given caliber; and seeing how projected muzzle velocity if effected.
    Using either computed ER values or those found on a reliable table of expansion ratios, the case designer can see whether certain chosen project goals might be obtainable.
    For example: Say the wildcatter wants to make a .224" cal wildcat w/ higher velocity potential than the .220 Swift fetures, when shooting 55gr bullets ( as a reference ).

    Homer Powley listed the expansion ratio for a 24" barrel .220 Swift as 5.6 . The wildcatter then runs computation on the Powley computer ( example ) for a .224" cal case w/ 70gr H2O case capacity.
    He finds that even w/ a longer 28" barrel, his wildcats' forecasted ER will be 4.5 The wildcatter likes the calculated vel seen on the computer for his design, and decides to accept the probable lower barrel life the 4.5 ER portends. Another wildcatter might reach a different conclusion, based on his own particular interests, thoughts; opinions.

    Let's talk, again!


    With regards,
    357Mag
     
  17. 357Mag

    357Mag

    Joined:
    Dec 25, 2006
    Messages:
    1,024
    fredo -

    Howdy once again !

    Say... I hope the response I sent immediately prior to this one did not sound smart-aleky.
    My intent was to simply use numbers/values that we were already talking about as the sample exercise,
    in-lieu of using other numbers for a different wildcat.

    Another use for expansion ratio: Say you run some numbesr through the [ Powley ] computer, and you are not seeing the projected velocity you were "shooting for". I don't have one in front of me, and don't recall how high the velocity tables on a Powley Computer go ?

    My point:
    IF you weren't reaching a point near the velocity goal, you'd adjust expansion ratio ( ER ) via either choice of a larger capacity wildcat and/or increase barrel length. You'd have a good sense of what ER zone needs to be reached, to meet your need. ER can be used then, to help skewer the necessary case capacity;
    which can then be used as useful input on potential candidates for the parent brass


    With regards,
    357Mag
     
  18. snert

    snert Gold $$ Contributor

    Joined:
    Jan 12, 2009
    Messages:
    3,215
    I will be thre for a week starting Next friday...tell me ahead of time cause all my stuff has moved to PA
     
  19. fredo

    fredo Silver $$ Contributor

    Joined:
    Feb 6, 2015
    Messages:
    902
    [​IMG]
    Brux #4 finished at a smudge over 27". Cerakote Elite in Midnight color looks good!

    After just getting back from whackin' some coyotes with my ol .22-243AI, even more excited to what a couple-3 hundred more FPS (I hope) on top of that awesomeness might be like!!!
     
  20. nmkid

    nmkid Gold $$ Contributor

    Joined:
    Dec 31, 2014
    Messages:
    1,451
    OK. This is starting to get interesting. Got to thinking...Wonder what this would do with the new Sierra 95 gr. bullet?
     
    Last edited: Jan 29, 2018

Share This Page