My Armalite Ultra SASS (300SAUM)

Discussion in 'AR15/10 Rifles' started by c_bass16, May 4, 2012.

  1. c_bass16

    c_bass16 Well-Known Member

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    Sep 22, 2009
    [​IMG]

    I worked up this load with just 12 shots at 100yds last winter and with a 3 shot chrono average, sent my last 3 rounds to 1105yds to get a drop test.
    Here is the innitial group.
    [​IMG]

    Here are the first rounds sent beyond 100yds. Not bad for the first time at that range.
    [​IMG]

    Later in the season, after loading up.some more rounds and tweaking the seating depth, I took it back to 1150 with a bit of improvement.
    [​IMG]

    I saw some minor pressure signs but occasionally, they were worse, so for safety sake, I decided to look for a little slower load to avoid complications shooting in the summer.

    In the final stages of (new) load development, got a charge and fine tuneing the depth and I think I'm about ready to call it "good enough"

    Took it out to 500 today and was pleased, but my chrono gave goofy data so I'm going to plug some numbers and head out for a 5 shot test tomorrow.
    Maybe 800 this time.

    View through the 8-32x56 NXS
    [​IMG]

    3 shots at 500
    About an 8mph wind was in my face switching from 12 to 2.

    Armalite 300 SAUM
    210 VLD, FGMM 215 primers
    Rem brass at 2.005", RL17 powder, 2.187 to ogive

    [​IMG]
     
  2. The7mmSTW

    The7mmSTW Well-Known Member

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    Feb 2, 2012
    Beautiful:D
     

  3. c_bass16

    c_bass16 Well-Known Member

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    Sep 22, 2009
    Went out today to verify my velocity at 800, and hope to keep a sub moa group.

    Ended up being 815yds but my set up was less than reliable.
    Shot off my bipod and monopod because the angle was too wacked out to use my rear bag correctly. -4 degree angle and rough, hard ground.
    Wind was again in my face 8-10mph from 12-1 o'clock but this time I didn't make any adjustments...just held right edge of the yellow square.
    Mirage got crazy pretty quick, but gotta learn to deal with it till my cover gets here.

    Here is the home made "Shoot-N-See" target through the scope on 32x at 815yds.
    22"x28" with a 3"x3" Post-It to aim at.

    [​IMG]


    As for the drop test, I'm happy...velocity needed for 500 held true at 815 so that's good, but I'm hoping to improve my form/technique before next fall. At any rate...she'll kill a deer.
    Sent the first 3 at an old target at 100 to make sure I reset my turrets yesterday...I have a problem with that.
    Here were my last 7 at 815yds.
    Pretty sure the one hit on yellow was my first shot because I couldn't see it and was worried.
    2, 3 and 4 were on the left...5, 6 and 7 were on the right. Very easy to pick out the pink on black.

    Elevation adjustment was exactly 20 minutes.
    Conditions....
    29.87 Hg
    66% humidity
    86°
    Altitude: 340ft
    Angle -4
    8-10mph from 12-1:00

    [​IMG]
     
  4. Kino74

    Kino74 Member

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    May 24, 2009
    Very nice. I think Armalite may have made a mistake discontinuing the .300 saum.
     
  5. c_bass16

    c_bass16 Well-Known Member

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    I agree 100%.
    At the time, sales were falling so bad for everyone...that I understand the reason....but the new companies that are coming out with their own, is proof that it is still a wanted (even if not needed) option.

    I got this upper used with intentions of rebarreling to a 7mmSAUM but it shot to good to mess with.
    Might build a second upper and just use the same bcg since a bolt is impossible to find.
    Everyone says over gassing is the problem, but with an adjustable gas block...its all good.

    Could use this as the hammer and build a barrel burner in 6.5saum since I'm already building a 7mm SAUM on a pre64 M70.
     
  6. Kino74

    Kino74 Member

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    It would be nice if they brought back some simple uppers in .300 saum. It could be cheap to do I would think. :)
     
  7. c_bass16

    c_bass16 Well-Known Member

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    Went back out today with great success.

    Decided to split the distance and try 700 yds.

    Literally no wind...used my windicator powder both at the target and the shooting location and powder fell strait down. Best conditions possible.

    29.97
    Elevation 345'
    48% humidity
    -4 shooting angle
    81 degrees
    zero wind

    With my first range reading from ffp to target, I got 668 three different times, so I trusted it, plugged data, dialed (15.1 minutes) and sent 5 rounds, recording velocity on each shot.
    1.) 2677
    2.) 2695
    3.) 2706
    4.) 2712
    5.) 2720

    [​IMG]


    Took drive down for a better look and ranged back toward a box blind that was behind my shooting location about 16 steps. Range said 719-720 on five different tries...so when I got back to my shooting location, I plugged in 703 instead since I was getting a stronger reading off a reflective object.

    Adjusted to 16.3 minutes and 1/2 left for spin drift and sent 3 more rounds. Couldn't see the 2nd impact so I assumed it hit in the yellow...but when I got to the target, noticed it was almost directly in the same hole as the previous. Three shots with recorded velocities.
    1.) 2753
    2.) 2759
    3.) 2771

    [​IMG]


    I think I need to figure out how to keep my velocity more consistent. Not saying it is responsible for the vertical string, but it sire looks like it.

    Any thoughts or suggestions? It's still less than 5" of vertical at 700yds...but it would be nice to shrink that up.
     
  8. Outlaw6.0

    Outlaw6.0 Well-Known Member

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    Feb 18, 2010
    That is a great looking rig & equally good shooting. Bolt guns beware.... the gassers are coming...:D

    As far as consistency... autos are difficult. I will assume they are all trimmed to the same length... Have you annealed your cases? Have you measured neck thickness? Tried different primers?

    Good places to start... i'm running RL-17 in a Lazz Patriot.... wow... great velocity & amazing accuracy... I too am playing with getting my consistency down.