129 gn SST, OAL, compressed loads

[Bedford]

Hi,

I'm getting back into reloading (after ~15 yrs) and I'm a little nervous about loading for semi autos. I feel fine with bolt guns.

Anyway, I was going to go by A.A. reloading sheet, and thought I would use AA2520, and 123 grain SST's. It turns out that there is is no such thing, and I got 129 grn by mistake.

I searched online and found that someone uses 28 gn AA2520. I tried this, with an OAL of 2.260, and while it loaded easily, I'm pretty sure it compressed the load. Just by eyeballing it looks like the bullet would easily push down into the powder. I tried throwing smaller powder charges, down to 24 grains, and it still looks like the bullet will push down into the powder.

Is the Grendel supposed to have suppressed charges?

thanks!

[rasp65]

Generally all the top loads with 2520 are compressed. The AA data that I have shows 29.4 grains of 2520 with the 129 SST in an AA case with an OAL of 2.260.

[bobke]

if you'll bear with it, read through this thread for some excellent advice on powder settling, drop tubes, vibration enhanced powder accomodations. pretty helpful, in my application.

http://www.65grendel.com/forum/showthread.php?2360-More-counsel-and-wisdom-please

[Bedford]

Thanks, guys, exactly what I was looking for!

[txgunner00]

8208 leaves plenty of room and gives me good results with 129 SSTs. There have been a case or two of AA2520 loaded to the max causing problems in hot conditions.

[sneaky one]

Bobke, Hoots idea works,( so does-- get a 10"-15" drop tube. fill case with the proper powder wt., then gently hold against the outside of your brass tumbler- with a small thin piece of foam in between.

[bobke]

I worked with a version of Hoot's idea, using my old VibraTek tumbler and a loading block with 25 rounds, covered to restrict powder from jumping out. 28.25 gr of 8208 went fm junction of neck and shoulder to junction of low shoulder and case body, freeing up some valuable space for deeper seating requirements of rear weighted bullets. Worked like a champ after a few minutes fiddling with vibration frequency, etc.

[LRRPF52]

Here's the data I got for the 129gr SST at:

2400fps

at sea level

scope height 2.7"

Range    Velocity    Energy     Trajectory         TOF          Drift
      (yards)     (fps)     (ft-lb)       (MILS)         (sec)         (MILS)
         [B] 0 [/B]     2400        1650           0.00         0.0000         0.00
        [B]100[/B]      2255        1456          -0.00         0.1290        -0.19
        [B]200[/B]      2114        1281          -0.58         0.2663        -0.40
        [B]300[/B]      1979        1122          -1.49         0.4130        -0.62
        [B]400[/B]      1850         980          -2.56         0.5697        -0.85
        [B]500[/B]      1726         [COLOR="blue"]853[/COLOR]          -3.77         0.7377        -1.10
        [B]600 [/B]     1609         741          -5.12         0.9177        -1.37
        [B]700[/B]      1499         643          -6.61         1.1110        -1.65
        [B]800[/B]      1397         559          -8.27         1.3184        -1.95
        [B]900 [/B]     1305         487         -10.12         1.5408        -2.26
       [B]1000[/B]      [COLOR="blue"]1223[/COLOR]         428         -12.16         1.7785        -2.59

Scwag173 said that a Hornady tech told him the SST is meant to expand at 1200fps + velocities, which is a very low threshold. Seems like a really nice bullet to use.

ETA: SST expansion is at 1800fps and above, not 1200fps.

[LRRPF52]

Here it is in inches with a 200yd zero out to 500yds:

____ Range    Velocity    Energy     Trajectory         TOF          Drift
    (yards)     (fps)     (ft-lb)     (inches)         (sec)       (inches)
          0      2400        1650          -2.70         0.0000         0.00
         50      2327        1551           0.49         0.0635        -0.17
        100      2255        1456           2.07         0.1290        -0.70
        150      2184        1366           1.95         0.1965        -1.60
        200      2114        1281          -0.00         0.2663        -2.89
        250      2046        1199          -3.89         0.3384        -4.58
        300      1979        1122          -9.86         0.4130        -6.70
        350      1914        1049         -18.04         0.4900        -9.27
        400      1850         980         -28.60         0.5697       -12.30
        450      1787         915         -41.70         0.6522       -15.82
        500      1726         853         -57.51         0.7377       -19.86

That would give you a 10" Point Blank Zero out to 260yds.

[Schwag173]

Scwag173 said that a Hornady tech told him the SST is meant to expand at 1200fps + velocities, which is a very low threshold. Seems like a really nice bullet to use.

The impression he gave me was that the SST was a 'quick-expand' while the Interbond, with it's thicker jacket, was a 'slower-expand' giving better penetration while expanding. I'm thinking SSTs for whitetails and Interbond for black bear.

[Drifter]

Cross-sectional view of SST's jacket looks very similar in thickness to the A-max (at least on the forward half of the bullet), but the Interlock feature of the SST should help it to stay together for better penetration at higher impact velocities. SST appears to be one of the few bullet designs that might do quite well on deer at both short and long distances (in the realm of Grendel speeds). I look forward to trying it.

Cross-sectional view of Interbond's jacket appears to be thicker, so no surprise that it should penetrate more.

[8x9elk]

What loads did you use to get these results?