Speer 24446 (55gr .223 Gold Dot) Testing

[WS6]

With all of the 55gr Gold Dot so readily available, I decided to perform a comprehensive test on it to determine its viability. I chronographed 60 rounds of it. All groups shot were chronographed, although targets and data were not linked. That data directly follows:

16.1" DDM4, CHF barrel, Chrome lined, approximately 5,000 rounds through it. Unless otherwise noted, Surefire 556-212 suppressor is present for all testing.
Chronograph at 10' from muzzle unless otherwise noted.

Shot string #1
2960
3019
2981
3004
3012
2004
2991
3002
3019
3022
AVG: 3001.4

Shot String #2 (unsuppressed)
3005
3011
3015
2979
2998
2965
2986
2987
2966
3011
AVG: 2992.3

Shot String #3
3005
3020
3034
2992
3010
3011
2982
3021
3041
3051
AVG: 3016.7

Shot String #4
3002
3003
3011
3005
3008
3027
3033
3001
3014
3032
AVG: 3013.6


100 yard chronograph placement, Shot String #5:
2534
2523
2551
2541
2529
2545
2513
2559
2537
2538
AVG: 2536

100 yard chronograph placement, Shot String #5:
2521
2552
2562
2524
2524
2559
2553
2545
2565
2547
AVG: 2545.2

The groups fired measure:

1.73" CTC
1.935" CTC
1.635" CTC
1.785" CTC
2.145" CTC
2.345' CTC (*last group fired, fired hastily after jogging back from the 100 yard line. This group was video'ed and you can see the split times between shots are not conducive to precision. It was also fired on a target which I had not taken a sharpie to, to help stand out better under 4x magnification, and is more indicative of shortcomings of the shooter vs. the weapon system.)

Average Group Size, accounting for ZERO fliers or shooter errors: 1.929"

Rifle used is as described above, optic used was a nightforce 1-4 FC-2 reticle. Rifle was rested on a hard sand-bag under the fore-end, with the buttstock freefloated/resting against the shoulder. Groups fired from seated at a bench.

100 yard Chronograph videos:
http://www.youtube.com/watch?v=pjZSbn7iHV4
http://www.youtube.com/watch?v=sJRK72d3YVs


Ballistic Coefficient is stated as .222, but regressing my 100 yard velocities shows a BC of 0.190. However, if tested over 2-400 yards distance, this may well change, as I have seen before people regressing 100 yard velocities to find BC, later taking the test to 200+ and the BC "rising", so take this with a grain of salt. That said, at 100 yards, that's what she's clocking.

Also tested was expansion and penetration in water-filled milk-jugs spaced 2" apart from each other. A total of 2 jugs were penedtrated through/through, with the first jug being blown wide floppy open. The second jug had a nasty ragged hole through/through, and the 3rd jug had a ragged entry hole, and no sign of trauma to the far wall. The impact distance was 50 yards from the muzzle, and calculated to be at 2705fps +-50, although the chronograph was not in play for that shot. The expanded slug measures 0.590" across it's widest petal span, and 0.354" between the petals at its narrowest, for an average expanded diameter of 0.472". 2 unfired projectiles were found to weigh 55.1gr, and this expanded projectile was found to weigh 41.8gr. for a total projected loss of 13.3gr and a retained weight of 75.8%. It is pictured below:

[Straight Shooter]

Great info Ive been wondering about.
Ive got a small stash of this...was planning on sighting in and loading a few mags up for HD/SHTF or whatnot.
QUESTION: Id like to use a 50/200 yrd zero..thoughts? Or other suggestions welcome.
If I go with the 50/200..where will I be at 300?

[WS6]

I prefer a 100 yard zero. It's much more precise and you're never holding under. I'll run the dope when I'm home. What distances do you want?

[Straight Shooter]

I prefer a 100 yard zero. It's much more precise and you're never holding under. I'll run the dope when I'm home. What distances do you want?

THANK YOU. Ive got a 100 yd zero now with M193...Ill keep it then with the Gold Dot. Can you run it out to 400?
I enjoy your posts & appreciate your time, sir!

[WS6]

THANK YOU. Ive got a 100 yd zero now with M193...Ill keep it then with the Gold Dot. Can you run it out to 400?
I enjoy your posts & appreciate your time, sir!

Thanks!

With a height over bore of 2.5, and a 16" barrel, and a BC of .190, here is the data with a 100y zero (50y zero data is to the right):

25y:-1.5 vs -1.1
50y:-0.7 vs 0.0
75y:-0.2 vs 0.8
100y:0.0 vs 1.4
150y:-0.7 vs 1.4
200y:-3.0 vs -0.3
250y:-7.3 vs -3.9
300y:--14.1 vs -10.0
350y:-23.8 vs -19.1
400y:-37.3 vs -31.9

The other aspect is that a precise zero at 100 is a lot less error prone than at 50, with a 1moa or worse platform. Is that 50 yard zero 0.3 high or low? Matters a lot less with the 100 yard zero if it is high or low by the same if you dial out to 400.

[Straight Shooter]

Thanks!

With a height over bore of 2.5, and a 16" barrel, and a BC of .190, here is the data with a 100y zero (50y zero data is to the right):

25y:-1.5 vs -1.1
50y:-0.7 vs 0.0
75y:-0.2 vs 0.8
100y:0.0 vs 1.4
150y:-0.7 vs 1.4
200y:-3.0 vs -0.3
250y:-7.3 vs -3.9
300y:--14.1 vs -10.0
350y:-23.8 vs -19.1
400y:-37.3 vs -31.9

The other aspect is that a precise zero at 100 is a lot less error prone than at 50, with a 1moa or worse platform. Is that 50 yard zero 0.3 high or low? Matters a lot less with the 100 yard zero if it is high or low by the same if you dial out to 400.

I really appreciate that..thank you again sir.

[vicious_cb]

Thanks for the data. Im really wanting to like the 55gr GDSP but the barrier penetration is just lacking. Speer has their gel data for the 75gr GDSP up on their website now and looking at the gel testing Im willing to spend a little extra for the increased barrier capability of the heavier bullet.

223 Rem 55gr GDSP 24446
Bare Gelatin
Velocity 3013
Penetration 14.00
Expansion 0.488
Retained Weight 43.6
% Wt. Retained 79.27

223 Rem 75gr GDSP 24475
Bare Gelatin
Velocity 2502
Penetration 17.05
Expansion 0.483
Retained Weight 58.6
% Wt. Retained 78

223 Rem 55gr GDSP 24446
Safety Glass
Velocity 3013
Penetration 7.50
Expansion 0.344
Retained Weight 15.2
% Wt. Retained 27.64

223 Rem 75gr GDSP 24475
Safety Glass
Velocity 2539
Penetration 13.35
Expansion 0.368
Retained Weight 43.4
% Wt. Retained 58

http://www.le.vistaoutdoor.com/ammun...e/default.aspx

[WS6]

Thanks for the data. Im really wanting to like the 55gr GDSP but the barrier penetration is just lacking. Speer has their gel data for the 75gr GDSP up on their website now and looking at the gel testing Im willing to spend a little extra for the increased barrier capability of the heavier bullet.

223 Rem 55gr GDSP 24446
Bare Gelatin
Velocity 3013
Penetration 14.00
Expansion 0.488
Retained Weight 43.6
% Wt. Retained 79.27

223 Rem 75gr GDSP 24475
Bare Gelatin
Velocity 2502
Penetration 17.05
Expansion 0.483
Retained Weight 58.6
% Wt. Retained 78

223 Rem 55gr GDSP 24446
Safety Glass
Velocity 3013
Penetration 7.50
Expansion 0.344
Retained Weight 15.2
% Wt. Retained 27.64

223 Rem 75gr GDSP 24475
Safety Glass
Velocity 2539
Penetration 13.35
Expansion 0.368
Retained Weight 43.4
% Wt. Retained 58

http://www.le.vistaoutdoor.com/ammun...e/default.aspx

Gary Roberts posted data showing 55gr gdsp does 11.8" through auto glass at a 2760ishfps impact velocity. Search on this site for 5.56 golddot.

I'm skewing things for greater secondary projectile incidence and 500fps more velocity with adequate penetration and identical expansion.

[jdgiii]

Thank you for sharing your results. I'd like to see this same test with the 62 gr gdsp. If you are willing and able pm me your address I will send you 60 rds.


Sent from my iPhone using Tapatalk

[WS6]

Thank you for sharing your results. I'd like to see this same test with the 62 gr gdsp. If you are willing and able pm me your address I will send you 60 rds.


Sent from my iPhone using Tapatalk

I've already done accuracy and water jug testing. It was identical except a bit more penetration. All I lack is chrono data on it, and 20 rounds would accomplish that.