I fired several rounds today. Function was good, and recoil impulse was more of a "shove". Hard to explain, but it felt like I was moving more than M193 down the barrel, but not snappy.
I fired 2 rounds into milk jugs full of water, at 15m distance, from a 16.1" DDM4 with a Surefire 556-212 suppressor in place. Both rounds performed identically, penetrating 3 jugs fully, and bouncing off of the far inside wall of the 4th jug trying to get out, but not quite making it.
Bullet #1 measures 0.557" at the widest point, and 0.365" at the narrowest point (a juncture between petals), for an average diameter of .461". It is 0.378" high from the front of the mushroom, to the base of the bullet shank, although petals have folded beyond the base of the shank.
Bullet #2 measures 0.5415" at the widest point, and 0.355" at the narrowest point (a juncture between petals), for an average diameter of 0.448". It is 0.379" high from the front of the mushroom, to the base of the bullet shank, although petals have folded beyond the base of the shank.
I am sending some Gold Dot to be evaluated at low impact velocities in gel, chronographed (The data I now have, shows, 2199fps from a 10.5" barrel, and 2419fps from a 24.5" barrel, and gel/animal data is forthcoming.) and shot into hogs and deer.
The Gold Dot has a sealed and staked primer, and no neck sealant.
I regressed Speer's data on the 75gr Gold Dot, and achieved a functional BC of 0.4.
I verified this by plugging in 0.222 for their 55gr load, and 0.27 for their 62gr load (this is the 64gr load's published BC).---These are published BC's.
I checked all residual velocities at 300 yards with the calculator. Using the above data, All of the loads were within a dozen FPS of the published data, using published MV.
It seems for all the world that Speer is claiming a 0.4 +- 0.01 BC for their 75gr load. I have not found it published, but the velocity data regressed indicates such, directly.
Feel free to check my work.
http://federalpremium.com/downloads/...sue/index.html
*The 75gr Sciroco II is 0.419, and the GD looks at LEAST as streamlined, with a slightly blunter tip...so maybe it's legit?
Here is a revised chart, using 0.4 as the BC.
Today, I fired a round into water jugs (milk-jugs) at a paced 95m. My paces are pretty accurate (about 10m +- over 400m, measured w/surveyor wheel, numerous times, when I lived out in S TX). I used my 16.1" DDM4, suppressed. The round expanded VIOLENTLY, and penetrated the same number of jugs as at 15m. Three, with the round coming to rest in the 4th, after ALMOST breaking out of the outer most side. The bulk of the fragments shown were found in the 2nd and 3rd jugs. This round is still moving "too fast" at 100ish yards to retain 100% of its mass. It is my opinion that the BC really is around 0.4, and this round has some legs on it!
Here it is, shown next to the one fired at 15m, for reference (the fragmented round is, ironically, the one fired at 100-ish yards):
Eta: official BC is 0.373
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Originally Posted by ColtSeavers
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