April 11, 2018 at 11:56 am #50062
Hey there powder gurus. Got a question for ya.
I’m trying to push a 180 grain SGK at 1800FPS from my 7.5″ 300BLK barrel.
I had H4198 on the shelf, so I loaded up 17.4 grains and it got me 1468FPS.
Looking at the data, it looks like AA1680 gives the best speed per grain, but I thought I’d ask you guys.
This is the objective: I’m looking to use this MBT AR pistol in 300BLK to deposit as much energy as possible, in as small a rifle as possible, to targets that are 75 yards away or less. I have ZERO interest in shooting subsonic with this weapon. It weighs only 6.5lb loaded with a 20 round magazine, and I want those 20 rounds to be pumping out of there as hard as possible. IE: DRIVE IT TILL THE LUGS SHEAR OFF AND BACK OFF A GRAIN. Im not interested in epic precision either. This is a close range firearm, so 6″ at 100 yards is totally acceptable.
What say you?
April 11, 2018 at 2:31 pm #50065
170gr RD style PB @ ~ 1650. 18″ carbine (50 yds), short pistol will be ~10% slower. 17gr CFE blk or 1680. Rested on a bag and me on the back. More space in there but haven’t tried for faster yet. Primer pockets are still good. H110 seems to run out of steam ~ 170gr.
April 11, 2018 at 5:00 pm #50067
Thanks Popper. Thats exactly what I was thinking of trying. CFE BLACK seems like a good choice.
<p style=”text-align: left;”>The 7.5″ barrel strips 180FPS off the book figures that are based on a 16″ barrel. I figure that would be 200 FPS less than your 18″ barrel produces.</p>
April 11, 2018 at 6:37 pm #50068GlennParticipant
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Hodgdon shows CFE BLK giving the highest velocities from rifle barrels.
I’m sure you’ve clicked on everything in Quickload, but it looks like you’ll be stuck around 1600-1650-ish without going over 60kpsi.
April 11, 2018 at 10:37 pm #50076
Ok, heres a plan that crossed my mind today:
I love the FTX bullets, not just because they work in lever action rifles, but by virtue purely of their design and precision.
What if I loaded those up over a max charge of CFE BLK? According to Hodgdon, that delivered 1887 FPS from a 16″ barrel. Subtracting 200fps gives 1687, which appears to render 1000ft-lb+. As a bonus, they are designed to work at lower velocities, and the shape of the ogive will put it closer to the lands. I may have to try that!
April 11, 2018 at 9:49 pm #50075
Not familiar with that bullet, you can seat out real far to get case space but BT reduces powder space. I couldn’t get enough powder under a 165 amax, 55 was Ok.
April 12, 2018 at 10:34 am #50080
FTX is harder jacket than Amax but still has the BT. Have you looked at 170 interlock? Flat base and fills the throat well. BC is poop but hey, short distance anyway. The reason I went with the RD style for the pistol. Used a 185GC version (softer alloy) on a sprinting pig. I did find blood on a johnson grass blade – took a shot ~50 and friend said he thought it ducked – never found it. Then we shot steel @50 with the H 3031, it works VERY well (H110). Barrel is 10.5 KAK with pistol gas turned almost OFF.
April 14, 2018 at 9:00 am #50107
I’ve been doing some research and running ft-lb calculations based on available load data. It seems that the 150 grain bullets are able to deliver the heaviest hit at 1400 ft-lbs.
However, that 180 grainer over 4198 was pretty awesome, and uses a powder that I stock already. Seems the three best powders for this caliber are the new CFE BLACK, Accurate Arms 1680, and LilGun. All of which cannot be sourced locally (at least not for a reasonable price) so I’m tempted to stick with what I’ve got.
I like the 170 flat based idea. I can drill a HP in it to get it to open at low velocity. The 168 Amax also sounds like a match made in heaven, but I lose energy with these, and it puts me in a powder that’s hard to get (CFE BLACK, LilGun).
April 14, 2018 at 1:43 pm #50108
That’s why I run the 143gr PB @ 2100. 3.5″ drop & 1k ft-# at 200. From the carbine, pistol should be great to 100. I don’t use lilgun, supposed to burn real hot.
April 14, 2018 at 10:04 pm #50113ArtfulParticipant
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With the lighter weight I’m running 5744 with 180 grain and up I use 1680/WCC680 surplus.
April 15, 2018 at 9:09 pm #50121Rattlesnake CharlieParticipant
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Goodsteel, if you are interested, I have some molds you can use to try some different bullets in the range you are looking for:
NOE 311465, 122 RN-HP Loverin, 5 cavity, all GC, one cavity HP
MiHec MP 311410, 130 gr RFN HP, 4 cavity, all GC
MiHec MP 312-159 Soupcan, 159 gr solid / 154 HP, 4 cavity, all GC
NOE 312-160-RFN, 4-cavity, the Ed Harris design for 7.62×39
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