300 BO and Supersonic 190 SUB X

[bluejay75]

Greetings Gents,

I have been running the 180 SST with 18.5 CFE BLK at 1600 fps. I was wondering if there’s anyone out there running the sub x at max velocity.

Should make a very effective killer out to 200 yards or so.

Any comments welcome.

Bluejay

 

[bluejay75]

 

[huntnh]

I wonder how good they’ll stay together?

 

[db2000]

Here’s a link with some ballistic gel and ladder testing with A1680

190 gr Sub-x subsonic and supersonic loads - Page 3 » 300BlkTalk

 

[Ape_Factory]

For the life of me I cannot get those Sub-X bullets to feed/chamber reliably in my AR. I desperately want them to work mostly because I have about 600 of them, LOL. Every time I do a test round, various lengths, even factory ammo length, the bullet's nose looks pretty beat up. I have a few boxes of the SST's in 180, are they really expanding at that velocity?

 

[bluejay75]

For the life of me I cannot get those Sub-X bullets to feed/chamber reliably in my AR. I desperately want them to work mostly because I have about 600 of them, LOL. Every time I do a test round, various lengths, even factory ammo length, the bullet's nose looks pretty beat up. I have a few boxes of the SST's in 180, are they really expanding at that velocity?

Yes. The nose is very soft. As soft as an ELDM.

 

[Yondering]

Yes. The nose is very soft. As soft as an ELDM.

Based on testing in what media? Since you said "should be an effective killer" I'm guessing you haven't killed anything with them yet, so no meat results? If you're testing in sand or something like that, you're probably seeing results that don't line up with what happens in meat. This is why sand testing sucks.

In my experience, an ELDM doesn't have a particularly soft tip and doesn't expand at those speeds from the Blackout. I'd be really surprised if the SST did either. Talking about expansion in live meat, and not just what they do when hitting bone, or inappropriate test media. There aren't many 30 cal rifle bullets that expand significantly below 1600 fps; the Barnes110gr black tip does for sure, and of course the various specialty subsonic bullets, and Nosler's ABLR line does as well although it's kind of toeing the line right there. But the ELDM (and other SST bullets I've used) seem to have a lower limit around 1800-1900 in my experience.

I really don't see the point in pushing heavy bullets to medium-slow speeds in the Blk though. It's a better killer with the 110-125gr class and plenty of proven good bullets (like the black tip mentioned above, or the 125 NBT, both of which expand well at reasonable ranges and penetrate deeply). Or just the typical subsonic specialty bullets at subsonic speed; some of those may be interesting pushed faster but you'll likely find them shedding noses and/or petals, which isn't completely a bad thing but you need to be aware of what they do.

 

[bluejay75]

Very good points sir. I typically can’t speak for expansion as nearly every deer that I have shot in the past few seasons at 125 yards or less have been neck shot. But I will run the 178 ELDm and x at 1600 and see what they look like in soft packed newspapers and report back.

 

[JBoomhauer]

For the life of me I cannot get those Sub-X bullets to feed/chamber reliably in my AR. I desperately want them to work mostly because I have about 600 of them, LOL. Every time I do a test round, various lengths, even factory ammo length, the bullet's nose looks pretty beat up. I have a few boxes of the SST's in 180, are they really expanding at that velocity?

Same here.

Getting very frustrated with them. Have tried just about everything and cannot get them to cycle subsonic.

 

[Yondering]

Same here.

Getting very frustrated with them. Have tried just about everything and cannot get them to cycle subsonic.

Feeding issues, or cycling issues? If it’s a cycling issue, try using AA1680 or CFE BLK. If those don’t work, your rifle probably has the gas turned down too low.

For feeding issues, try seating deeper, and also smooth out the sharp edges on the feed ramps. You might want to make sure you’re using 300 Blk mags too and not 5.56 if you’re seated longer; it won’t make a difference with just a couple rounds in the mag but if you’ve got a full mag that inner rib can make the rounds go pigeon toed in the mag and have feed issues.

 

[JBoomhauer]

Cycling.

Bought as a nighttime coyote subsonic rig, so super isnt a huge concern for me.

Tried a few powders up to 1100fps with no luck including 1680 and CFE BLK.

Talked to a friend last night that knows way more about this stuff than I do. 16” pistol gas barrel. We agreed it sounded under gassed. I opened the port up from .105 and finally got function but no lock back at .120.

Going to run with it like this for a little bit and see if it loosens up and starts locking back. If not ill do the full .125 and get an adjustable block to run supers.

Sounds like a ton of gas, but apparently its what this setup needs.

These actually feed better for me with the 20 rd 5.56 lancers vs the 300 mags.

This thing has been frustrating.

 

[Yondering]

Cycling.

Bought as a nighttime coyote subsonic rig, so super isnt a huge concern for me.

Tried a few powders up to 1100fps with no luck including 1680 and CFE BLK.

Talked to a friend last night that knows way more about this stuff than I do. 16” pistol gas barrel. We agreed it sounded under gassed. I opened the port up from .105 and finally got function but no lock back at .120.

Going to run with it like this for a little bit and see if it loosens up and starts locking back. If not ill do the full .125 and get an adjustable block to run supers.

Sounds like a ton of gas, but apparently its what this setup needs.

These actually feed better for me with the 20 rd 5.56 lancers vs the 300 mags.

This thing has been frustrating.

Something isn’t right there, and I don’t think it’s the bullet at fault. A 16” with pistol gas shouldn’t need a gas port that big. I’d be looking for gas leakage or restriction somewhere in the system - misaligned gas block, loose gas key, worn rings, etc. If you’ve fired a bunch of lead bullets the gas tube or key may be partially blocked up, or even the carrier itself.

Or are you using an extra heavy buffer and/or spring maybe? A standard carbine buffer and spring work well for the 300.

 

[JBoomhauer]

Have tried Giessele 42 spring and buffer in case it was overgassed and overrunning, Standard spring and buffer, JCS SCS Standard.

Tried 2x FA BCGs Of different manufacturers and a semi.

Tried multiple gas blocks and new gas tubes.

You name it, ive tried it.

 

[Yondering]

You name it, ive tried it.

Seems like a common trend with some guys, to say there’s a problem but then resist any input to figuring it out.

If you’d really tried everything, you’d have figured out the problem. But here you are, with a rifle that obviously has something wrong, and planning on modifying the wrong thing instead of fixing it right.

 

[JBoomhauer]

The only 2 variables left were the upper, which is a BCM and the barrel which is a wilson.

Barrel is factory dimpled for gas block. Checked alignment via borescope and by removing and visually looking at the carbon circle. Checked for port size and burrs with gage pins.

Checked and replaced gas blocks and gas tubes.

Tried multiple spring and weight combinations.

Tried different proven lower.

Checked and gaged BCG, Swapped with another proven BCG, Swapped with another proven semi auto BCG. Did not try a lightweight specialty BCG.

Checked for gas tube alignment in upper and made sure BCG fell freely with multiple gas tubes.

Loaded multiple powders up to supersonic speeds.

Not sure what else I could have tried.

Not trying to resist input at all.

Seriously let me know what I should have tried that I did not.

 

[bluejay75]

Very stable load and the most accurate of what I tried. These were loaded to full magazine length which barely compressed at max charge from the Sierra manual so I kept going as there was space in the case. This load shot barely over an inch and the velocities are from a 10.5 in pistol. IMO this is like having a 357 magnum/ max AR with better BC bullets.

 

[bluejay75]

18.0 CFE BLK

 

[bluejay75]

Still could hear powder shaking in this load.

 

[Jordanledwards1]

Cycling.

Bought as a nighttime coyote subsonic rig, so super isnt a huge concern for me.

Tried a few powders up to 1100fps with no luck including 1680 and CFE BLK.

Talked to a friend last night that knows way more about this stuff than I do. 16” pistol gas barrel. We agreed it sounded under gassed. I opened the port up from .105 and finally got function but no lock back at .120.

Going to run with it like this for a little bit and see if it loosens up and starts locking back. If not ill do the full .125 and get an adjustable block to run supers.

Sounds like a ton of gas, but apparently its what this setup needs.

These actually feed better for me with the 20 rd 5.56 lancers vs the 300 mags.

This thing has been frustrating.

You ever try any accurate 11fs? It yields higher pressures at sub loads and cycles my Daniel defense pdw suppressed just fine. It shoots 190 subx subsonic very accurately at 9.4gr and 2.11” COAL. Berrys 220 spires like the same charge.

If you gave up I’d be glad to take the 190subx off your hands

 

[Farmerbrown32]

Anybody wanna sell a box or two of the sub x? Id like to try some