.300 AAC Blackout - 'Enabling' Thread (Mags, ammo, optics, barrels, etc.)

[Grey]

Not to be a....well....an “appendage”, but let’s just step back here a bit huh? Using the data listed in the above post (which seems legit compared to my own data which shows 1300fps@ 350yds out of an 8” barrel) how are you going to articulate that 200yd+ defensive shot?

“Looking at him through my spotting scope on 10x, he appeared to be a threat.”

If we’re talking four legged critters, different story, although even at 200yds, I’d be inclined to give whatever creature it was a wide berth and continue on my way. Except coyotes. I’d still shoot them...

I just copy pasted from the website. The point was that at 100 yards you're over 1500 fps. The last question is what velocity do the GMX rounds expand at? And as I said earlier in my post no one needs a shot over 50 for this specific purpose.

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[OlongJohnson]

The Barnes can be launched at as low as 1300fps from the muzzle and still expand and penetrate, which means when it comes out of a Rattler at ~1900'ish it will be fine for pretty much any conceivable distance.

I don't know what the GMX needs velocity wise to properly expand and penetrate. I would guess it's in the same vein as the Barnes, given the similarity in construction and purpose.

Let's keep what we're talking about straight.

The Barnes TAC-TX expansion threshold is more like 1300-1350 at impact, not the muzzle, and the expansion can be pretty minimal (just the tip) at those speeds.

I would expect the GMX to be more like the Barnes TSX and TTSX, which want to be in the range of 1800 or faster to initiate expansion. If you get down to 1500-1600 FPS at impact, they likely might as well be FMJ or solids.

[RevolverRob]

Let's keep what we're talking about straight.

The Barnes TAC-TX expansion threshold is more like 1300-1350 at impact, not the muzzle, and the expansion can be pretty minimal (just the tip) at those speeds.

I would expect the GMX to be more like the Barnes TSX and TTSX, which want to be in the range of 1800 or faster to initiate expansion. If you get down to 1500-1600 FPS at impact, they likely might as well be FMJ or solids.

Fair.

I was thinking more like, "If I launch this thing at 1300fps at the muzzle and hit something across the room - I'll get some expansion." Basically meaning no real velocity loss.

And yea...maybe just the tip.

Tac-TX seems to have kind of a sweet spot where you can get full expansion and penetration with an impact velocity as low as 1500 fps. When you throw it out of a Rattler at close to 2000fps, you'll be well within the sweet spot inside of 100y.

That's why it's 'the one'. If the 110 GMX performs in a similar range as the Tac-TX - it would be awesome. If it doesn't...then you're back to one solution for the Rattler the Tac-TX.

If you're running an 8" gun, you can use Barnes, Hornady, maybe even the Gold Dot (though I'm still skeptical that the 150-grain GD will perform well at anything below 2000 fps)

[entropy]

From what I have heard, the GMX indeed needs a 1800-2000fps threshold for reliable expansion. Both the 110 and the 120gr Barnes black tips have worked well for me. A number of years back, I bought a bulk of both as pulldowns from American Reloading. The 120s were actually boat tails, and I had hoped I would be able to squeeze a bit more accuracy from them. I could not. I ended up using those as blasters while keeping the 110s for defensive loads.

Somewhere around here (I know I kept it) was a 110gr I just happened to recover from a softer clay/sand backstop. The recovered distance was about 150yds and the thing looked like a damn archery broad head. The petals had peeled back nearly perfectly with only a bit of curl back, and the damn thing looked like something out of a science fiction movie. I was pretty impressed.

Had I known better, I would have ordered every single one of those things they had in stock. Out of about 800, I had maybe only 30 or so that were damaged in the form of cracked tips. Even those I shot.

[Norville]

I found this. 8.5” barrel, far from calibrated gel in a controlled test but seems to work.

https://youtu.be/yme5HTP5TgU

[RevolverRob]

I really want to see the Sig 120-grain SBR round in gel and through an intermediate barrier and see how it does. That's the other factory load I'm interested in besides the two Tac-TX loads.

Actually, the Hornady 135-grain FTX might be kind of interesting. Though, I'm not sure that isn't just the same bullet from the .30-30 leverevolution round loaded in a .300BO case. Well...I guess not I just went and looked and Leverevolution is currently 140-grain and 160-grain varieties. Though, I could swear there was a 135 at some point. Hmm, apparently Hornady is saying expansion of the FTX can be initiated as low as 1550 - but apparently penetration suffers a lot. Still going to have kind of a tight window in the short guns.

[PearTree]

How reliable is the expansion for the Hornady at lower velocities?

That's the thing about the Barnes - it has a lower threshold of 1300fps - And when shooting them out of a Rattler, most loads are in the 1800-2000fps at the muzzle.

It was my understanding gmx expands down to 1800fps. Where did you find 1300fps expansion for the Barnes? Everything I have seen says 1500-1600. Barnes also clarified the FPS figures include partial expansion, which I find a little misleading. Maybe @DocGKR can weigh in?
I don’t have a rattler so I have no clue what velocities 110 gmx would have out of it. All of the Hornady testing I have seen goes as low as an 8 inch 1/7 barrel.

[ranger]

I wonder if the various 110 grain Varmint projectiles will be effective at 300 BO speeds from short barrel. They shoot great and very accurately out of my PSA 7.5 inch upper. Since Barnes etc. are sold out, I loaded up the 110 varmints. They may not go the FBI depth but I bet they make a large hole at the depth they do go

[RevolverRob]

It was my understanding gmx expands down to 1800fps. Where did you find 1300fps expansion for the Barnes? Everything I have seen says 1500-1600. Barnes also clarified the FPS figures include partial expansion, which I find a little misleading. Maybe @DocGKR can weigh in?
I don’t have a rattler so I have no clue what velocities 110 gmx would have out of it. All of the Hornady testing I have seen goes as low as an 8 inch 1/7 barrel.

You know, it's just a number I've seen on the interwebs. So, I fired off an email to Barnes with the follow questions regarding the 110-grain Tac-TX in .308" diameter:

1) What is the velocity performance envelope for the Tac-TX in this diameter?

2) Is the lower number (minimum) enough to induce full or partial expansion?

3) Is the lower number (minimum) enough to provide substantial penetration? (I.e., greater than 12” in ordnance gelatin).

I'll report back what they tell me.

[RevolverRob]

I wonder if the various 110 grain Varmint projectiles will be effective at 300 BO speeds from short barrel. They shoot great and very accurately out of my PSA 7.5 inch upper. Since Barnes etc. are sold out, I loaded up the 110 varmints. They may not go the FBI depth but I bet they make a large hole at the depth they do go

This piece from Outdoor Hub might be of interest to you:

https://www.outdoorhub.com/stories/2...al-ballistics/