TAC-TV comparison...

[El Wray]

Did anyone catch the recent episode of Larry Vicker's TAC-TV where he compares the 300 BLACKOUT to the 5.56mm and the 7.62x39. The results of his testing were pretty predictable. His conclusion was that the 300 BLACKOUT was adequate out to 150 yds with the right bullet. I couldn't help but think that there is a round out there chambered for the AR15 platform that would've outperformed all of those rounds in the tests he performed... the 6.5 Grendel.

[Whelenon]

Ya I saw it and had to laugh. The 300 Blackout is definitely a short range cartridge. I didn't catch were the guns were zeroed at but at 200 the blackout was dropping 14-16". The Grendel would have smoked all three calibers.

The problem with most of the gun related shows is they pretty much only hype there sponsors. Although, on Guns&Ammo I did hear Craig Boddington recommend the Grendel for an AR Hunter, course he mentioned the 6.8 in the same sentence.

[mongoosesnipe]

It's really not a comparison at all the blackout is a sammi version of the 300 whisper which is designed as subsonic cartridge ideal for suppresed use not really designed to shoot at targets 1000 yards away a fair comparison is to compare it to 9mm which is the actual compition for the cartridge it is designed and used in place of suppressed sub machine guns while giving the option of accurately engaging targets to 200 plus yards well passed the effective range of subsonic 9mm

[Dacapster]

Don't put this on 300blktalk because they think that round should do .5 moa out to 300 yards and knock over an Alaskan Moose.
I have one and love mine but know it's limitations.

[Hooz]

I watched it, and even though I know the limitations of my 300BLK (10.3" SBR AR and a 16" bolt action), I thought the tests LV did were laughable. The drop was expected, but he didn't even really zero the guns before he started. The 5.56 was shooting dead-on at his "zero" range (25 yards?), the 7.62x39 was 1-2" low at the same range and the 300BLK was already 2-2.5" low... and then he used different aiming points on the targets at extended ranges. I kind of expected more from LV.

[Hooz]

Okay. I got curious after watching the show and reading all the debate, so I ran some numbers myself. I went to Hornady's website and pulled-up a representative factory load for each caliber that they tested on TacTV. I used a 55gr 5.56 NATO round, a 110gr 300 Whisper round (Hornady doesn't load 300 BLK proper, but Whisper is close enough for what I'm doing) and a 123gr 7.62x39 round.

Using the information on the Hornady website, I plugged all the numbers in to a ballistic calculator to calculate the drop for each round from 0-300 yards, sighted-in at 100 yards with a 2.5" sight height.

I also used the same numbers to calculate a the Maximum Point Blank Range (MPBR) and appropriate sight-in distance for each round on an 8" target. For those not familiar with MPBR, using an 8" target, the MPBR is the distance to which the bullet never passes more than 4" above or below the point-of-aim. If the MPBR is 250 yards, that means you can hold dead-on from 0 to 250 yards and (theoretically) never have a shot outside of your 8" circle.

Here is what I came up with for each of the three rounds...

Hornady 110gr V-Max (300 Whisper, 16" Barrel)
2375fps - 110gr - .290 BC - 100 yard zero - 2.5" sight height
MPBR (8" Target) - 258 yards - Sight-in 3.62" high @ 100 yards

Hornady 55gr GMX (5.56 NATO Superformance, 20" barrel)
3130fps - 55gr - .270 BC - 100 yard zero - 2.5" sight height
MPBR (8" Target) - 327 yards - Sight-in 2.86" high @ 100 yards

Hornady 123gr SST (7.62x39mm Steel Case, 20" barrel)
2350fps - 123gr - .295 BC - 100 yard zero - 2.5" sight height
MPBR (8" Target) - 256 yards - Sight-in 3.63" high at 100 yards

I have seen people asking how the sight-in ("zero") distance relates to "bullet drop", so I charted it all out as a sort of visual aid. On the graph below, you'll see each round's trajectory plotted with a standard 100 yard sight-in distance. I also plotted each round with the sight-in distance needed to achieve its MPBR on our proverbial 8" target.



Click here to see the actual numbers I used for this chart.

[bwaites]

The .300 AAC was specifically designed to match the supersonic characteristics of the 7.62x39 round, and the graphs emphasize that.

The strengths of the .300 AAC are two:

1) Great subsonic performance in the AR platform.
2) Great feeding in the AR platform whether sub/supersonic. This was the real purpose of the round, since getting 7.62x39 rounds to feed reliably in the AR is tough.

One of the issues we face with the Grendel and subsonic shooting is that we have more powder capacity, but we don't have a 200+ grain bullet. The .300 AAC cycles because it has such heavy bullets.

[Hooz]

Because I am bored at work and I have a touch of OCD, I played with the ballistics a bit more to see if I could figure out why LV's bullet drop was so out of whack from what I see with my 300 BLK guns.

In the show, when he "sighted-in" the 300 BLK it was hitting 2-2.5" low at whatever distance he was shooting. Now, I'm not sure, but I'm going to assume he was sighting-in at 25 yards. Figuring a sight height on an AR around 2.5", and the 300 BLK shooting 2.5" low at 25 yards, I took the same Hornady Whisper load that I used above and ran it back through the calculator.

Here are three different trajectories. The first "Theoretical Trajectory" was based on what LV shot on the show, the second trajectory is figured with a 100 yard zero and the last is shown with the 222 yard zero listed in my last chart (to achieve MPBR on an 8" target).



As you can see, the "Theoretical Trajectory" matches up pretty well with what LV experienced on the show. It also explains why his numbers are so different than mine, as I use a 100 yard zero (50 yards for subs).

[txgunner00]

The .300 AAC was specifically designed to match the supersonic characteristics of the 7.62x39 round, and the graphs emphasize that.

The strengths of the .300 AAC are two:

1) Great subsonic performance in the AR platform.
2) Great feeding in the AR platform whether sub/supersonic. This was the real purpose of the round, since getting 7.62x39 rounds to feed reliably in the AR is tough.

One of the issues we face with the Grendel and subsonic shooting is that we have more powder capacity, but we don't have a 200+ grain bullet. The .300 AAC cycles because it has such heavy bullets.

We have proven cycling subs can be done in the Grendel with 160 grain bullets but I doubt they will work in commercial loadings. Too many variables and way too sensitive to barrel length, gas system, buffer weights, etc.

[bwaites]

We have proven cycling subs can be done in the Grendel with 160 grain bullets but I doubt they will work in commercial loadings. Too many variables and way too sensitive to barrel length, gas system, buffer weights, etc.

And a lot of time and effort!

We need a heavier bullet.

I applaud those of you who have made it work!

I really should get some 160's and see how they cycle in my 28" !

[Whelenon]

Hooz,
What is the MPBR of the Hornady 123 Grendel round as compared to your data above?

[Hooz]

Hooz,
What is the MPBR of the Hornady 123 Grendel round as compared to your data above?

2350fps from a 16" barrel and .510 BC would be a 274 yard MPBR on an 8" target. Zero 3.54" high at 100 yards.

2620fps from a 24" barrel would be 304 yards. Zero 3.25" high at 100 yards.

[Variable]

And a lot of time and effort!

We need a heavier bullet.

I applaud those of you who have made it work!

I really should get some 160's and see how they cycle in my 28" !

Amen! I'd like to see a 180 grain bullet. I have gotten close with the 160 Hornady, but I need more weight for my 10.5" barrel. I could tinker with the gas system, but as it runs great as is with normal ammo, I've decided to leave it alone for now. I was going to get an adjustable block, but no one makes exactly the one I want.

A jacketed 180 grainer like the current 160 Hornady would likely be just the ticket.

ETA: Are there any custom bullet makers out there that could make us a small batch of 180gr. jacketed RN's for testing purposes to see if it would be feasible? If they could be had for a reasonable price, we could order a small batch and then divvy them up for testing.... I'd be willing to pay around say a buck a pop(?) for some 180 pills in a small batch if we shared them. Maybe 50 bullets to each tester? I have no idea if that is feasible though....

I'd like to see something heavy enough to run well through the Grendel with Trail Boss powder for subsonic loads and still cycle. That would make a nice safe recipe for even beginners to load up with. If we had something like that and it ran good through the 10.5" tubes, then every other barrel length would be easy from there on out (IMO).

[Grimmy]

I have a super sonic 300 blk I run on a tacticl course with a fifty yard zero I hold on the neck portion of the silohettes on the course and I make solid mid section hits in the torso of the target. I know the round has it's limitations but at 200 and under it rocks those steel targets and there's alot more noticable ring to the target. And my Grendel really rocks them but it's heavy and isn't easy to use on a fast moving course. They both have a use in the tactical shooting theater wouldn't give up either. I have two 5.56 one 6.8 one 300blk a Grendel and two M1a's they all have their strong points and weakness My one M1a is in a Troy's Battle stock with a 16inch Socom barrel it kicks butt on the course buy is brutal on recoil and heavy.

[Deer Hunter]

I watched the episode and like most of you I expected the same results. Im not to impressed with the 300 Blackout especially compared to our Grendel, bottomline it cant compete. I was however suprised at the ballistic gel test where the 5.56 looked to kick the crap out of the Blackout and the 7.62x 39.