Mk319 SOST or Hornady TAP 155gr AMAX?

[ABNAK]

For my Galil Ace with a 16" barrel. Looking for the best combination of accuracy (out to 600m), penetration of intermediate barriers, and terminal ballistics.

Mk318 came highly recommended in 5.56 so does it's big brother, the Mk319, make the cut? Or is the 155gr AMAX just a better all-around bullet?

[mic2377]

The only thing I was think that the MK319 would do better would be barrier penetration. I will say from personal experience on game though that the Amax in both 155 and 168 is an extremely lethal bullet on game at both middle and long range, even at carbine velocities. The gel tests on Hornsby's website for the TAP say it all.

[ABNAK]

The only thing I was think that the MK319 would do better would be barrier penetration. I will say from personal experience on game though that the Amax in both 155 and 168 is an extremely lethal bullet on game at both middle and long range, even at carbine velocities. The gel tests on Hornsby's website for the TAP say it all.

Correct me if I'm wrong but isn't the Hornady TAP designed for intermediate barrier penetration too?

[vicious_cb]

Correct me if I'm wrong but isn't the Hornady TAP designed for intermediate barrier penetration too?

No, the AMAX is a thin jacketed match load that will fragment. While the rear copper slug of the mk319 will over penetrate. They do not fill that same role at all.

[ABNAK]

No, the AMAX is a thin jacketed match load that will fragment. While the rear copper slug of the mk319 will over penetrate. They do not fill that same role at all.

Hornady's website mentions auto glass deflection in it's description of the TAP AMAX:

The 155 gr. A-MAX® TAP Precision® cartridge offers match accuracy with a high ballistic coefficient to provide superior long range performance and accuracy. This bullet performs very similarly to the 168 gr. A-MAX®bullet, providing controlled and impressive soft tissue expansion without over penetration. The 155 gr. A-MAX® penetrates glass with minimal deflection and serves as a great alternative to the 168 gr. A-MAX® for Law Enforcement duty applications.

Not being argumentative, just trying to decide between the two as to which best meets my desired specs (see OP).

[vicious_cb]

Hornady's website mentions auto glass deflection in it's description of the TAP AMAX:

The 155 gr. A-MAX® TAP Precision® cartridge offers match accuracy with a high ballistic coefficient to provide superior long range performance and accuracy. This bullet performs very similarly to the 168 gr. A-MAX®bullet, providing controlled and impressive soft tissue expansion without over penetration. The 155 gr. A-MAX® penetrates glass with minimal deflection and serves as a great alternative to the 168 gr. A-MAX® for Law Enforcement duty applications.

Not being argumentative, just trying to decide between the two as to which best meets my desired specs (see OP).

Deflection refers to the amount of POI change after encountering a barrier. Like how a bullet tends to hit low when shooting into a vehicle through the windshield, not the terminal effects after encountering said barrier. Basically treat the amax like you would an OTM. If barriers are a concern you're better off with a bonded soft point.

[MisterHelix]

For my Galil Ace with a 16" barrel. Looking for the best combination of accuracy (out to 600m....

Seems to me, if a 600m range is specified, I would not be looking a 130 grain projectile.

I would think a Hornady SST, or Nosler Accubond, or a similar bonded projectile in the 168-175 class would be more appropriate.

[LDM]

Velocities out of a 16" 308 call for some thought provoking trade-offs in bullet selection for terminal effects and penetration.
I shoot a 16" FAL and typical reports of chronograph muzzle velocities are about 2550 fps for a 150 gr bullet. So at 200 yards, velocity is about 2150. At 300 yds, 1960 fps. And at 500 yds, 1600 fps. Would think a 16" Gallil is similar.
So for terminal effects, bullet construction is a big consideration. I have been shooting 150 gr Nosler Accubonds. I am giving this choice of bullet some hard thought.
Something I have recently focused on is the velocity thresholds for expansion. And moreover, take for instance the photos of Accubond bullets expansion at different velocities on the Nosler website. Just looking at those photos, on the surface this bullet is good down to 1800 fps. However if those expansion examples are after penetration of ballistic gel (as I assume they are), then what we are seeing is expansion after penetration of "meat" (which gel simulates). Lung for example is nowhere as dense as meat, so I think passage through lung would not open expansion as quickly.
So in regard to terminal effects, a lighter construction bullet like the 155 AMAX might be appropriate for longer range. The 155 AMAX is noted for its accuracy.
And a lighter weight bullet, like a 130 gr cup & core bullet or the 319, with faster velocities are probably better for short and intermediate range (say up to 200 yds). And if I understand the objectives that drove the design of the 319, it was for terminal effects out of a 16" 308 at short and intermediate range.
I am starting to lean toward the lighter, faster bullet approach as 200 yards covers my particular needs.
The 155 AMAX might (?) be a good compromise between long and intermediate.
I am still puzzling over this in my mind, so will be interested in comments and critique.

[ABNAK]

Velocities out of a 16" 308 call for some thought provoking trade-offs in bullet selection for terminal effects and penetration.
I shoot a 16" FAL and typical reports of chronograph muzzle velocities are about 2550 fps for a 150 gr bullet. So at 200 yards, velocity is about 2150. At 300 yds, 1960 fps. And at 500 yds, 1600 fps. Would think a 16" Gallil is similar.
So for terminal effects, bullet construction is a big consideration. I have been shooting 150 gr Nosler Accubonds. I am giving this choice of bullet some hard thought.
Something I have recently focused on is the velocity thresholds for expansion. And moreover, take for instance the photos of Accubond bullets expansion at different velocities on the Nosler website. Just looking at those photos, on the surface this bullet is good down to 1800 fps. However if those expansion examples are after penetration of ballistic gel (as I assume they are), then what we are seeing is expansion after penetration of "meat" (which gel simulates). Lung for example is nowhere as dense as meat, so I think passage through lung would not open expansion as quickly.
So in regard to terminal effects, a lighter construction bullet like the 155 AMAX might be appropriate for longer range. The 155 AMAX is noted for its accuracy.
And a lighter weight bullet, like a 130 gr cup & core bullet or the 319, with faster velocities are probably better for short and intermediate range (say up to 200 yds). And if I understand the objectives that drove the design of the 319, it was for terminal effects out of a 16" 308 at short and intermediate range.
I am starting to lean toward the lighter, faster bullet approach as 200 yards covers my particular needs.
The 155 AMAX might (?) be a good compromise between long and intermediate.
I am still puzzling over this in my mind, so will be interested in comments and critique.

That's what I have been mulling over too. 600m isn't "long range" per se, so at a minimum I'd like to have a round that would be A) accurate and B) have relatively decent terminal effectiveness at that range. Yes, the 16" barrel must be factored in when deciding on bullet weight, as the 168gr weights on up would be too slow out of that short of a barrel to have terminal effects at that range like I'd prefer.

While I am sold on Mk318 for 5.56mm, I think I'm leaning towards the 155gr AMAX TAP load in .308.

[mic2377]

I think it important to understand projectiles like the Amax work different than something like Accubond or other bonded bullets designed for 100% weight retention. The Amax sheds some of its weight in a fragmenting fashion. However it does this down to a fairly low velocity, which helps ensure good tissue damage even without hydrostatic shock. The problem is that unless it has adequate sectional density penetration is lacking. The 155 and 168 in my mind strike a pretty good balance for the 308, especially shorter barrel variants.

I am fairly sure the Amax has a fair amount better BC than the SOST too. I also shot some of the 130's out my 300 BLK - while it was only able to make ~2200 fps, even at point blank range expansion was highly underwhelming.