5.56 Water Expansion Testing; 55/70gr GMX, 62gr TBBC, 55/64/75gr GDSP

[BufordTJustice]

Did some water jug testing today. Please do your own research about this as it is NOT a tissue simulant. However, it is good for comparative purposes. All shots delivered from my 16" BRT Optimum 1:8 5R duty rig except for the last shot, 6) Speer 55gr GDSP, which was from my buddy’s 16" middy 1:7 BCM CL’d upper. All shots were fired from approximately 15 yards, without a chrono, at 80 degree F ambient temperature. Rounds were tested today in this order:

1. Hornady 55gr Superformance GMX 5.56 NATO pressure

2. Hornady 70gr GMX TAP (only made in 5.56 NATO pressure)

3. Federal XM556FBIT3 62gr TBBC (5.56 pressure FBI Load)

4. Speer 64gr GDSP (.223 pressure)

5. Speer 75gr GDSP (.223 pressure)

6. Speer 55gr GDSP (.223 pressure)

A half pallet was used. 5 1-gallon water jugs were used for each shot. Penetration and effects description:

1. 55gr GMX NATO Superformance. fully split the first two jugs; just literally ripped them completely in half. Heavily damaged the 3rd jug. Punctured and was captured in the 4th jug.

2. 70gr GMX TAP. fully split the first two jugs. Same as 1). Partially split the third jug (heavily damaged; more so than 1 or 3). Bulged and partially seam-split the 4th jug. Penetrated 4th AND 5th jugs and was captured in the 5th. 5th jug was flipped over onto its back.

3. 62gr XM556FBIT3. fully split the first two jugs; just literally ripped them completely in half. Heavily damaged the 3rd jug. Punctured and was captured in the 4th jug.

4. 64gr GDSP. fully split the first jug with a connecting piece of plastic on the bottom. Partially split the second jug. Captured in the third with little to no damage.

5. 75gr GDSP. fully split the first jug with a connecting piece of plastic on the bottom. Marginally more damage to the second jug than the 64gr above. Captured in the third jug with same amount of damage as above.

6. 55gr GDSP. Fully split the first jug with a connecting piece of plastic at the bottom. Bulged the second jug and dented the back wall, but was captured in the second jug.

General observations:

The effects from the 70gr TAP GMX were notably better than either the 55gr GMX or the vaunted 62gr TBBC. Another shot was taken with a 165gr Remington Hog Hammer TSX from a 16" Faxon barrel in an AR10 I built for my buddy. Not super dissimilar performance from the 70gr TSX for the first 3 jugs. However, no slug was recovered.

Both the 62gr XM556FBIT3 TBBC and the 55gr GMX NATO Superformance performed identically. Which is to say that they were both very impressive. They were head and shoulders above the GDSP rounds in terms of their effects on the first three jugs; both penetrated into the 4th jug (both of them knocked the fourth jug over onto its back side). It was even clear to my terminal ballistics neophyte buddies that the first three rounds were clearly in another league compared to the Gold Dots… and that their increased price did indeed net observably superior performance in both penetration depth and terminal effects on the first three jugs.

The over-expansion of the lighter 64 & 55gr GDSP bullets was easy to see, with this acutely affecting the 55gr. Though, this may make them particularly well suited to SBR use.

The 75gr GDSP had solid performance and was clearly the strongest recoiling .223 pressure round tested. Again, without a chrono reading I cannot comment intelligently on the actual velocity. But it felt strong.

Pictures of expanded rounds in next post…

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[BufordTJustice]

1. 55gr GDSP
2. 64gr GDSP
3. 75gr GDSP
4. 62gr TBBC XM556FBIT3
5. 55gr GMX NATO Superformance
6. 70gr GMX TAP NATO

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[BufordTJustice]

Conclusions:

This really solidified my well researched decision to employ caches of 55/70gr NATO GMX and 62gr XM556FBIT3 as my primary SD/HD/Hunting rounds. It also verified my experiences in the field hunting hog with these three; simply excellent results even with questionable shot placement due to rushed shots; with the 70gr GMX being essentially peerless among rounds I’ve used and tested.

It also shows that the 64gr GDSP continues to be a value leader in bonded soft point ammo and for good reason… and that the 75gr brings possibly the best Gold Dot offering to the table as long as a large premium isn’t paid over 64gr GDSP. The 55gr GDSP could be an excellent SBR option for 13.7" and shorter barrels; however, it was clearly overtaxed at the impact velocity seen from a 16" barrel. It hung together admirably and did not fragment, but the penetration was VERY shallow.

My last testing of a 124gr +P Speer 9mm Gold Dot HP from a G19 resulted in the round being recovered in the third jug with an observable dent at the rear of the jug. I neither have a need nor feel comfortable recommending the 55gr GDSP for use in barrels longer than 13.7"-14.5".

Next testing is from my 11.5" Sionics SBR.

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[WS6]

Ive had 70gr gmx fail to expand. This was shot broadside (far back, yes, i was not the shooter), the bullet made a punctuate entrance, tumbled, and exited as best i can tell. Here are the pictures. Fired from a 16.1 AR. The only thing i can fathom that would cause such wounding and deviation from 90* broadside is a tumble and failure to expand. Not pictured, but the inside of the ribcage entrance looked the same as the outside. Tiny hole.

[vicious_cb]

Water displacement and ripping of juggs mostly captures the effect of temporary cavitation of which both DocGKR and Fackler are hesitant to apply significant wounding potential to TC. Hence I wouldnt put much stock on how much “explodiness” of water jugs correlates to terminal performance. Remember, varmint bullets are probably the most dramatic water jug exploders but there is no way I would use them as a duty load.

[ALCOAR]

Good test brother. Well laid out, and the pics are nice. One can gain invaluable knowledge when witnessing ballistics in real life vs the abstract I’ve found.

I will kind of disagree with your conclusions regarding the GDSPs vs the GMX rounds though in regards to one being a much better performer than the other, and this goes to WS6’s point above. Given all the loads you tested easily meet the FBI’s penetration min. protocol, things like expansion, and individual performances through barriers become the primary aspects to consider.

The only all copper bonded projectile I know of that has shown to reliably defeat glass is BH’s 50gr. TSX projectile, and I believe it’s proprietary to them. This comes with it’s own downside though, because in order to address the problem with all copper projectiles sheering off peddles or collapsing upon contact with glass they had to increase the expansion threshold of the 50gr. TSX to 2300FPS from 1900FPS.

That expansion on the 64gr. and 75gr. GDSP is textbook, and I’ve never seen one not expand and hold together. The performance, reliability, accuracy, availability, and price of Fusion or Speer GDSP loads make them my number one SD round.

[ALCOAR]

@vicious_cb

Water displacement and ripping of juggs mostly captures the effect of temporary cavitation of which both DocGKR and Fackler are hesitant to apply significant wounding potential to TC. Hence I wouldnt put much stock on how much “explodiness” of water jugs correlates to terminal performance. Remember, varmint bullets are probably the most dramatic water jug exploders but there is no way I would use them as a duty load.

I’d agree for the most part, and there is no substitute for calibrated ballistic gel. However, there are several aspects that can be observed through these tests that are valuable, and informative. Bullet construction, expansion/fragmentation reliability & thresholds, and bullet track are some things that have been very helpful for myself while conducting redneck ballistic tests.

Just to illustrate your point a bit about the varmint rounds early disruption, as well as give some pictures of what jugs look like after being shot with various projectiles:

25yd/10.5" MRP CQB 5.56 testing…

Setup:

Results: (Pics below accurately depict the locations of the jugs immediately after being shot.)

MK262 Mod 1

Fragmentation was a little better than I thought it would be, but nothing special at all. The majority of upset came in second jug, and ultimately the largest fragment recovered was found in the third and final jug penetrated.

Hornady Superformance 53gr. VMAX

Fragmentation was certainly better than the MK262 considering the weight difference b/t the two especially, and while this round is a huge paper tiger in terminal ballistics…it really blows some shit up:cool: Note the location of that first jug that got A-bombed a few yards away. This round performed exactly like I thought it should…incredible disruption/upset in the first jug, and incredibly shallow penetration with only two jugs being consumed.

PRZI 55gr. SPBT

For $10.99 a box, this is pretty impressive stuff. This is another round that touches on the central theme here in this thread…“hunting” rounds deserve your consideration when picking a suitable (affordable/available/reliable/etc.) HD/PD round for your 5.56 SBR AR. This round retained 99% of it’s mass, and expanded to double it’s diameter. It had good early upset in that first jug, but that’s about all it had going for it…it had pretty shallow penetration, and was essentially done with after the second jug even though it did make it into the third.

Federal XM193F

Just like M855, the XM193 didn’t fail to disappoint. This round totally lost it’s shit in the second jug, where it turned into a wadcutter, and then dramatically tumbled upwards and to the right where it left the second jug…grazed the third, and then flew to who knows where. At least the M855 stayed put even though it didn’t fragment a smidgen, and started to tumbled heavily late into the third jug.

Clearly the two military rounds…the 5.56 M855 and XM193F massively failed.

Recovered projectiles…
(3/4 rds. tested were recovered / XM193 absent)

(L-R VMAX/SPBT/MK 262)

Penetration results…

[BufordTJustice]

@vicious_cb

Water displacement and ripping of juggs mostly captures the effect of temporary cavitation of which both DocGKR and Fackler are hesitant to apply significant wounding potential to TC. Hence I wouldnt put much stock on how much “explodiness” of water jugs correlates to terminal performance. Remember, varmint bullets are probably the most dramatic water jug exploders but there is no way I would use them as a duty load.

I already knew all of that. Hence my disclaimer in the very first post in this thread.

I’ve tested varmint rounds and they are actually vastly less spectacular than you’d think, with the amount of damage to the jugs being in much more direct proportion to their real world wounding ability (less than stellar) than you’d think.

I’ve done extensive terminal ballistic research on all of these, and hunted hogs with all but the 75gr and 55gr gold Dot. And, I’m here to tell you that there is a rough correlation with my unscientific observations and my experience hunting wild hogs.

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[BufordTJustice]

@ALCOAR

Good test brother. Well laid out, and the pics are nice. One can gain invaluable knowledge when witnessing ballistics in real life vs the abstract I’ve found.

I will kind of disagree with your conclusions regarding the GDSPs vs the GMX rounds though in regards to one being a much better performer than the other, and this goes to WS6’s point above. Given all the loads you tested easily meet the FBI’s penetration min. protocol, things like expansion, and individual performances through barriers become the primary aspects to consider.

The only all copper bonded projectile I know of that has shown to reliably defeat glass is BH’s 50gr. TSX projectile, and I believe it’s proprietary to them. This comes with it’s own downside though, because in order to address the problem with all copper projectiles sheering off peddles or collapsing upon contact with glass they had to increase the expansion threshold of the 50gr. TSX to 2300FPS from 1900FPS.

That expansion on the 64gr. and 75gr. GDSP is textbook, and I’ve never seen one not expand and hold together. The performance, reliability, accuracy, availability, and price of Fusion or Speer GDSP loads make them my number one SD round.

Gold Dot rounds of the 64gr variety have been middling performers in my hunting experience. Often requiring an additional anchoring shot even when the heart has been destroyed. I’ve not had to do that yet with the GMX rounds. Ever. Even on 250lb hogs and bigger.

And I’ve seen several Hornady GMX laminate auto glass tests where zero petals were shed. And I’ve also seen the 50gr BH load lose petals. I don’t think that invalidates either round.

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[BufordTJustice]

@WS6

Ive had 70gr gmx fail to expand. This was shot broadside (far back, yes, i was not the shooter), the bullet made a punctuate entrance, tumbled, and exited as best i can tell. Here are the pictures. Fired from a 16.1 AR. The only thing i can fathom that would cause such wounding and deviation from 90* broadside is a tumble and failure to expand. Not pictured, but the inside of the ribcage entrance looked the same as the outside. Tiny hole.

I remember the first time you documented that. There just had to be a bad batch of projectiles. Mine are first gen 70gr GMX and I’ve not yet seen a sheared petal on a recovered projectile. But you’ve been documenting your issues for a couple years now. I can’t explain it.

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[ALCOAR]

@BufordTJustice

Gold Dot rounds of the 64gr variety have been middling performers in my hunting experience. Often requiring an additional anchoring shot even when the heart has been destroyed. I’ve not had to do that yet with the GMX rounds. Ever. Even on 250lb hogs and bigger.

And I’ve seen several Hornady GMX laminate auto glass tests where zero petals were shed. And I’ve also seen the 50gr BH load lose petals. I don’t think that invalidates either round.

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It certainly doesn’t invalidate either based on such small sample sizes, however it’s very well documented that all copper bonded bullets sheer peddles in certain situations. Will one encounter one of those situations happen hunting hogs…most likely no since there isn’t any glass or sheet metal involved when hog hunting even though WS6 has posted an example of that happening.

I’ve seen a test where a 70gr. TSX and the Hornady loading 70gr. GMX fired into water @ 100yds…the TSX expanded correctly, whereas the GMX sheered off a couple peddles. When you combine all these anecdotal examples with validated testing by experts it shows all copper bullets aren’t as reliable in their wounding mechanism (sheering off pedals) as the other top barrier blind SD loads in similar testing.

Now those tests are for humans, not hogs or game…so perhaps were just crossing wires here. The GMX projectile could very well be a better hunting bullet than those others you listed. I’m just speaking in the context of PD, and the wide array of potential situations one might find themselves in.

[BufordTJustice]

@ALCOAR

It certainly doesn’t invalidate either based on such small sample sizes, however it’s very well documented that all copper bonded bullets sheer peddles in certain situations. Will one encounter one of those situations happen hunting hogs…most likely no since there isn’t any glass or sheet metal involved when hog hunting even though WS6 has posted an example of that happening.

I’ve seen a test where a 70gr. TSX and the Hornady loading 70gr. GMX fired into water @ 100yds…the TSX expanded correctly, whereas the GMX sheered off a couple peddles. When you combine all these anecdotal examples with validated testing by experts it shows all copper bullets aren’t as reliable in their wounding mechanism (sheering off pedals) as the other top barrier blind SD loads in similar testing.

Now those tests are for humans, not hogs or game…so perhaps were just crossing wires here. The GMX projectile could very well be a better hunting bullet than those others you listed. I’m just speaking in the context of PD, and the wide array of potential situations one might find themselves in.

I don’t agree with any of that.

“Very well documented”?

No, it’s not.

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[ALCOAR]

I guess we’ll have to agree to disagree. Documented means just that, tests or occurrences showing where it’s failed fwiw.

Nonetheless, I wanted to present a counter argument to your assertation that Hornady GMX loads were head and shoulders above the GDSP loads in the context of actual self defense for those that might read this thread in the future. It’s up to them to then research expert opinions on this matter like Dr. Gary Roberts to make up their own mind on this subject.

[BufordTJustice]

@ALCOAR

I guess we’ll have to agree to disagree. Documented means just that, tests or occurrences showing where it’s failed fwiw.

Nonetheless, I wanted to present a counter argument to your assertation that Hornady GMX loads were head and shoulders above the GDSP loads in the context of actual self defense for those that might read this thread in the future. It’s up to them to then research expert opinions on this matter like Dr. Gary Roberts to make up their own mind on this subject.

Still no.

I’ve been carefully studying Doc Roberts’ body of work since before his first NDIA presentation. I don’t get lectured on his work.

Further, you seem blissfully unaware that there are occurrences of literally every single modern projectile design failing to perform as intended. However, in careful consideration of our delicate casual or neophyte readers, the impression created by your statement that these occurrences are statistically relevant to the discussion are dangerously incorrect.

In clear terms of the overall percentage mass lost through auto glass, there is very little mathematical difference between homogeneous solids and bonded lead core projectiles; they both lose mass when traversing barriers such as laminate auto glass. Further, the occasional shedding of petals has not shown to have a meaningful difference in terminal effectiveness after the barrier aside from increasing penetration by an inch or two. With notable exceptions like the USMC SOST non Bonded round by federal/atk.

Lastly, you have not accurately stated my assertions. And they don’t need restating; see my original posts.

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[WS6]

@BufordTJustice

I remember the first time you documented that. There just had to be a bad batch of projectiles. Mine are first gen 70gr GMX and I’ve not yet seen a sheared petal on a recovered projectile. But you’ve been documenting your issues for a couple years now. I can’t explain it.

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This projectile was sent to me directly by Black Hills a couple of months ago. It was not defunct, defective, or otherwise an issue. It was not from the same batch my other issues stemmed from, nor have i had petal shedding from this run. Other bullets (4 from this same box) used to kill deer resulted in perfect and dramatic performance.

Now compare those entrance and exits at 23m, fired from a 14.5 to he abovee performance, at 120m or so, fired from a 16.1, especially! The punctuate and nontraumatic entrance. I feel this round failed to expand for whatever reason, and yawed (remember, it was a near perfect broadside shot, and impacted near the middle of the animal yet came out the front arm pit nearly…120m is well within its envlope from a 16.1

I dont have it pictured, but the inside of the rib cage showed a near .224 hole on the entrance side. See above, and the entrance is near nickel sized on my buck. I maintain that expansion failed.

[WS6]

@ALCOAR

It certainly doesn’t invalidate either based on such small sample sizes, however it’s very well documented that all copper bonded bullets sheer peddles in certain situations. Will one encounter one of those situations happen hunting hogs…most likely no since there isn’t any glass or sheet metal involved when hog hunting even though WS6 has posted an example of that happening.

I’ve seen a test where a 70gr. TSX and the Hornady loading 70gr. GMX fired into water @ 100yds…the TSX expanded correctly, whereas the GMX sheered off a couple peddles. When you combine all these anecdotal examples with validated testing by experts it shows all copper bullets aren’t as reliable in their wounding mechanism (sheering off pedals) as the other top barrier blind SD loads in similar testing.

Now those tests are for humans, not hogs or game…so perhaps were just crossing wires here. The GMX projectile could very well be a better hunting bullet than those others you listed. I’m just speaking in the context of PD, and the wide array of potential situations one might find themselves in.

That was my test with the GMX. Today’s 70gr GMX is not that GMX.

[WS6]

Buford, your projectiles look like oooollldddd stuff. Like, way old. The stuff i tested previous that shed petals was newer. This last batch im testing is yet the latest revision. Compare this round, fired at something like 40m from a 14.5 (impact at around 2700ish) on water jugs to yours. This is latest gen for this projectile.

[Clint]

Nice write-up!

How do you the performance hold up from a VERY short barrels?

[vicious_cb]

@BufordTJustice

I already knew all of that. Hence my disclaimer in the very first post in this thread.

I’ve tested varmint rounds and they are actually vastly less spectacular than you’d think, with the amount of damage to the jugs being in much more direct proportion to their real world wounding ability (less than stellar) than you’d think.

I’ve done extensive terminal ballistic research on all of these, and hunted hogs with all but the 75gr and 55gr gold Dot. And, I’m here to tell you that there is a rough correlation with my unscientific observations and my experience hunting wild hogs.

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I know you’re one of the more informed people on terminal ballistics and bullet selection, just throwing it out there since other people might not fully understand what you meant by the warning: “it is NOT a tissue stimulant.” A naive reader of your post may very well conclude that “more explody = deadlier bullet” which is not necessarily the case.

I do appreciate you sharing this data though my conclusions would probably differ. When I look at water jug testing I mainly look at the end state of the bullet ie. how much it expanded and how many jugs it penetrated. Ive noticed higher velocity or “hotter” loads tend to produce more dramatic effects in water which is counter to the fact that velocity is NOT a wounding mechanism.

Recently after sifting through more of the academic journals from Fackler et al. and listening to some of the more recent DocGKR stuff Im starting to devalue temporary cavity more and more. Funny, the deeper down the rabbit hole of terminal ballistics I go, the more I realize you just poking a hole and all the arguments about TSX vs GMX vs Gold Dot matters very little reality and this is all just a fun and educational exercise in minutiae.

[WS6]

@vicious_cb

I know you’re one of the more informed people on terminal ballistics and bullet selection, just throwing it out there since other people might not fully understand what you meant by the warning: “it is NOT a tissue stimulant.” A naive reader of your post may very well conclude that “more explody = deadlier bullet” which is not necessarily the case.

I do appreciate you sharing this data though my conclusions would probably differ. When I look at water jug testing I mainly look at the end state of the bullet ie. how much it expanded and how many jugs it penetrated. Ive noticed higher velocity or “hotter” loads tend to produce more dramatic effects in water which is counter to the fact that velocity is NOT a wounding mechanism.

Recently after sifting through more of the academic journals from Fackler et al. and listening to some of the more recent DocGKR stuff Im starting to devalue temporary cavity more and more. Funny, the deeper down the rabbit hole of terminal ballistics I go, the more I realize you just poking a hole and all the arguments about TSX vs GMX vs Gold Dot matters very little reality and this is all just a fun and educational exercise in minutiae.

Velocity IS a wounding mechanism at 1800+. It contributes greatly to secondary projectiles as well. As a matter of fact, this doe (shot with 70gr gmx by me at 78m) had secondary projectiles all through the top 3" of her lungs from her spinal column. Further, expanded bullet shape, etc. Does matter. A large flat meplat will destroy tissue more than a rounded one. Especially at the latter portion of the wound tract. My ra556b at 27m (pix on harddrive, not phone) produced significantly less damage than my 70gr gmx at 23m, from a shorter (14.5 vs 16.1) barrel on the exit side. Very interesting about bullet shape, weight, etc… the wounds look like they cam from different caliber weapons, and you can see the value of retaining velocity through the target. Lots of blood trail on the 70gmx, none really on ra556b.