Terminal effects of common 5.56 duty loads from a 10.5" barrel?

[Galbraith]

I'm trying to get reliable information regarding the terminal effects of 5.56 duty loads(particular Speer 62gr Gold Dots) fired from a 10.5" barrel. This will be for multiple LE guns which need to be effective out to 200yrds, and my concern is that the barrels will not be optimal for these duty requirements. Any links to papers/research would be extremely appreciated.

[andre3k]

I'm interested in seeing the responses as well. One of the officers in my squad used the 55gr GD load in a shooting last night.

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[Darth_Uno]

https://www.recoilweb.com/sbr-ammo-buyers-guide-141394.html

Not a big fan of Recoil but tests are tests.




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[the Schwartz]

https://www.recoilweb.com/sbr-ammo-buyers-guide-141394.html

Not a big fan of Recoil but tests are tests.

I'd respectfully beg to differ.

The author's commentary throughout the article suggests that 1.) he knows very little about the composition of the Clear Ballistics stuff (there's no silicon in it) that he is using to "test" the ammunition and 2.) that his understanding of the scientific method is more than a little lacking in that if one makes the direct observation that the test medium is an inaccurate one that proceeding with testing is likely to yield nothing but inapplicable results.

In other words, garbage in (conducting tests with an unproven, uncorrelated medium); garbage out (obtain test data that applies only to the unproven, uncorrelated test medium). Ultimately, the test data obtained does not, and cannot, be used to predict the terminal performance of the ammunition being tested in anything other than the Clear Ballistics stuff.

Mr. Curtis' article, at best, is a well-documented example of wasting time, energy, and money to obtain worthless test results and data.

[Nightvisionary]

The Federal LE website states it will expand out to 200 yards with 10 inch barrels. My own tests on ClearBalistics gel with a 10.5 using 62 and 64 grain Gold Dot exhibited excellent expansion to about .50.

https://le.vistaoutdoor.com/ammunition/speer/rifle/default.aspx

[Clusterfrack]

Anyone have any data on the 75gr TAP SBR load?

[the Schwartz]

Anyone have any data on the 75gr TAP SBR load?

Here you go:

http://www.hornadyle.com/products/rifle-ammunition/223-remington/75-gr-bthp-tap

Just hit the "Gelatins" tab near the bottom of the page.

41205

[HCM]

Thread on the 75 grain TAP SBR

https://pistol-forum.com/showthread.php?17339-So-I-got-to-shoot-Hornady-s-new-5-56-Nato-75-Grain-TAP-SBR-load-yesterday

You’ll also want to read Doc GKR’s stickies threads

https://pistol-forum.com/showthread.php?4344-5-56-mm-Duty-Loads

https://pistol-forum.com/showthread.php?4343-5-56-mm-55-gr-M193-Terminal-Performance-Thoughts

Mechanical advantages aside, another reason to go with 11.5” barrels is thy are the new standard for federal LE Agencies (FBI, ICE, USBP, USSS etc) which opens up a lot more data.

Bonded 62 grain softpoints from federal and Winchester and 62/64 grain gold dots are pretty much universal.

[Jay Cunningham]

I'm trying to get reliable information regarding the terminal effects of 5.56 duty loads(particular Speer 62gr Gold Dots) fired from a 10.5" barrel. This will be for multiple LE guns which need to be effective out to 200yrds, and my concern is that the barrels will not be optimal for these duty requirements. Any links to papers/research would be extremely appreciated.

200 yards ain’t gonna cut it. Maybe 65/70 yards.

But you may want to reconsider what you mean as “effective” on a 200 yard threat.

[HCM]

I'm trying to get reliable information regarding the terminal effects of 5.56 duty loads(particular Speer 62gr Gold Dots) fired from a 10.5" barrel. This will be for multiple LE guns which need to be effective out to 200yrds, and my concern is that the barrels will not be optimal for these duty requirements. Any links to papers/research would be extremely appreciated.

How far out do y’all qualify ?

We do 100 yards though we often have to simulate that stage with a half sized target. It seems most agencies only qual out to 50 yards.

Are y’all running optics ? If so what optics ? RDS ? I ask because it is a lot easier to hit things at 200 than positively ID targets at 200 and positive ID is mandatory in CONUS LE work.

[DocGKR]

For most LE shooters using AR15 SBR's with an RDS and typical ammo they are going to be 100 yd guns. Add a 1-6x or 1-8x LPV and good ammo, then we are talking up to maybe 200-300 yds for most shooters given some decent training and ongoing practice.

[WDR]

200 yards ain’t gonna cut it. Maybe 65/70 yards.

But you may want to reconsider what you mean as “effective” on a 200 yard threat.

With ball ammo (M193/M855 equivalents) in a 10.5"... yeah, you wont get much fragmentation (effectiveness) past 70 yards. With some of the modern bonded soft points, you should see at least some expansion out to close to 200 yards. Of course, the expansion you do get at 200 wont be the same as what you'd see at 50 or even 100 with the same load/gun. I think I'd feel confident about shots inside 100 showing decent expansion if you pick your ammo carefully. 200 really is probably a stretch with these short guns, ammo performance wise.

My understanding is that the Fusion MSR load is loaded a bit hotter than the standard Fusion stuff, and also a bit hotter than Speer Gold Dot... all of these in 62gr weight. The little bump in velocity should increase the range where you'd see bullets expanding. I believe bullet construction is the same or at least very similar between the Fusion and Gold Dot lines. Worth checking into.

The Fusion/Gold Dot loads have been pretty effective on game for me, though those shots were fired from 16-20" guns.

I also spent the time to find an 11.5" barrel when I started looking into short guns... the bump in velocity isn't huge, but dwell time and reliability both go up, from what I have read.

[Tokarev]

Been awhile since we used 64 Gold Dot. We've since switched to 62 Federal ETSP.

Anyway, from what I can remember, the Gold Dot stuff chrono'ed around 2,650 from a 14.5" and around 2,550 from an 11.5.

Going off beer saturated memories so please don't hold me to these numbers...



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[Tokarev]

the Gold Dot stuff chrono'ed around 2,650 from a 14.5" and around 2,550 from an 11.5.


Using my velocity of 2,550 fps as posted above we can guesstimate the Gold Dot to expand out to about 250 yards. Not to say that it couldn't or wouldn't be effective beyond that. That's also assuming it will reliably expand at 1,700 fps.


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[Rockey]

Using my velocity of 2,550 fps as posted above we can guesstimate the Gold Dot to expand out to about 250 yards. Not to say that it couldn't or wouldn't be effective beyond that. That's also assuming it will reliably expand at 1,700 fps.

Per Speer the expansion threshold is 1800 fps and some testing that I have seen more like 1900-2000 fps.

[Tokarev]

Per Speer the expansion threshold is 1800 fps and some testing that I have seen more like 1900-2000 fps.200 yards then.

Still probably pretty respectable performance for a general issue LE carbine or AR pistol.

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[Default.mp3]

Anyway, from what I can remember, the Gold Dot stuff chrono'ed around 2,650 from a 14.5" and around 2,550 from an 11.5.FWIW, the 62 gr. was 2759 FPS out of my Centurion Arms 14.5" with a SureFire SOCOM556-RC, and 2536 FPS out of my Centurion Arms 11.5" with a SureFire SOCOM556-RC2, measured with my MagnetoSpeed. 75 gr. Gold Dot was 2611 FPS and 2471 FPS respectively. Federal Fusion MSR was 2825 FPS out of the 14.5" suppressed, no data for the 11.5".

[Rockey]

200 yards then.

Still probably pretty respectable performance for a general issue LE carbine or AR pistol.

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True, but that data is from an 11.5" barrel.

OP was asking about 10.5", and there is a considerable performance difference in that one inch.

Realistically, it is probably a 150 yard load.

[Tokarev]

OP was asking about 10.5", and there is a considerable performance difference in that one inch.

What is the MV from a 10.5?

Here is a bit of penetration and expansion data:

http://www.activeresponsetraining.net/ar-15-pistol-ballistic-gel-testing


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[HCM]

True, but that data is from an 11.5" barrel.

OP was asking about 10.5", and there is a considerable performance difference in that one inch.

Realistically, it is probably a 150 yard load.

Hence why everyone is trying to convince him not to go with anything shorter than an 11.5”

[Galbraith]

Thanks for your help on this matter guys. I presented a write up of the concerns to the chief in a meeting, so we'll see what happens. I will simply state that certain upper brass have a habit of choosing what they want regardless of educated, experienced, input that contradicts what has already been set in motion. :rolleyes: