Wow, I just now ventured into this thread, and it is epic. Tons of fantastic information, so thanks Molon for that! Are you still planning on releasing an updated .pdf version? Also, it's mentioned a few times that AD military can order the 5.56 TAP from Hornady but can any individual AD personnel place an order or is it "my command would like to order 10,000 cases" sort of thing?

I'm probably just being paranoid, but I just bought a couple hundred rounds of the 5.56 75gr TAP (#8126N) from an individual and I want to be sure that this is factory ammo and not reloaded/reman. I ask because in most of the pictures that I've seen (including those in this thread), the brass looks a lot cleaner than mine. I'm pretty new to the 5.56 cartridge in general so I wanted to make sure. See pictures below.

http://picklematrix.org/guns/tap556-0009.jpg

http://picklematrix.org/guns/tap556-0011.jpg

Apologies if this is much ado about nothing!

Seems to be new ammo.

Okay, thanks for the reassurance. I don't have any reason to be suspicious of the seller, just wanted to confirm.

Thanks Mo'

man the LEO is lots faster than the FPD .

There is now a fifth, 5.56mm heavy OTM match round on the commercial market that is loaded to mil-spec velocities.  The new load is from a company called Buffalo Bore and it is loaded with the 77 grain Sierra MatchKing.  





The ammunition is loaded in Winchester commercial brass and does not have sealed or crimped-in primers.  The 77 grain MatchKing used in this load does not have a cannelure, but there is a very slight taper crimp at the case mouth.  There is no neck sealant used.  The round is charged with a flattened “ball” powder.




I chronographed this load from a 20” Colt barrel with a NATO chamber, chrome lining and a 1:7” twist.  The muzzle velocity was 2853 FPS with a standard deviation of 20 PFS.

COR-BON’s website advertises that this load has a velocity of 2800 FPS from a 20” barrel.  I’m here to say “it just ain’t so.”  From the 20” Colt barrel it did have a respectable muzzle velocity of 2674 FPS with a standard deviation of 19 FPS.  

I still dont understand how they can claim to SAAMI .223 spec pressures and have velocity slightly faster than Mk262. Did they invent some magical powder or something?

its because they used that crappy lapua brass if you have any i will take it off your hands

Cor-Bon has a history of exaggerated velocity claims.

Years ago, my Dad bought into the hype and bought some handgun rounds.
Velocity was all over the place, one round a very satisfying "BOOM", next round "pop", almost squib like, another round somewhere between the two.
That was the last time he bought Cor-Bon.

Somehow, I'm not suprised.  I wonder what powder that Buffalo Bore load is using though, I'd like to load some 77gr SMKs soon since TAP is expensive and extremely difficult to obtain.

I was talking about buffalo bore ammo

oooopps guess i'll re reead,i flunked evelyn woodhead spaed raeding cuorse

Nosler 77 grain BTHP



In 2003, Nosler introduced their 77 grain Custom Competition BTHP bullet as an obvious competitor to the 77 grain Sierra MatchKing.  The shape and ballistic coefficient of the Nosler bullet is very similar to that of the Sierra MatchKing.  The Nosler bullet does have one major difference from the Sierra MatchKing; it is constructed using the thinner J4 copper jacket.

I recall an early Nosler advertisement for their Custom Competition bullet  that included a phrase saying the bullet was “ideal for military and law enforcement,” hinting at the possibilities of improved fragmentation due to the thinner J4 jacket.  Thanks to the works of Dr. G.K. Roberts and B&T Ammo Labs, we know that the 77 grain Nosler bullet loaded to mil-spec velocities has superior terminal ballistic properties to that of the 77 grain Sierra MatchKing loaded in MK262.  The terminal ballistic properties of the 77 grain Nosler bullet loaded to mil-spec velocities rival that of the Hornady 75 grain 5.56 TAP load.  Unfortunately, there are no ammunition manufacturers currently loading the 77 grain Nosler to mil-spec velocities.


Courtesy of Dr. G.K. Roberts



Courtesy of B&T Ammo Labs


The Nosler 77 grain Custom Competion bullet is typically sold without a cannelure, however Nosler occasionally releases the bullet with a shallow cannelure similar to the one found on the 77 grain SMK loaded in MK262.  The cannelured version of the 77 grain Nosler will be the focus of this report.












For the first phase of testing, I hand-loaded the cannelured version of the 77 grain Nosler BTHP to a typical SAAMI velocity (approximately 2600 fps from a 20” Colt barrel) to establish an accuracy baseline.  No case mouth crimp was applied at this phase.  As per my usual protocol, accuracy testing was conducted from a concrete benchrest at a distance of 100 yards.  The forend of my Krieger barreled AR-15 rested in a Sinclair Windage Benchrest, while the stock of the rifle rode in a Protektor bunny-ear rear bag.  A Leupold Competition Scope was used for sighting.  Wind conditions were monitored using a Wind Probe.  





Three 10-shot groups were obtained which had extreme spreads of:

0.797”
0.827”
0.812”

for a 10-shot group average of 0.812”.  The three groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group.  The composite group had a mean radius of 0.26”.  This test shows that the Nosler bullet itself is capable of consistent sub-MOA accuracy at 100 yards when fired from a semi-automatic AR-15.







For the second phase of testing, I safely worked up a load for the 77 grain Nosler BTHP to a nominal muzzle velocity of 2800 fps from a 20” barrel using a non-canister grade military powder which has a velocity-to-powder-charge ratio that is very close to that of the powder used in MK262. (In previous testing, I found that the average muzzle velocity from seven different lots of Hornady 5.56 TAP was 2808 fps from a 20” barrel.)  No case mouth crimp was used in this phase of testing either.

Since my Krieger barreled AR-15 has a 5.56mm Match chamber that is “a little too tight” for mil-spec pressure loads, I used my AR-15 with a 20” Noveske DCM barrel for this phase of testing.  This Noveske barrel has the “Noveske Match Mod 0 chamber which is designed to offer 100% reliability while retaining maximum possible accuracy. The chamber body is slightly larger than the 5.56mm NATO minimum, but within the 5.56 NATO tolerance. The throat is redesigned for proper bullet alignment with the axis of the bore. This chamber was developed to fire MK262 Mod 1 on AUTO in hot environments."



Accuracy testing using the Noveske barreled AR-15 and Nosler 77 grain BTHP at a muzzle velocity of 2800 fps was conducted in the same manner as described above in the first phase of testing.  Three 10-shot groups were obtained from 100 yards.  Those groups had extreme spreads of:

0.880”
0.857”
0.845”

for a 10-shot group average of 0.860”.  These groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group which had a mean radius of 0.29”.







For the final phase of testing I added a taper crimp to the case mouth of the previously described load used in phase two.  A 10-shot string of this load fired over the Oehler 35-P chronograph from my 20” Novekse barrel had a muzzle velocity of 2801 fps with a standard deviation of 12 fps.

Three 10-shot groups fired from 100 yards from the 20” Noveske DCM barrel had extreme spreads of:

1.033”
0.914”
1.241”

for a 10-shot group average of 1.063”.  As before, the three groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group.  The mean radius for the composite group was 0.31”.  

Previous accuracy testing of the 75 grain Hornady 5.56 TAP load from my 16” Noveske barreled AR-15 produced a 10-shot group average of 1.22” at a distance of 100 yards with a 30-shot composite group mean radius of 0.37”.  

As previously mentioned the 77 grain Nosler BTHP has terminal ballistic properties on par with the TAP load.  This testing shows that the 77grain Nosler BTHP bullet loaded to a muzzle velocity of 2800 fps, is capable of accuracy that is slightly better than that of the TAP load.

Excellent post, I've been debating which bullet to use when I attemp to handload my own Mk 262/TAP rounds. At first I was leaning towards the regular 75gr Hornady OTM because it has a better BC than the Sierra 77gr, but after seeing this I think I'll go with the Noslers.

Molon can you provide any more info on the powder used to obtain the NATO-spec velocities?  Is this a commercially-available component?

Wow, the taper crimp opened the groups up that much?

Also

While you're looking at alternative 77gr projectiles Id take a look at the new Lapua 77gr scenar. Pretty impressive with a BC of .402 AND is loaded to magazine length.

Negative.

And "The List" gets longer.

this thread needs to be tacked stuck permanently adhered whatever top of the page.

I'll second that.

Very Impressive fragmentation;  AND, been around since 2003.  Wonder why these aren't used instead of , or at least in addition to SMK's for the boys that are currently serving ??

Excellent as usual Molon.  Thank You.

Thanks for the Nosler review.



I'd love to get my hands on a bunch of those Lapua Scenar bullets......

Must get some Scenar/Nosler loads to compete against my 5.56 red box TAP!

I wonder if those will frag well?  I like Lapua bullets (I use 155gr Scenars in .308) but am under the impression that they use very hard, thick jackets.

.....

Thanks for the pics....Same ones I got Molon. My concern is the last batch I got had visible neck and primer sealant while these LCs have none. Could the sealant be translucent or they're simply not sealing any longer? Is there a way to test? I've thought about Boiling  in water then disassemble looking for dry powder?

We shall see!

More TAP porn.

So, could it be said that the QC 'issues' as posted on pages 28-30 are largely resolved? I mean I wouldnt call unpolished brass an issue but it might be an indicator of how some corners are being cut in the manufacturing process resulting in the other defects that have cropped up lately in the last few lots which coincidentally use the WCC brass.

I don't recall there actually being defects unless aesthetics count as a defect.  IIRC, there were no performance differences for those "ugly" lots of TAP, Molon knows though and will certainly correct me if I'm wrong but your comment could possibly get everyone worked up over nothing again.  

Most recent delivery of TAP 5.56 came in with LC Brass, NATO cross stamp, and polished cases...

Same here. Can't wait to bench-test this stuff then go whack a big old doe with it to check terminal performance.

Finally got my hands on some.   UPS guy brought it about an hour ago.





I might have to fondle it a week or two before I actually shoot it.

I just checked and it's still in stock.


I wish they'd run out for a couple of months - I couldn't take it - I had to order 200 more rounds.

WW

Damn, talk about some IMMEDIATE expansion, there's almost no neck in that pic!

Does anyone know the bc for this round?
Based on Hornandy's website, it should be around 2660 fps out of a 16" barrel.

.352, as per the first page of this thread.

Has an updated PDF been made of this thread?

In progress . . .

FYI, Hornady's 22cal 75gr. BTHP Match bullet WITH CANNELURE (what you guys have termed T1C) is available in bulk from patsreloading.com. I just picked some up in person, great price to boot.

OST

Still cant find any...at a reasonable price!

Update?