75gr Hornady BTHP
23.7gr Varget
LC brass
CCI 400
2.26 COL
Bushmaster 24" stainless 1:8
2727fps avg. = .75 MOA at 200yds

77gr SMK
24.1gr Reloder 15
R-P brass
S&B SRP
2.260 COL
2473 fps out of a 16" stainless Aeroprecision barrel
Shoots sub moa at 200, will shoot half inch at 100 if I do my part.

75 gr Hornady BTHP
23.5 gr Benchmark
CCI 400 Primers
LC Brass
2.252" COL

Shoots 3 shot cloverleafs out of my 16" Green Mountain fluted 1:7 twist chrome lined barrel and my cousin's 16" Palmetto State HBAR 1:7 twist CHF barrel.at 100 yards, and confirmed sub-MOA at 300 with both guns as well.

27.0 grains of Benchmark
40 grain Nosler tipped varmagedon
Winchester brass
CCI 400 primers
2.250" OAL

I was getting crazy good 5 shot groups at 100 meters at my indoor range through my 24" .223 Wylde AR Stoner barrel.

5 shots under 3/4" with 3 shots under 3/8".

Very consistent results for the 50 rounds I had loaded.

Ordered 500 more of those bullets when I got home

69 grain Sierra Match King
OACL 2.260
CCI #41 primer
New LC brass
23.5 grains of TAC

Saw this really show some promise during load development.  Over the course of 18 rounds fired over 30 minutes of 6 different charge weights, three non-consecutive rounds grouped under 1/2" at 100 yards.

Rifle is a franken-gun with LaRue 16" barrel, SAA bolt and carrier, SAA upper receiver.

50 grain vmax tipped bt - like a-max but way cheaper!  
22.7 grains of LT-32
rem 6 1/2 primer

shot a 2" group at 400 yards from my ruger M77 MkII all weather in 1:12 twist.  then centerpunched all 5 swinging gongs.  

didn't chrono it but should be right around 3250 - 3300 based on comeup.

77 Nosler CC
23.2 IMR 8208xbr
Wolf SRM
LC 09 1x
2.245"

2664 avg from a 14.5" Larue stealth
SD 16

has shot sub moa out of 3 guns thus far

Running a 52 grain Flat Base Berger with that powder.

26.0 grains of 4895
Federal GM205MAR
Lapua cases
2.260" COAL

New American Eagle LC stamped 5.56mm brass
CCI #41 primers
69 grain SMK
2.250 OACL
23.2 grains of Ramshot TAC powder

Getting sub 1" at 100 yards with 4 AR 15 style rifles so far (2xFrankenguns, 1x KAC SR15, 1xRainer Arms AA Piston upper)

Sub 2" at 200 yards out of my LaRue Stealth Barreled Frakengun...

With  Sierra 77 TMK bullets being so long, and with a secant ogive, is it worth switching out Pmags for ASC stainless steel mags with long inside COAL measurements (2.316 vs 2.26) in order to load them a bit longer than standard mag length?

I have used them from mag length to 2.32 and not had problems with seating depth and accuracy, If you were wanting to try and get a little more powder in them, it might help some. I am probably going to get some of the ASC mags to try out eventually.

Just loaded up and shot some test loads and I'm stumped over the results.

Once shot SSA 5.56 brass, full length resized, trimmed to 1.750"
77 TMK, 22.6 gr 8208 xbr, seated to 2.255", compressed load
Rifle has a 18" Lothar Walther .223 Wylde barrel
Velocities measured with Magnetospeed v3

Groups were good, under MOA. SD and ES were pretty good too. But velocity was really low, averaging 2580 fps, which is about 100 fps less than what others are reporting with this same load in 5.56 brass. I checked my chronograph against factory ammo and it's spot on.

Also, getting occasional split case necks from twice fired SSA. No pressure signs. Brass was tumble cleaned and inside of necks were scrubbed with nylon brush.

Could this brass be thin enough to cause less capacity and lower velocities? I think Norma makes it for Silver State Armory, they sell for $.44/100, which is pretty cheap new 5.56 brass, and SSA 5.56 77 gr OTM are some of the cheapest factory "match" ammo, so they have to be cutting corners somewhere.

Any ideas?

I typically don't see necks split until the 6th or 7th cycle.  If you're seeing it begin on the 2nd, that batch unfortunately won't last long.  
Not to get side-tracked, but start researching DIY annealing.  It's not hard to do, and can tripple the life of your brass.

As far as the velocities go, I'd say you're right where you should be.
FWIW, I've found the semi-auto/gas gun 77 grain 'sweet spot' to be 2550-2600fps
I've tried pushing them harder, and accuracy degrades (and beats the snot out of the brass).

Norma is outstanding quality brass, among the best available... I didn't know they made SSA's brass.  
They may have different quality standards for SSA vs their own branding however.  Just thinking out loud; I honestly don't know.
Whatever the reason, they should not be splitting necks so soon.

For my 77 TMK load dev. experiments I tried it again, this time with LC brass, and upped the powder loads, worked out great! Under MOA and velocities were nice. No split case necks. Best of all, rounds fit in all mags, including Pmags. So much for being jump sensitive.

77 TMK
23.2 gr IMR 8208 XBR
LC Brass (1.750")
CCI BR-4
2.255" OAL
2634 fps, SD 8.5, ES 22


I also tested out a 75 BTHP load, which shot even better than the 77 TMKs at 100 yards:

Hornady 75 BTHP
23.2 gr IMR 8208 XBR
LC Brass (1.750")
CCI BR-4
2.255" OAL
2696 fps, SD 5, ES 14

68gr Hornady match BTHP out of a 20" bull barrel, 223 Wylde, 1:8 twist
23.4 gr H4895
Remington Brass
CCI 400
2.250 COAL, 1.835 to Ogive
No speeds as I don't have a chrono yet, but shooting just over .75 MOA at 200yds.

That is exactly the recipe I use (w/Nosler 77gr CC cannelured)  with excellent results. This load shoots at or below 1 MOA out of my two 1/8 twist POF P415s and my 1/7 twist Colt LE6920 at 100 yards. I just started loading 77gr bullets recently, and haven't had the chance yet to try them past 100 yards, but initial testing has been very good.

I did use a Lee FCD to apply a light crimp at the cannelure. I do this with all of my .223 loads when a cannelured bullet is used. Just a little extra insurance against the possibility of bullet setback.

77gr SMK moly
23.8gr H4895
CCI 400
2.250"

20" Wylde 1:8.

Average: 2814fps (I think the chrono read a little high)
ES: 36fps
SD: 11fps

-----------------------------ETA 25-Sept-17--------------------------------
Avg - 2795fps
ES - 74fps
SD - 24fps

~2800fps is stout from a 20" barrel. CCI 450 primers recommended.
-------------------------------------------------------------------------------

Shoots well enough in 3 RRA and 3 DPMS National Match rifles. From my RRA last July 4th:

Attached File

73gr Hornady ELD Match
21.1gr AR-Comp
WCC Brass
Federal Match Primer
2.255" COL
Shoots .6 MOA

82gr Berger
23.4gr Varget
CCI 450
Small letter FC case
2.450". About 0.010" off lands in CLE chamber(?)

Load test:
Attached File

No-wind match:

Here are a few of mine out of my 18" Larue.  

53gr VMax
H322
2.250"
When I did my load workup (22.5-23.5gr), the three middle loads (22.7, 23.0 & 23.2) all shot between in the .75-.80" range.  It's got a wide accuracy node, so it's incredibly tolerant of case choice, powder variations, temperature and primer choices.  

Below is 23.0gr H322, Federal 205 Primer, Winchester Brass:

image 

Similarly, a variation of AeroE's load is showing promise.  27.0gr RL15, Federal 205 Primer, Winchester Brass:

image 

For heavies:

77gr Nosler/77gr SMK
21.6gr H322
Winchester brass
CCI BR4 or Federal 205 primers
COAL 2.250"

Top is CCI BR4, bottom is Federal 205 Primers.  

image 

image 

Another short range load.

50gr VMAX
21.0gr H4198
CCI 450
Small letter FC case
2.255"

Load density is about like an M1 Garand load. That or lighting seemed to affect the chronography.

From a 16" 1:7 carbine.
Avg: 2850fps
ES: 150
SD: 50

Load test.
Attached File


Then I finished up today's match with this.
Attached File

My experience with H4198 has been the same. Very high extreme spreads and standard deviations, very small groups on target.

I use 20.6 grains of H4198 with 52/53 grain Sierra Match Kings seated at 2.240".

5/8" groups at 100 yards are common. This combination hammers at 100 yards, works reliably in carbine and mid-gassed rifles. Usually functions 100% in 20" rifle gassed rifles.

I only tried 10 shots through the 20" and it felt about the same as the carbine - seeming to barely hit the back of the receiver extension. It's old and slick though.

Does anyone know what is the recommended barrel twist for the Hornady 88 ELD. they don't have it on their website

It's about the same length as a Berger 90 BT and 0.070" longer than Sierra's 90.

Berger's twist calculator says 1:6.5 is perfect at SG 1.5. A 1:7 is marginal at SG 1.3.

Colt 6721:  5.56 NATO CHAMBER "16 inch barrel" with a 1:9 twist and a Midwest Industries FF hand-guard/Geissele trigger combo

Sierra #1390 55gr HPBT
26.1gr H4895
CCI #41's  (If you use another primer type your velocity WILL be lower)
2.240 ( if you have a Wylde chamber you may be driving this length into the lands. You have to know your distance to the lands with this one!!!)
LC 2011 Nato brass
Shoots .6 MOA all day rarely better and rarely worse. 200 yard amazingness.
2965fps - 3005fps day in, and day out, season in, season out. (average 2980-3005fps most days)
This is not a one day at the range wonder.

This turns off a Coyote like a light switch.

******

Colt 6724: 5.56 NATO CHAMBER "24 inch barrel" with a 1:9 twist. OEM free float factory rifle with a Geissele SSE trigger SSA-E trigger.

Nosler 55gr Ballistic Tip.
26.7gr W748 (cool weather load)
WSR primers
Federal Premium Brass
2.250
Shoots .4-.6 inch groups through the years
3100fps
This load is not a one trip to the range wonder. It is the most accurate day in and day out. Good day, bad day load i have ever used.

This load and bullet combo will make your friends call you a liar.
*****

Saber Defense upper with an old school FN CHF "20 inch barrel" 5.56 NATO CHAMBER with no M4 feed ramps. Geissele 15 inch rail and a Geissele NM trigger.

Sierra 77gr BTHP
23.4 gr IMR XBR 8208 (Real soft shooting, no pressure)
CCI #41 primers
LC NATO brass 2013
2.250 average (can vary 10 thousandths each way, and does.)
Shoots .9 MOA through 300 yards with regular and repeatable consistency. Just fantastic for gov profiled military barrel.
2675fps.

*****

This is my come and take it rifle.

Or come and try to take it anyway.

All of these loads can handle at least 4 reloads after the factory firing of M855

I always spend up for new Federal Premium brass. I normally shoot those 5 times before i turn it into a plinker case that goes in the garbage.

Sierra 77gr BTHP
23.4 gr IMR XBR 8208 (Real soft shooting, no pressure)
CCI #41 primers
LC NATO brass 2013
2.250 average (can vary 10 thousandths each way, and does.)
Shoots .9 MOA through 300 yards with regular and repeatable consistency. Just fantastic for gov profiled military barrel.
2675fps.

Using same load data with 77 grain CC and getting similar results.  I have read where reloaders call this recipie the  “easy button” for 75-77 grain bullets and I believe it.

LC 17 brass
Fed AR match primer
2.255 OAL

69gr smk
25.0-25.2 RL15
25.0-25.5 CFE223

77gr smk
23.3 RL15

Will post pics later

I have been shooting this one a lot lately from 100-800 yards from a WOA 3 gun 2.5 BBL with good results. Hits MOA sized targets to 500 with relative ease and a 2/3 IPSC at 800 if the wind isn’t terrible. It’s completely out of gas after that though and won’t hit anything consistently beyond 800.

LC brass trimmed to SAAMI
Winchester SRP
23.6 8208 XBR
2.255 COAL
Hornady 73Gr ELDM.

The 8208 meters fantastic too so I don’t have to weigh every charge and makes it fun to load as well. I don’t mind weighing individual charges for my bolt guns if I’m going for super small groups but if I’m just trying to bang MOA steel, I like a powder that meters well enough that I don’t have to worry about it.