Anyone have a go-to load for 77 SMK and H4895?

[BCP]

I've been trying this combination and haven't had much luck so far. The two loads I was suggested are 23 and 23.5 grains, neither of which groups very well, and I tried 2.24" and 2.26" COAL without much change. Does this powder have very small windows of accuracy? Say, 23.2-23.3? And has anyone had luck going higher than 23.5? Primers are starting to get flat but still no ejector swipe.

 

[SporterII]

No replies so -
I use it for the 69's. 3000fps. in a 23" 9 twist. Shoot tight, Easy on brass, and can reach out when conditions support.
Bolt gun I presume

http://accurateshooter.net/Downloads/sierra223rembolt.pdf

 

[2ndPanzer]

I shoot that load. 23.5 H4895, wolf SRM primers LC cases. Load to 2.255OAL

Probably the most accurate load I have ever used. In bolt gun or AR.
What rifle, What chamber and barrel are you using, and primers. I might can help. I use H4895 ALOT in the 223.

 

[2ndPanzer]

Oh and yes, I have gone to 24.0 with 77's. it's a brass killer, but also accurate.

 

[BCP]

I have lake city and remington brass and CCI/Winchester primers. I have another load workup going here from 22.4-22.6 and 23.1-23.3 @ 2.245" but haven't been able to get to the range yet. Also have 2000MR and IMR 4320 powder but I was really hoping to get H4895 to work.

 

[Scooter64]

I bought 1k 77 seconds from powder valley and i have been trying to get it to shoot in my krieger barreled ar and it worked up from 22.5 to 23.5 H4895 in .3 grain increments my records show itseems to shoot best @23.4 with 2.250 coal . Best it has shot was between .9 and .8 inch 5 round groups for me. If anything below 23.4 seems to shoot 1.2 in grps with my rifle. I am only using this powder because i have been shooting my garand and m1a alot few pounds left. In the past when powder was easier to find my powder would be varget or rl15 in ars. i only have shot one load with the 77 w rl15 with 22.5 grns that also shot between .8 and .9.

normally my rifle shoots .65 moa and sometimes better with 69 sierra or nosler cc and varget or rl 15

it could be me , the 77 grain seconds and or my current my scope, a leupold mk 6 1-6x tmr. the reticle is to busy for precise aiming for my taste and not enough magnification.

 

[2ndPanzer]

25.3-26.3 MR2000 works too. With any powder, Use mag primers. Seat to 2.255. In my bolt gun with same CLE chamber as my AR, 23.5 H4895 is rediculous.

 

[leid]

OP,
The 77gr. SMK over 5.56MM pressure H4895 shoots just as accurately as the 77gr. SMK over 5.56MM pressure TAC loading I normally use (0.5-0.6"@100yds in good conditions). The H4895 load is a little slower in warmer OATs though. But when I ran a quick check on both loads at -10F & +135F fired from an 18" 1x7.7 Krieger gas gun barrel, the H4895 load tested to be nearly immune to normal thermal variation I might see while hunting/shooting during the year. MVs are (5) shot averages loaded in virgin LC brass, #41 primer, seated to 2.255" COAL. I ran these tests twice to confirm numbers on all but the 77gr. SMK over max listed NATO pressure AA2520 load. Safety dictates that I not shoot that load at over 100 degrees or in a hot barrel ever again. Both the first & second set of numbers were very close so I feel confident with what is posted below.

Edit: I added a good bit more thermal stability test info: I am becoming of the opinion that H4895 powder may well be to the 5.56MM what Varget powder is to the 308 Win. I will definitely test H4895 powder further with the 77gr. SMK & the 70gr. Barnes TSX bullet as well.

77gr. SMK over NATO pressure Varget: (Virtually immune to thermal variation of 145 degree F. But MV is a bit slow as compared to H4895 much less
the TAC & AA2520 double based spherical powder loads)
+135: MV 2685
-10F: MV 2684
__________________
1 FPS over 145 degrees F


77gr. SMK over NATO pressure H4895: (Pretty decent MV for a single based stick rifle powder especially when used in colder temperatures)
+135F: MV 2741
-10F: MV 2737
_________________
4 FPS over 145 degrees F


77gr. SMK over 5.56MM Hodgdon EXTREME powder: (This is factory SOUTHWEST Ammunition 77gr. SMK RUN-N-GUN load: VERY NICE Zach et al!)
+135F: MV 2746
-10F: MV 2728
__________________
18 FPS over 145 degrees F


77gr. SMK over max listed NATO pressure TAC:
+135F: MV 2841 FPS
-10F: MV 2723 FPS
_________________
118 FPS over 145 degrees F


Factory Black Hills 77gr. SMK based MK 262 MOD 1: (This lot was produced after the non-canister spherical powder used in MK 262 MOD 1 cartridges was further thermally stabilized around 2005 to help mitigate possible overpressure when required to fire in overheated M4/M4A1 carbines.)
+135F: MV 2875 FPS
-10F: MV 2710 FPS
_________________
165 FPS over 145 degrees F


77gr. SMK over MAX listed NATO pressure AA2520: (Highest MV of the 77gr. SMK over any propellant tested. Also the most temperature sensitive. I will not reshoot this loading at +135F)
+135F: MV 2950 FPS (Primers leaked on the last (2) rounds lowering the average. First (3) rounds were very consistent at 2987/2977/2983: Average of first (3) rounds: 2982 FPS.
-10F: MV 2767 FPS
_________________
183 FPS over 145 degrees F (If you use the average from the first (3) rounds at +135F, difference was 225 FPS over 145 degrees F)

But all the above is just worthless BS without groups, right?

77gr. SMK over NATO pressure H4895 fired from 18" 1x7.7 Krieger with M4 can MV 2739 FPS@100yds. off a not-too-steady wooden benchrest in trigger-pull conditions: I think this loading may have a bit more accuracy than I could demonstrate given the bench. Bottom line: The 77gr. SMK over NATO pressure H4895 loading clearly wants to group well.

 

[Thumper580]

For bolt gun... 22.0 gr IMR4895 with 73 or 77 match bullet. I get 1/4" or less at 100 yards in my Savage LRPV.

 

[2ndPanzer]

Leid,

IMR 8208 XBR is damn near short cut H4895. I think you'll like it. Meters like a ball powder but like H4895 in behavior. Except when you get close to the top end, then it's a small window from ok to dammit. 24.3 is ok but 24.5 blew primers. 24.0 is pretty stout, but not bad. 23.2-23.6 is a very good wide node that shoots great. Speed on par with H4895.
What were you using for your H4895 load? Also if you don't mind single loading or have a bolt gun with a long mag box, 75 VLD is awesome. Jump it .035 and use H4895, 24.2 in an AR or up to 25.0 in a bolt gun. .420 BC @ 3050 in a bolt gun is nothing to mess with. Shoots great too. Also 24.2 is a good 75 hornady mag length load as well. It's stout but damn it shoots good.

 

[leid]

2nd Panzer,
AFAIK, there is still no published data for a 77gr. SMK over 5.56MM NATO pressure H4895. So it is a judgment call to be made with a particular lot of H4895 in the individual rifle. I am interested in the mag-length 77gr. SMK & over-mag-length 80gr. VLD loads over 5.56MM NATO pressure IMR 8208 XBR. Same thing with no published 5.56MM data on 8208 either so I appreciate the top end warning. It is on my dance card but not much powder at the LGS yet. Will give it a spin as soon as hunting season is over assuming I can find some. One issue with H4895 VS spherical powders like TAC is you run out of room in the case quickly especially with long bullets. The ultra-long 70gr. TSX bullet over 5.56MM pressure H4895 is a real challenge just to assemble to mag length.

 

[steve123]

23.3 at 2.235" which was smack dab in the middle of the node with a 15" barrel.

 

[BoilerUP]

I believe the Southwest Ammo 77gr load is 23.8 XBR...

 

[leid]

The SWA 5.56MM 77gr. SMK loading showed very consistent MV/ES/SD numbers with extreme thermal stability. IMR 8208 XBR is supposed to be insensitive from -40F to +165F. I will have to take their word on that because this old dog is not ever going to be outside in those extremes to see any difference in MV. Below are the MV numbers on each of the (5) individual shots of the strings I fired to arrive at the thermal variation of 18 FPS over 145 degrees F (-10F to +135F).

SWA 5.56 77gr. SMK loading fired from 18" 1x7.7 SS Krieger/CLE barrel with M4 suppressor at 200FT MSL:

(HIGH TEMP)+135F: 2742/2769/2749/2729/2742: LOW: 2729 HIGH: 2767 AV: 2746 ES: 38.06 SD: 13.85 (HIGH AV - LOW AV) 2746-2728=18 FPS Thermal Variation Over 145 Degrees F
(LOW TEMP)///-10F: 2732/2737/2739/2722/2711: LOW: 2711 HIGH: 2739 AV: 2728 ES: 28.24 SD: 11.61