Accuracy of your SBR 300 Blackouts

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hardcase
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Re: Accuracy of your SBR 300 Blackouts

Post by hardcase » Thu Feb 02, 2017 2:21 pm

EternlYs,

Just curious. The ammo can says 7.62x39. Is the rifle a 300 Black?

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TKO
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Re: Accuracy of your SBR 300 Blackouts

Post by TKO » Wed Mar 01, 2017 3:16 pm

I would love to have the details on that build, please.

riude
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Re: Accuracy of your SBR 300 Blackouts

Post by riude » Fri Mar 03, 2017 10:16 am

Nice group. How many rounds can you shoot before flyer?
And can you shoot first round after barrel cleaning to same group?

I have bolt action, made from Weatherby vanguard .223.
In extremely calm weather, it can shoot about 1 moa constantly.
But must allways shoot 1 "grease shot" after cleaning, it will be anywhere 2-3" away.

EternlYs
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Re: Accuracy of your SBR 300 Blackouts

Post by EternlYs » Sat Apr 08, 2017 11:33 pm

TKO wrote:I would love to have the details on that build, please.
700 action, did the barrel work and bolt myself. Made my own break to index off the crown. Whiskey 3 chassis from krg, sis the cerakote in coyote tan, silencerco radius for quick ranging and gold over for subs out to 250. Viper PST 4-16x50... also, I generally don't clean between rounds, only after a session, it's integrally supressed, form 1 built myself as well.

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Re: Accuracy of your SBR 300 Blackouts

Post by MisterHelix » Sat Apr 15, 2017 4:04 pm

Subsonic 300aac at 100 yards

Rifle:
Noveske 10.5" SBR
Specwar 762
Aimpoint T-2
H2 buffer
Geissele SSA
Image

Load Data:
Nosler 168 custom competition
IMR4198 @ 11 grains
CCI 450
OAL = 2.11"
LC converted brass

Notes:
Rifle zeroe'd for ~supersonics~ at 50 yards. Subsonic load POI with this zero is ~7" low at 100y. Targets were shot with top target as POA, lower target received POI, after two groups, target turned over.
Four five round groups
Image

#2 and #4 both have a flyer that impacted about 2" low from the rest of the group. Maybe I pulled it, or maybe not. I dunno.

Overall, it looks like I'm seeing about 1.25 MOA (excluding the flyers). Including the flyers, perhaps 2.5 or 3 MOA.

Could this be improved with magnified optics? I think so.

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dellet
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Re: Accuracy of your SBR 300 Blackouts

Post by dellet » Sat Apr 15, 2017 4:38 pm

MisterHelix wrote:Subsonic 300aac at 100 yards

Rifle:
Noveske 10.5" SBR
Specwar 762
Aimpoint T-2
H2 buffer
Geissele SSA
Image

Load Data:
Nosler 168 custom competition
IMR4198 @ 11 grains
CCI 450
OAL = 2.11"
LC converted brass

Notes:
Rifle zeroe'd for ~supersonics~ at 50 yards. Subsonic load POI with this zero is ~7" low at 100y. Targets were shot with top target as POA, lower target received POI, after two groups, target turned over.
Four five round groups
Image

#2 and #4 both have a flyer that impacted about 1.5" low from the rest of the group. Maybe I pulled it, or maybe not. I dunno.

Overall, it looks like I'm seeing about 1.25 MOA (excluding the flyers). Including the flyers, perhaps 2.5 or 3 MOA.

Could this be improved with magnified optics? I think so.
It might have been the munitions department that let you down. :oops:
You're probably closer to a 30-35 yard zero with subs and 25 fps lower will get -3/4" or better at 100.

Still, <1.5" at 100 with subs is pretty good shooting and loading.
300 Blackout, not just for sub-sonics.

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Luke2236
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Re: Accuracy of your SBR 300 Blackouts

Post by Luke2236 » Sat Apr 15, 2017 5:28 pm

cmcleod wrote:With factory ammo, I have found several rounds that my Odin 10.5" shoots well, and some that it doesn't.

For supers it loves Remington Premier Match (sub MOA), and it likes Remington UMC 120 and Barnes 120 decently (1.25" or better). Barnes 110's don't do as well (1.75" sometimes a bit better).

Subs, I have not and probably will not hit consistent MOA with a factory load (for the reasons stated previously), although the remington 220's (green and yellow box, not the UMC) have surprised me a few times, as well as stuff from Gorilla. The gorilla Silverback subs have been .75" at 50 yards, which is plenty for me for close range deer hunting.

Reloading is in my near future, mostly for the quest of an accurate, expanding sub load for hunting a bit further out.
Nice to know, my present build is centered around and OW 10.5" barrel.
Canadian Coast Guard - Retired

MisterHelix
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Re: Accuracy of your SBR 300 Blackouts

Post by MisterHelix » Sat Apr 15, 2017 5:46 pm

dellet wrote: It might have been the munitions department that let you down. :oops:
You're probably closer to a 30-35 yard zero with subs and 25 fps lower will get -3/4" or better at 100.

Still, <1.5" at 100 with subs is pretty good shooting and loading.
The load itself is adequate for my uses. (Higher-round count close quarters drills without pissing off the neighbors).

My only complaint is that the IMR 4198 doesn't meter well.
I'll likely re-zero it with the subs when the stamp comes in for my Omega9k, and run it dedicated suppressed subsonic.

I guess I don't really understand why it's so easy to load ~very~ accurate .308win, while similar efforts produce..."meh, ok" ammo in 300blk.

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Re: Accuracy of your SBR 300 Blackouts

Post by jwb47 » Sat Apr 15, 2017 10:23 pm

strictly speaking for my 8.5 inch cmmg only with nosler 110 grain varmageddons and an aimpoint pro right at 1.5-2 moa at 100 yds if i try real hard , but its good enough to do this at 75 yds and I am content with that.


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dellet
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Re: Accuracy of your SBR 300 Blackouts

Post by dellet » Sat Apr 15, 2017 11:30 pm

MisterHelix wrote:
dellet wrote: It might have been the munitions department that let you down. :oops:
You're probably closer to a 30-35 yard zero with subs and 25 fps lower will get -3/4" or better at 100.

Still, <1.5" at 100 with subs is pretty good shooting and loading.
The load itself is adequate for my uses. (Higher-round count close quarters drills without pissing off the neighbors).

My only complaint is that the IMR 4198 doesn't meter well.
I'll likely re-zero it with the subs when the stamp comes in for my Omega9k, and run it dedicated suppressed subsonic.

I guess I don't really understand why it's so easy to load ~very~ accurate .308win, while similar efforts produce..."meh, ok" ammo in 300blk.
Start your .308 project by collecting a bunch of 300 Savage range brass and convert it to .308. Chamber your barrel with an oversize reamer so you can use the thickest brass you might find and give it a jump to the lands equal to about 45k firings. Choose your powder based on if it will cycle the action designed to run at a higher pressure instead of accuracy. Then spin your bullets outside of their ideal rate.

When you get to the range remember that with the 300 blackout compared to a .308, your 100 yard shot will mimic the last 100 yards of a 308 at around 3-500 yards depending on your bullet choice with supers, with subs it will mimic the trajectory of the last 100 yards of about a 1200 yard shot.

On a serious note, it just takes a little more effort to get good results. Part of that is experience with the cartridge. Folks are really just now starting to figure it out. It suffered an undeserved reputation early on as under powered and inaccurate. Under powered is more or less true, until you look at what you are actually getting out of a pretty small case and a really big bullet. Inaccurate because a lot of serious shooters think it's a joke of a cartridge and don't put any effort into it.

Guys working with bolt actions or single shots are getting some very impressive results, the AR's really aren't too far behind. The people who get very good results with an AR 10, aren't using the cheapest parts for the rifle they can find and assembling cartridges as described above.

You might see some better results moving to any of the bullets that work well in the service rifle classes. They are designed for long jumps in magazine fed rifles and the chamber for the Blackout was actually designed for running 220 SMK at .010 off the lands. Both the 155 Palma bullets and the 175 SMK have proven very reliable for me. The 175 SMK works very well as a sub as well as super.

Another good bullet is the Hornady ELD line. Not enough time with it yet, but so far looks very forgiving to load.

With your shorter barrel you can run some much faster powders. They will likely be more consistent, and will certainly be quieter than what you are using now.

Just some thoughts but there's a couple folks around here that shoot consisent 1.5 MOA or less out to 300 yards. The vertical string is what is the hardest thing to conquer.

I think from your targets posted, a better optic and maybe tightening up your ES (assuming it's more than 20) you might just be pleasantly surprised.
300 Blackout, not just for sub-sonics.

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