View Full Version : 18" rifle length 5.56, 55gr FMJBT, 8208XBR
Scored 1000 Hornady 55gr FMJ from Midway a couple weeks ago, and decided to work up a plinking load in my SPRgery with 18" Black Hole Weaponry 5.56 1:8 rifle length gas barrel. This rifle shoots the 77gr Nosler CC with 8208XBR very well; pretty much 23.4-23.8gr is MOA or better and 23.8gr matches or slightly exceeds velocity of Black Hills "white box" 5.56 77gr OTM Seconds.
Anwyay:
Control load: UMC 223 Remington 55gr MC. 10 shot average: 3000fps
LC-09
CCI-400
2.225" COAL
24.2gr 8208XBR: 2750fps
24.5gr 8208XBR: 2811fps
24.8gr 8208XBR: 2857fps
25.1gr 8208XBR: 2913fps
25.4gr 8208XBR: 2963fps (note: Hodgdon 223 Remington book max 25.3gr, no pressure noted at 25.4gr)
Accuracy? Disappointingly unimpressive. I wasn't really expecting a 55gr FMJ to shoot as well as a 77gr Nosler/SMK, but I was expecting better than 2.3" groups @ 100yd. The best accuracy of the group was the 25.4gr charge; it had least amount of vertical and discounting two fliers at 3 o'clock, 8 shots fell into 1.75".
XBR seems to perform best near max pressure (at least in my 223AI bolt gun), so I'll probably try another test with 25.2-25.8gr in 0.2gr increments.
Sounds like the barrel just doesn't like those bullets. But it could be the powder/bullet combo. Possibly a stout load of Benchmark could get you to about 1.5"
Also... a primer change can make a huge difference.
EEK!
Just finished the last of my TAC - and cleared the press to build out my XBR loads.
Was going to focus on 55gr Hornady and bulk Wideners 75gr.
Should have data in Tuesday PM.
Alaskapopo
05-01-13, 22:29
Scored 1000 Hornady 55gr FMJ from Midway a couple weeks ago, and decided to work up a plinking load in my SPRgery with 18" Black Hole Weaponry 5.56 1:8 rifle length gas barrel. This rifle shoots the 77gr Nosler CC with 8208XBR very well; pretty much 23.4-23.8gr is MOA or better and 23.8gr matches or slightly exceeds velocity of Black Hills "white box" 5.56 77gr OTM Seconds.
Anwyay:
Control load: UMC 223 Remington 55gr MC. 10 shot average: 3000fps
LC-09
CCI-400
2.225" COAL
24.2gr 8208XBR: 2750fps
24.5gr 8208XBR: 2811fps
24.8gr 8208XBR: 2857fps
25.1gr 8208XBR: 2913fps
25.4gr 8208XBR: 2963fps (note: Hodgdon 223 Remington book max 25.3gr, no pressure noted at 25.4gr)
Accuracy? Disappointingly unimpressive. I wasn't really expecting a 55gr FMJ to shoot as well as a 77gr Nosler/SMK, but I was expecting better than 2.3" groups @ 100yd. The best accuracy of the group was the 25.4gr charge; it had least amount of vertical and discounting two fliers at 3 o'clock, 8 shots fell into 1.75".
XBR seems to perform best near max pressure (at least in my 223AI bolt gun), so I'll probably try another test with 25.2-25.8gr in 0.2gr increments.
FMJ accuracy varies. My JP shoots Hornady FMJ's from 1.5 to 2 moa. However my Noveske Rogue Hunter does them from 2 to 2.5 moa. I have a theory on the Noveske's poligonal rifling causing more deformation on the open base design of FMJ bullets but its just a theory.
Pat
FMJ accuracy varies. My JP shoots Hornady FMJ's from 1.5 to 2 moa. However my Noveske Rogue Hunter does them from 2 to 2.5 moa. I have a theory on the Noveske's poligonal rifling causing more deformation on the open base design of FMJ bullets but its just a theory.
Pat
With 25.1 gr of 8208 XBR, a LC 09 case at 1.750", Tula SR .223 primer, and a Hornady 55 gr. FMJ-BT bullet at a COAL of 2.200", my average group is about 1 MOA.
Shot out of a personally assembled Noveske Afghan.
These are 100 yard 5-shot groups, and the average of 20-30+ individual groups now, spread over a couple of months. I've had groups as small as .6" ES and as large as 1.3" ES.
From my notes during my last range session. I was using the 55s to baseline a 69 gr Nosler load I've been working on.
Hornady 55 gr. FMJBT WC
1.750” LC 09
IMR 8208 XBR 25.1 gr.
Tula SR .223 Primer
2.200” COL
1) ES 0.831” (0.794) ATC 0.245” (0.234)
2) ES 1.216” (1.162) ATC 0.394” (0.377)
3) ES 0.975” (0.931) ATC 0.341” (0.326)
AVG ES 1.007” (0.962)
AVG ATC 0.326” (0.312)
All my shitty groups with the 55 gr. Hornady had much longer COALs. As soon as I put it at 2.200" per the Hornady 9th manual, it really tightened up.
Alaskapopo
05-02-13, 00:57
With 25.1 gr of 8208 XBR, a LC 09 case at 1.750", Tula SR .223 primer, and a Hornady 55 gr. FMJ-BT bullet at a COAL of 2.200", my average group is about 1 MOA.
Shot out of a personally assembled Noveske Afghan.
These are 100 yard 5-shot groups, and the average of 20-30+ individual groups now, spread over a couple of months. I've had groups as small as .6" ES and as large as 1.3" ES.
From my notes during my last range session. I was using the 55s to baseline a 69 gr Nosler load I've been working on.
Hornady 55 gr. FMJBT WC
1.750” LC 09
IMR 8208 XBR 25.1 gr.
Tula SR .223 Primer
2.200” COL
1) ES 0.831” (0.794) ATC 0.245” (0.234)
2) ES 1.216” (1.162) ATC 0.394” (0.377)
3) ES 0.975” (0.931) ATC 0.341” (0.326)
AVG ES 1.007” (0.962)
AVG ATC 0.326” (0.312)
All my shitty groups with the 55 gr. Hornady had much longer COALs. As soon as I put it at 2.200" per the Hornady 9th manual, it really tightened up.
Cool thanks for the info.
Pat
My Stag 3G with 18" SS barrel and rifle length gas system likes 24.5gr of 8208 in Winchester brass with CCI 400 primers and Hornady 55gr FMJ bullets. I usually can shoot 1.5-2" 10 round groups at 100y standing unsupported with a 3-9x40 scope on the rifle.
The groups get much tighter off of sandbags.
I'm still looking for an Afghan upper to finish my Noveske project.
[QUOTE=Thump_rrr;1649577] I usually can shoot 1.5-2" 10 round groups at 100y standing unsupported with a 3-9x40 scope on the rifle.
That is some fine shooting for unsupported 10 round groups.
I was just going to call bullshit and move on...
I was just going to call bullshit and move on...
I'm thinkin... I'm happy getting 2" groups with those bullets off a prone position...
But maybe this guy is an offhand machine. :confused:
I've had a lot of good luck with 55 gr Hornady FMJBTs in my Noveske. The average 5-shot group stretched across MANY groups hovers about 1 MOA.
This is with a Mark 4 2.5-8x on a bi-pod with a rear bag.
I don't think we've ever tried shooting a group with the Hornady 55s with a magnified optic. But I've definitely noticed that they shoot better than any other 55 gr FMJ.
Its surprising how accurate they can be. They can be a bit inconsistent, where you're doing everything right but getting bigger than expected groups. I consider that the nature of using open base FMJ bullets.
I'm still looking for a 69 gr. Nosler load with 8208 that shoots as well...
I ran another test with 8208XBR and 25.6gr with CCI-400 @ 2.20" COAL showed some life...10-shot groups were still in the 2MOA ballpark at 100yd with a couple fliers, but was overall more consistent with much less vertical than any other charge weight I tested.
I've been told a hotter primer than a CCI-400 might help accuracy; I'll probably load up 10 or 20 rounds with -400 and the same number with -450s to check accuracy.
In related 8208XBR news, I've settled on 23.5gr with a 77gr Nosler CC with this rifle; it provides about 2670fps and 0.6MOA accuracy on paper at 100 & 200yd. Probably won't win any competitions with it, but it has proven to be a reliable, consistent load more accurate than I currently am driving a gas gun.
I'm still looking for a 69 gr. Nosler load with 8208 that shoots as well...
Those bullet hang with matchkings with H322... haven't worked on combining them with 8208 yet though.
I've been told a hotter primer than a CCI-400 might help accuracy; I'll probably load up 10 or 20 rounds with -400 and the same number with -450s to check accuracy.
In related 8208XBR news, I've settled on 23.5gr with a 77gr Nosler CC with this rifle; it provides about 2670fps and 0.6MOA accuracy on paper at 100 & 200yd. Probably won't win any competitions with it, but it has proven to be a reliable, consistent load more accurate than I currently am driving a gas gun.
We've moved to 23.5 too for a test.... after popping primers at 23.8 on a different lot of 8208.
I'm interested in what you see with the primer experiment. Keep us posted.
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