223 Service Rifle & 8208 XBR question:

[stevewix]

Looking for first hand experience here. I ladder tested 8208XBR with 75 Hornady BTHP moly bullets, CCI Arsenal primers in LC09 cases. Started at 21.5gn and went to 24gn. I hit a small node from 21.8gn to 22gn, roughly 2600fps, other than that my test across two White Oak Service Uppers came out inconclusive. I've heard nothing but rave reviews, but this stuff seems much too fast for 75/80gn 223 loads. Thoughts?

 

[areaone]

IMR 8208 works well with 69SMK for my AR and 223 AI, very accurate. Never tried it with anything heavier, I would think Varget or RL15 may be better with the heavy bullets.

 

[mac86951]

I think the key is your WOA upper. I too have a WOA upper, in rifle length and it is way over gassed. I love it, and I love WOA, but it is pickier about powders, and it is harder to tune the gas system. Being a service rifle, there is little to do about modifying the system (buffer/spring/BCG/Adjustable gas block) that you are allowed to do. Also, my WOA isn't a fan of the Hornady 75gr HPBT, where I found a small node of 2650fps, however, it loves the 77gr SMK and JLK bullets.

In my over gassed WOA upper, 8208 does well, as does TAC and H335. I'm using non-moly'd bullets loaded to mag length.

My WOA does LOVE Varget, N140, AR-Comp, and other slower powders too. What distance are you ladder testing?

I had overlapping ladder "rungs" within 300y with the 77Sierra. I had to do ladder testing at 450y to see the difference, then verify with 200y groups.


-Mac

Oh, and it is possible that the powder is too fast for your rifle. If you notice AR swipe before flat primers, this is probably the case, and a slower powder is the ticket.

 

[Browning243]

I shoot an all factory Sig M400 with 16" barrel off the Walmart shelf. I've tried XBR and Varget behind 55 grain bullets. The XBR did ok but Varget did better. There was good results in the midrange loads with the XBR. Don't remember exact charge. The Varget did as well as the mid range loads of XBR thought the full range. But best results were in the mid to high range. More less what this accounted to is I'm getting better accuracy and velocity out of Varget then the XBR.

But XBR was designed for 223 service rifles. If you notice most all service rifle load data is 68-70 grain bullets. Food for thought.

 

[stevewix]

IMR 8208 works well with 69SMK for my AR and 223 AI, very accurate. Never tried it with anything heavier, I would think Varget or RL15 may be better with the heavy bullets.

What charge weight and velocity are you seeing?

 

[BoilerUP]

23.8gr 8208XBR
77gr Nosler CC
CCI-400/450/Rem 6.5
RP brass

2683fps from a 18" 1:8 Black Hole Weaponry rifle-length gas 5.56 barrel with half-MOA accuracy

 

[ar10ar15man]

yep i think you will find it works great with light bullets for short range...not so with the heavies.

i have shot oem 8208...original mil surplus in br ar...works grat with 52/53 gr bullets.

xbr is just a little off of oem but not enought for the heavies.

 

[BoilerUP]

23.8gr 8208XBR
77gr Nosler CC
CCI-400/450/Rem 6.5
RP brass

2683fps from a 18" 1:8 Black Hole Weaponry rifle-length gas 5.56 barrel with half-MOA accuracy

Verified this velocity today over 20 rounds via chronograph and dope out to 450yd.

For comparison's sake, Black Hills 5.56 77gr OTM Seconds chronographed at 2648fps today. 24.0gr Varget with 77gr Nosler CC provided 2521fps, and 24.4gr Varget 2567fps.

 

[Citysmasher]

23.8gr 8208XBR
77gr Nosler CC
CCI-400/450/Rem 6.5
RP brass

2683fps from a 18" 1:8 Black Hole Weaponry rifle-length gas 5.56 barrel with half-MOA accuracy

That is pretty hot. Don't use soft primers... hahaha

 

[BoilerUP]

[quote author=Citysmasher]That is pretty hot. Don't use soft primers... hahaha
[/quote]

Hot compared to Hodgdon 223 Rem data? Yes. Zero pressure signs in my 5.56 gas gun. CCI-400s and Rem 6.5s work just fine...

 

[Citysmasher]

[quote author=Citysmasher]That is pretty hot. Don't use soft primers... hahaha

Hot compared to Hodgdon 223 Rem data? Yes. Zero pressure signs in my 5.56 gas gun. CCI-400s and Rem 6.5s work just fine...
[/quote]

It is not hot yet. I was piercing primers with CCI 400 at 24.5 in the summer.

Of course mine is from the VERY FIRST lot. I heard it was faster.

 

[BoilerUP]

[quote author=Citysmasher]It is not hot yet. I was piercing primers with CCI 400 at 24.5 in the summer.[/quote]

Highest I tried was 23.8gr. Seems some folks find a node with 77s at 24.0gr in a 5.56 or Wylde chamber, but 23.8 shoots well so its "good and fast enough".

I have heard XBR is "spooky" with regards to pressure - it goes from showing no pressure to piercing and blowing primers in just 4-5 tenths of a grain.

I've also heard its temp insensivitiy is akin to Varget. Guess I'll find out in the coming months...

 

[ar10ar15man]

i would not reccommend anyone use this load without working up in YOUR GUN.
this load shows excessive high pressure in QUIKLOAD.......
IF A PLAY WITH ENERGY to get down to his velocity, it is still 60kpsi.......

approach with caution....

23.8gr 8208XBR
77gr Nosler CC
CCI-400/450/Rem 6.5
RP brass

2683fps from a 18" 1:8 Black Hole Weaponry rifle-length gas 5.56 barrel with half-MOA accuracy

 

[BoilerUP]

i would not reccommend anyone use this load without working up in YOUR GUN.

I wouldn't recommend anyone using that load (or any load sourced on the internet, for that matter) without working it up in their specific weapon.

 

[Longtrain]

23.2 of 8208, Wolf SRM and 77 SMK's or Nosler's just hammer from either my Tikka 595 or my WOA Space gun. I get very similar results from TAC, which is close to the same burn rate. YMMV of course.

 

[Maxden]

I am getting amazingly unbelievable velocity with a 28” barrel. Lapua cases 23.6 8208xbr
80.5 Bergers Fullbore. 2,920-2,940 No obvious signs of pressure either? Bolt gun built as a trainer

 

[searcher]

I think the key is your WOA upper. I too have a WOA upper, in rifle length and it is way over gassed. I love it, and I love WOA, but it is pickier about powders, and it is harder to tune the gas system. Being a service rifle, there is little to do about modifying the system (buffer/spring/BCG/Adjustable gas block) that you are allowed to do. Also, my WOA isn't a fan of the Hornady 75gr HPBT, where I found a small node of 2650fps, however, it loves the 77gr SMK and JLK bullets.

In my over gassed WOA upper, 8208 does well, as does TAC and H335. I'm using non-moly'd bullets loaded to mag length.

My WOA does LOVE Varget, N140, AR-Comp, and other slower powders too. What distance are you ladder testing?

I had overlapping ladder "rungs" within 300y with the 77Sierra. I had to do ladder testing at 450y to see the difference, then verify with 200y groups.


-Mac

Oh, and it is possible that the powder is too fast for your rifle. If you notice AR swipe before flat primers, this is probably the case, and a slower powder is the ticket.

Might be an anomaly, but I have a WOA upper in .22 Nosler, as does a buddy (we bought at the same time) and we get swipe marks no matter what powder is used unless dialed back to less than.223 speeds. I finally just disassembled the bolt and felt the edge on the extractor. It was like a razor blade - much sharper than any I have run my thumb across before. I buffed the edge with a dremel tool and reassembled. No more swipe marks. You are right about them being a bit over-gassed. Very accurate though. An extra power Wolff mainspring helped too - if you can use it in your discipline.