BCL Bison, barrel twist, and ammo?

[randyhub]

Had my 5.56 Bison for a few months now, been tinkering with it, adding a few parts as well.

Being winter, thought I would try out some groups at the indoor range with my buddy today, as he was testing out his new TIKKA.

I removed the brake as I wanted ensure accuracy wasn't effected, used the bipod, monopod, tried 55 grain American Eagle, 62 grain WM reloads, 75 grain Hornady Match, and my buddy's 55 grain Dillon reloads at 48 yards.

While 48 yards isn't really a true test it has always given me an idea and a start as I am able to move outdoors and longer distances.

Found the barrel twist on my rifle did not like 75 grain Match ammo. While it grouped okay I was not impressed. The AE 55 grain and WM 62 reloads groups okay but not as I wanted either. Also was seeing a few weak ejections, emailed BCL within days I had new bolt parts, mug, and a patch, 5 minute swap now just flings the brass, this is the 3rd firearm I have had to swap bolt parts to address this issue,

But my buddy's 55 grain reloads shot really really well. Noticed if took my time between shots letting the barrel cool to the touch, the groups tightened. However I am torn between replacing my Bushnell AR scope with more magnification and MilDots, as my Athlon 24 power on my Savage has spoiled me.

Anyways here are my groups looking forward to stretching it out, any other Bison owners finding 55 grain bullets grouping better like me?



Mixed heavier ammo.




Oh, also reinstalling my blast diverter, and a few commented the fireball was friggin annoying.

 

[nitroxace]

I emailed Carrie at Black Creek Labs and here is the suggested ammo that they recommend. I can attest that the Winchester Varmit X 40 grain performs as advertised in getting repeatable 1.5 MOA or less at 100 yards.

Winchester Varmint X 223 Remington 40gr Polymer Tip
Federal Varmint and Predator .223 Rem, 53 Gr, Hornady V-Max
Nosler Varmageddon 223 Rem, 55gr Tipped Flat Base
Remington Premier Match 223 Rem 69 gr MatchKing Open Tip

Winchester Varmint X 223 Remington 40gr Polymer Tip is used at manufacturing facility to test fire and accuracy test.

All ammunition here has performed well under our advertised 1.5MOA with the 1:7 twist barrels.

 

[beltfed]

I did some testing back around December of 2021 into this time last year with mine with it's original 1:7 twist barrel and then with a replacement 1:8 that BCL replaced under warranty.
Any factory ammo I've fed it hasn't been promising - like 3+ - 5" groups at 100m at best. It got to the point I was tearing my hair out looking and revisiting rail and scope mounting to ensure nothing was loose. I tried typical factory FMJ like XM223 55gr., IVI 62 gr., PMC X-tac 62gr., Hornady Black 62gr., AE223 55gr. FMJ - all of it shot like crap and not worth keeping records of the groups (think minute of pie plate, if that at 100m with 5 rounds).

Of the factory ammo I shot and the groups I kept:

- Blackhills 75gr. Match factory ammo - 5 rounds at 100m - 5"
- Hornady 55gr. Steel Match - 5 rounds at 100m - 3.5"
- Hornady 75gr. HPBT Steel Match - 5 rounds at 100m - 4"
- Frontier Hornady 55gr. Match - 5 rounds at 100m - 4.5"

I had some decent success (under 2", 5 or 10 round groups at 100m) with a boat load of handloads I still have from my service rifle competition days, especially with 69smk, 77smk and 60 gr HPs, so my intention was always to revisit handloading specifically for this rifle.

Didn't get to it last summer, so hopefully this year.

I think BCL are doing fantastic things with respect to warranty, and this design is pretty cool all-round, but the barrel is the heart of this rifle and I personally think it is the biggest let-down on this platform.

 

[nitroxace]

Beltfed thanks for your info. I agree that Black Creek has an exceptional warranty and customer service. I just returned from my LGS and I will be testing Federal Varmint and Predator .223 Rem, 53 Gr, Hornady V-Max as they recommended. I also grabbed a few more boxes of the Winchester Varmint X 223 Remington 40gr Polymer Tip as it worked very well.

 

[beltfed]

I'm going on a hunch that BCL are re-using or re-purposing barrels they have in stock that maybe they had left over from past AR building, maybe?

There isn't much excuse to use such mediocre barrels otherwise in my opinion.
If they sourced and installed decent barrels to begin with, guys would be printing sub-moa 5 round groups with ease, raving about it and they would be flying off the shelves - imho.

 

[Kranger_Rudy]

Yeah. I really want to like this rifle, but a chassis gun with a nice aftermarket trigger geting it's butt kicked by a Ruger in a plastic stock is pretty weak IMO.

 

[FatCatsDad]

It's definitely not a target rifle, rem 700 or Ruger m77 is far more accurate, but it looks like it's marketed as a rifle to pack and go with you.
I don't think this is a range gun.

This twist chart from the NRA seems to indicate these Bison barrels would be better with a heavier projectile

 

[beltfed]

It's definitely not a target rifle, rem 700 or Ruger m77 is far more accurate, but it looks like it's marketed as a rifle to pack and go with you.
I don't think this is a range gun.

This twist chart from the NRA seems to indicate these Bison barrels would be better with a heavier projectile

The barrels are floated in the chassis, and they are a medium to medium-heavy weight in thickness comparable to the .223 cartridge. The short barrels on these (12.5 and 16.5" lengths) should mean they shoot most everything well in this caliber at short range.
The fact they don't lends me the belief they have taken shortcuts, or sourced poor quality barrels.
If the likes of other established manufacturers can fit up cold hammer forged barrels and sell their rifles at considerable savings to the Bison, surely BCL can source some decent button or cut rifled barrels.

And btw, take that graphic with a grain of salt - it is very generic at best and out to lunch at worst.