8.6 Blackout +P+ musing

and other thoughts from the hills of the American West

Last Night, Walter wrapped up his 2024 hunting seasons, bringing back to his MILF mobile, a Lexus GX460, nothing more than a big smile and wet socks.   For the last month and a half, Walter has been traversing the American West searching for ungulates, with the hopes of taking game with some certified pissing-hot, warranty-voiding loads.  In Colorado, Walter shot a cow elk at 766 yards with a 308 16-inch Q Fix with a Noveske prototype barrel. In Wyoming,  Walter took a Calf at 450 yards with a 200 grain Discreet Ballistics projectile loaded in converted 8.6 brass.  Both kills happened near instantly, with the animals moving less than 50 feet.  The cow dropped like a 7-10 split. The calf elk,  shot through the heart, sat down and never got up.  Walter's hypothesis for this hunting season was this:  in the age of modern projectiles, powders and hybrid brass,  a bowler does not need the 24 inch 300 win mag to successfully hunt big game.  All of Walter's hunts involved a fair amount of packing and Walter's beloved Q Fix rifles with a 12.5 8.6 Factory Barrel, and Prototype Noveske 16 inch 308 barrel felt light in hand and weren't even noticeable when strapped to the pack. 

Converting and loading 308 from 2.77 Furry brass is very straightforward.  Just use a full length sizing die,  fireform with a light load,  then jam as much powder in there as you can and trim after a few firings.  8.6 on the other hand required far more work to convert, and a lot more trial and error to get a recipe that gave Walter the performance benchmarks he wanted.  Today we will focus on 8.6,  its loadings, and some musings from the range and from the hills.  Here are some observations after putting hundreds of rounds of hybrid supers down the tube:

Pistol powders are not the most effective propellants for 8.6 Blackout suppers,  H110 and Lil Gun spike pressures too high and lead to heavy bolt lift.  8.6 is not just a scaled up 300 blackout,  it is its own animal and needs to be treated as such.  Walter has had the best luck with h335, which is a powder often used for 223/556 and varmint cartridges. 

Lighter projectiles, whether subsonic or supersonic, tend to group the best. Sure a 350 subsonic grain projectile has the best performance on paper, and a 210 doing 2150 is a freight train at 100yds but unless you can hit what you're aiming at the added weight isn't worth the cost of accuracy.  Walter has had the best luck with 185 grain CX and the 200 grain Discreet projectile when it comes to balancing accuracy, energy and ballistic coefficient with his best group being in the 1 MOA range.   Existing lighter projectiles don't have boat tails and aren't worth Walter's time.

Spin drift is substantial with the 1/3 twist, accounting for a full one mil at 500 yards.  It is however predictable and needs to be documented and accounted for like an elevation hold.

For a given powder charge, barrel length and recoil,  8.6 supers, with hybrid brass, are unmatched at providing downrange lethality in a small package, all while retaining subsonic performance. The 200 grain Discreet Ballistics projectile entered by the front shoulder and exited by the ass,  piercing the heart and penetrating an entire calf elk. Before anyone asks,  Walter would like to say a few things about 338 ARC.  First of all, think of 338 ARC as an American equivalent to 9x39.  It is in effect an amazing subsonic, submachine gun round.  The case capacity is just too small to get a supersonic projectile moving at speeds that would ever allow it to do what 8.6 blackout can do.  There's not a hypothetical situation,  not even on top of Mt Everest, where it would make sense to shoot an elk at 450 yards with 338 ARC supers. Their offering of 175 grain OTM, does 1950 out of a 16 inch gun with a bullet that more closely resembles a pistol projectile, than a modern hunting bullet. The decision to go with a 1/8 twist rate is insane and must be fuck you to Q,  expect to see barrel manufacturers turning this up.  For subs, in a gas gun it will be a hoot, but it has a fraction of the utility that 8.6 Blackout has.

Now back to 8.6.  To Walter,  the future of 8.6 will hinge on its ability to offer bowlers an incredibly flexible and effective hunting platform.  For a given barrel length and charge,  8.6 will be more efficient out of a short barrel than say 308, and will retain more rotational energy downrange.   The issue now is that most projectiles bowlers are loading for 8.6 supers are optimized for 338 magnum.  We need lighter projectiles in the sub 180 grain category with high ballistic coefficients and metal compounds designed to expand down to say 1400 or 1500 FPS with a 1/3 twist.  Legacy bullet manufactures like Hornady and Barnes have already voted, and it will be up to smaller, boutique manufactures to drive innovation here.   8.6 Blackout isn't for everyone, but with hybrid brass, it takes an interesting proposition and turns it into the most flexible rifle in Walter's arsenal.  With some continued optimization and a good range call, Walter would feel confident shooting an elk at 500 yards with 8.6,  that's out of a 12.5 barrel mind you.   Right now a bowler's options are converting 2.77 Furry brass, but rumor has it that Shell Shock is coming out with hybrid 8.6 brass.   If you will it, it is no dream!