8.6 Blackout 1:3 twist cast boolits are possible!!!

[HillbillyNC]

Not looking to start a discussion on the merits of the cartridge. This is an exciting time, being at the beginning of something that challenges traditional wisdom. A very few folks have begun to work with cast in the 1:3 twist barrel. There is a very detailed work up on one of the 8.6 Facebook groups that shows the cast boolits holding together until 1115fps with a 24bhn alloy but the poster declined to share the alloy ingredients/percentages. The mold used was a 338 dia 270 grain NOE spire point with no lube grooves. I would like to also do some cast experiments but wanted to get a heavier, flat point mold to work with. NOE has already manufactured, but is currently out of stock, the HTC339-315-FN-BZ1 315gr flat point. There is currently a post on the NOE forums directed at getting NOE to make more of these. Apparently the mold was originally designed for the 338 Specter but will also work in all 338 cal applications.

If you are interested in a 338 mold, and this would work for you in your pursuits, could you please sign up on the NOE forums page?

HTC339-315-FN-BZ1

[waksupi]

At 1 in 3 twist rate, that isn't a rifled barrel, it's threaded!

[Larry Gibson]

At 1 in 3 twist rate, that isn't a rifled barrel, it's threaded!

No kidding........

[725]

Oh, my. That bullet must be hard and slow to survive a 1/3 twist.

[HillbillyNC]

At 1050fps, that's a mere 252000rpm.... But it's being done with success. I myself am looking forward to playing around with this and trying to leverage all the old wisdom and tricks to get it to work. Instead of hardening up the alloy to point of brittleness, my 1st experiment will be with copper infused alloys in order to lower the bhn and maintain bullet integrity. Ideally it would be awesome to have a subsonic 315gr flat point with the 1:3 twist that expands. The fast twist should go a long way toward expansion if you can strike the balance.

[dondiego]

What is there to gain from this twist?

[Dusty Bannister]

Pistol velocities from a rifle? Maybe it is just to see if it will work and how fast can it go with present technology and practices.

[Hanzy4200]

That caliber really interested me when I first saw it. I know I will need to be patient, and wait for more main stream manufacturers to offer rifles chambered in it. I know very little about it. Is there a parent case that in can be formed from?

[Hanzy4200]

Pistol velocities from a rifle? Maybe it is just to see if it will work and how fast can it go with present technology and practices.

It's designed to be shot suppressed. Like a larger .300 Blackout.

[technojock]

Wouldn't a .38 Special or 9mm carbine make more sense? They already shoot a boolit around 125g at subsonic speeds.

Tony

[kenton]

Wouldn't a .38 Special or 9mm carbine make more sense? They already shoot a boolit around 125g at subsonic speeds.

Tony

It would if you wanted 125gr boolits instead of 315gr.

I think the 8.6 blackout is an interesting idea. Not my cup of tea but I hope to hear more about what others are doing with it.

[stubshaft]

Personally, I think it is a waste of time and money, but to each their own.

[ebb]

I totally agree stub shaft. JD jones has been shooting 338 subs for years and never saw the need for the extremes that this cartridge is coming up with. I don't see how this survives for 2 more years. How much drop does this thing have at 200 with a 100yd zero. We are spoiled with the high-performance cartridges we have today and this is so low performance I don't see why anyone would bother. One of the guys that posts on bench rest central developed a sus sonic 50 caliber, with a super long sleek bullet and it was great only he couldn't stand the recoil for more than a shot or two.

[technojock]

Doesn't the .45 Colt shoot about a 300g bullet at subsonic velocity?

Tony

[475AR]

While I am not planning to jump on the 8.6 Blackout bandwagon, I think using cast bullets in that fast of a twist will cause accuracy issues with cast bullets, but it needs to be tested to be sure.
I have heard that using standard jacketed/ lead core bullets is cautioned against because they could blow up in flight, if that is true I don't think lead only bullets will be much better??

[Castaway]

Another designer cartridge and the only apparent advantage is to sell rifles. If you get one, you may find a spot for it in your safe next to your 45 GAP pistol

[Barry54]

What is there to gain from this twist?

They talk up the ridiculous twist being more effective on game. I would try one with a twist rate optimized for the 300 grain matching subsonic.

Are there any gel comparisons between subsonic with the 1:3 vs what JDJ used?

[475AR]

Another designer cartridge and the only apparent advantage is to sell rifles. If you get one, you may find a spot for it in your safe next to your 45 GAP pistol

Why everyone b hating on the GAP...
I built a 10" DI AR15, throated it to run 250gr bullets @ 850-950fps and it shoots beautifully and to top it off it is the quietest 45 caliber I have suppressed.
It is so surprising I have KKM building me a 7" 45 GAP threaded barrel for my long slide G21, hopefully it will be as quiet as MY GAP AR15.

[reddog81]

Doesn't the .45 Colt shoot about a 300g bullet at subsonic velocity?

Tony

Sure, but the rifle bullet is more aerodynamic. It'll retain velocity better, and have less drop over a given distance. And you can't shoot a 45 Colt out of a semi auto rifle.

[technojock]

It still seems like an answer in search of a question...

Tony