What the hell is a 8.6 Creedmoor

Appears to be a .338 that is designed to shoot subsonic out of .308 magazines, based on a quick internet search. If you are going for the bigger platform, I don't understand why you would be interested in a close-range round. Blackout in an AR15 makes sense for CQB, but if I have an AR10, I want a rest, and a round that will take advantage of it.

Was that a typo re, the muzzle energy? If not , my 357 mag has more energy than the 8.6 !

At 500 yards silenced?

J.D. Jones, dba SSK, has offered the .338 Whisper AR10 for some time.
But if we toot this outfit's horn loud enough their version just must be new and improved.

It seems like its 300 BO for a AR-10 size platform. The only thing you should need to change is the barrel. It will probably feed from a standard 308 magazine. It seems like 338 Federal with the shoulder push back to optimize if for heavy subsonic loads.

nhcruffler said:

Was that a typo re, the muzzle energy? If not , my 357 mag has more energy than the 8.6 !

Click to expand...

I don't think your getting 2100 ft-lbs from a 357 Magnum even in a carbine. And if your referring to the 650 ft-lbs number that is subsonic and is pretty respectable for a subsonic energy level and again I don't think you can get that type of energy from a 357 Mag at subsonic velocities though you can probably get closer than the super sonic numbers. But with 338 bullets you can get that subsonic level of energy with bullets that are significantly more aerodynamic that most heavy weight 357 Magnum bullets so in theory it would be a good long (well medium long) range subsonic cartridge.

More options for same platform= good!
Sounds fun with a surpressor to me

Hmm that has my attention. I’d never heard of the 338 whisper. Only bad thing is needing a .338 can for it.
I was going to build a 5.56 sbr, but maybe this is the answer if it will really shoot 600 yards suppressed with 500#

I know it’s a nitch gun, but for a reloader, caster, varmint hunter like me it sure sounds like the ticket. I have some blackouts and they are 100-200 yard guns on hogs.

If I can get a bullet mold and it’s possible to form it from 308 brass I may be in on this one. Out on buying sky high niche components or factory ammo.

mcb said:

It seems like its 300 BO for a AR-10 size platform. The only thing you should need to change is the barrel. It will probably feed from a standard 308 magazine. It seems like 338 Federal with the shoulder push back to optimize if for heavy subsonic loads.

Click to expand...

Exactly. The shoulder is positioned for heavy subsonic loads.

nhcruffler said:

Was that a typo re, the muzzle energy? If not , my 357 mag has more energy than the 8.6 !

Click to expand...

Your 357 Mag puts out 2,100 Ft. Lbs. of energy at the muzzle? I'd like to have one of those!

So basically it is to the .308 what the .300BO is to the .223. Sounds interesting. Especially if it works and we see some .338 bullets that will expand at subsonic velocities. Took a while to get those for the .300.

The hard parts going to be dialing the thing up. I played with the ballistic calculator. It falls like a rock! 90 moa at 600! Someone’s gonna have to build a 50moa Mount!

I just don't get the appeal of subsonic rifle rounds. But, to each their own.

P

ATLDave said:

I just don't get the appeal of subsonic rifle rounds. But, to each their own.

Click to expand...

you need to go predator hunting with one. Your shots are a necessary evil of hunting. We try to hide ourself, our scent, but in the past the shot was a necessary evil to blow your cover. Subsonic round suppressed “camoflauge” your shots. So you can shoot that second coyote or not get every dog for 3 miles on high alert.
They work in deer leases too where you have buddies hunting close enough that your shot may ruin their hunt. Mind you not totally silent, but a hearing safe supersonic suppressed round confuses animals at 3-400 yards. Suppressed subs confuse animals at as little as 100 yards or less.

it to slow for most 338 bullets to open good. even the 338 fed runs into this. tho id like to do a 338 fed one day

ATLDave said:

I just don't get the appeal of subsonic rifle rounds. But, to each their own.

Click to expand...

I can't figure it out either. For the longest time the trend was for more velocity. Now there seems to be a trend for less. The goal, a 500 grain bullet moving at 1000 fps. Truck gun that quietly kills trucks.

It's a specialized tool that does a specialized job. It's perfectly legal to shoot where I live but the suppressor keeps me on good terms with the neighbors. It's also fun and convenient to hunt without hearing protection or going deaf. If all you need to cover is 100yds, there are no drawbacks. Unlike all my other 100yd guns, it has the capability of reaching out to 300yds with a change of loads.

BigDog1955 said:

Whttps://www.gunsamerica.com/digest/8-6-creedmoor/?utm_source=email&utm_medium=20180910_BlogDigest_294g&utm_campaign=/digest/8-6-creedmoor/ow

Click to expand...

somethings that bloated big and fat and crawls along slow like a turtle and drops like a rock after a few hundred yards

Hmmm, sounds like a 358 Winchester... And that is already the right bore for subsonic pistol bullets... Are these offered in tight twist barrels to stabilize the big guys? Couldn't read the article, the link wouldn't open for me. Btw, wouldn't a 375 socom kinda do the same thing with similar relative accuracy?

Sam T1 kind of answered a question I had about the round. How much that thing is going to fall at distance. I think a lot of development is going to be needed.

Call me crazy but I just don’t see the point in building a round specifically for subsonic in an auto loader. You can do the same thing in a manually operated gun by bumping up the bullet weight and dropping to powder charge. I see some merit as a machine gun but it’s minimal because body armor should be pretty effective at stopping subsonics. I don’t see it in an ar15 and I certainly don’t see the point in an ar10 platform. 30/30 lever carbine shooting 250gr slugs or some similar configuration, maybe. Dropping down to something like an Uzi or mp5 type gun I could see, but not in a large rifle flatform. If the goal is big, fat, subsonic powerhouse then they need to look more into something resembling a 44 automag round in a small weapon package...mechtech glock system with a lengthened mag well or similar.

troy fairweather said:

it to slow for most 338 bullets to open good. even the 338 fed runs into this. tho id like to do a 338 fed one day

Click to expand...

Same was true a few year ago with 300 BO subsonics. Now there are several good reliably expanding bullets for sub sonic 300 BO. I am sure those same makers will offer subsonic 338 bullets if this cartridge gains even a little traction in the market.

ETA I just looked and Maker Bullets is already making a subsonic 300gr expanding .338 diameter bullet.

http://makerbullets.com/products.php?cat=3&scri=119

Ever looked at expandable 458 subsonic bullets? They work great but cost about $2 a pop for the projectile. Or use soft lead for 30 cents. ALL 338 bullets are for fast, hard hitting cartridges, it seems strange to me to build a subsonic cartridge based on these bullets. And in an ar10, even less desirable to me. Especially with the existence of the 358 win,375 raptor, and 45 raptor already out there. Maybe someone has a bunch of blem 338 bullets and too much time to kill...

https://www.wholesalehunter.com/Product/Details/11229169

This bad boy! No need to buy bullets. I’d cast these from wheel weights and powder coat them so they don’t plug the suppressor. Check out that BC. That’s why we don’t just run a common pistol round. Inside 100 yards the BC and accuracy isn’t a super deal. But they claim this thing will go to 600 yards. If it’s capable of 2moa at 600 that’s a huge deal.

I have a mectech in 460 Rowland. It’s quite the monster and if your just shooting 100 or so yards there would be no advantage above it.

With subsonics, there is virtually no advantage over a large caliber pistol cartridge carbine out to 100yds. What the .300BO and 8.6CM offer is the ability to do both heavy subs and lighter supers. Supersonic loads in something like the .44AutoMag isn't going to give you more than another 50yds. Whereas the .300BO gives you at least 200, if not 250yds, out of a platform capable of greater accuracy than your typical levergun. Not to mention much easier compatibility with suppressors. It ain't gonna be a do-all 400yd deer rifle but it does some things other options do not.

My interest would be more towards a light boltgun, than an AR10.

I found some info on the .338Spectre using softnose cast bullets. I see some commercial cast 200-250gr cast bullets. Also a very interesting option.