12.5" 6 ARC vs. 9" 300 BLK

[Vynz]

I think he’s using the hybrid case as a safety margin still loading to only 62kpsi and getting these velocities. If I was Sig I’d start making this ammo for the Spear submit to SAAMI and corner the market out from under Q both in ammunition and host rifle.

 

[45-90]

How did the 230’s run in that barrel?

I’m not bought into the 3 twist, but it may make sense for the subsonic stuff

the 230 gr bullets were longer taking up more powder space, so I wasn't impressed with the velocity at around 2200 fps, with the powder used...the 250s were 2200 fps and accurate.
I own a 3 twist, there is no up side compared to the 6.5 twist.
Subs and supers are more accurate, and the 6.5 stablize everything. In fact the 6 5 twist is over stabilizing bullets, but not as drastically as the 3 twist.
If an animal is 12" thick and the bullet revolves 2 times or 4 times makes no difference, plus it can stop spinning and tumble or veer off course at any time, and can not account for bullets varying behavior.

The 3 twist is a selling gimmick, but I had to try it...so I did.
300 SMK never shot so well as they do in the 6.5 twist.
A lot of experimenting with the 8.6. Such as pistol primers. But ran into trouble with one powder ...the velocity dropped from 741 to 482 fps on a pistol primers...creating a situation...does the bullet make it out the barrel on the next shot.
At these low velocities the 300 SMK is quiet and accurate in the 6.5 twist.
And finally a 50 test with the expensive 350 gr Maker bullets, many could not get them to shoot accurately, just change to the 6.5 twist no trouble their sub recommended load is spot on...but I can run it supersonic with no problems of bullet fragmenting in flight or inside the muzzle device...and the bullets cluster together as the powder charge jumps 1 gr at a time, with each shot.

Well that's my experience with the 8.6 Blackout, run the limiting 3 twist if ya want, but so a much better option is the 6.5 twist..in my experience.
On to other calibers, liking the 510 Whisper as of late.

 

[45-90]

Any interest in 375 Raptor or would you say 8.6 is where its at for a 308 based case?

I forgot I went with the 358 Win standard cartridge, in a short 16" barreled AR with Leverevolution 250 gr bullets were 2300 fps. It's pretty accurate...have shot it for awhile. It's the easy button.

 

[rlsmith1]

I forgot I went with the 358 Win standard cartridge, in a short 16" barreled AR with Leverevolution 250 gr bullets were 2300 fps. It's pretty accurate...have shot it for awhile. It's the easy button.

Did you ever shoot subs in that AR? I really like the 358 bore (happens to be legal for deer here too)

 

[45-90]

Did you ever shoot subs in that AR? I really like the 358 bore (happens to be legal for deer here too)

No, never tried subs in the AR 358Win, as I was running 500 gr subs in tbe 450 Bushmaster at the time.
I have a few 310 Woodleigh in 358, but 250 gr subs would be plenty for deer.
I'll put it on the list of things to try.

 

[vVexo]

He just dropped a video showing terminal performance between 300 Whisper and 10.5” 5.56 NATO, which was interesting. Velocity wins. Ballistics testing starts at 3:08.

This is why I’m excited about the new extreme high velocity 6.5 Grendel work going on.

Think about a 12” doing over 3340fps without pushing the pressure.

Bye-bye long barrels.

Where is the information on this “extreme high velocity 6.5 Grendel?” This is the first time I am hearing of this and it sounds like you have more to share. Thanks

 

[45-90]

Where is the information on this “extreme high velocity 6.5 Grendel?” This is the first time I am hearing of this and it sounds like you have more to share. Thanks

This video is unremarkable. ..high velocity always makes better wound channels in ballistics gel than subsonic velocity rounds.
When it comes to killing high velocity works much better there too.
Thats been known... forever.

The 10.5 " 5.56 killed alot of enemies in Vietnam/Cambodia and has a good reputation among many who used it.

The 300 blk out is more for stealthy head shots up close, the wrong tool to for comparison, like comparing a 300 mag to the 45-70.
I would choose the 5.56 as an overall general purpose defense round when SHTF.
One can run the 9 mm over 2600 fps in the AR 15 for a short range light penetration round...with a light 50 gr copper bullet...but I wouldn't choose it over the 5.56, cause it's range limitations...or run it over 3700 fps in 358 AR 10...but I'd still choose the 5.56.
The rounds are everywhere, even dropped rounds out in the woods where people plink. A good tool that works reasonably well is the 5.56.

 

[vVexo]

This video is unremarkable. ..high velocity always makes better wound channels in ballistics gel than subsonic velocity rounds.
When it comes to killing high velocity works much better there too.
Thats been known... forever.

The 10.5 " 5.56 killed alot of enemies in Vietnam/Cambodia and has a good reputation among many who used it.

The 300 blk out is more for stealthy head shots up close, the wrong tool to for comparison, like comparing a 300 mag to the 45-70.
I would choose the 5.56 as an overall general purpose defense round when SHTF.
One can run the 9 mm over 2600 fps in the AR 15 for a short range light penetration round...with a light 50 gr copper bullet...but I wouldn't choose it over the 5.56, cause it's range limitations...or run it over 3700 fps in 358 AR 10...but I'd still choose the 5.56.
The rounds are everywhere, even dropped rounds out in the woods where people plink. A good tool that works reasonably well is the 5.56.

I don’t think you understood what I was trying to ask. I want information on whatever this potential new 6.5 Grendel style round that is supposedly an “extreme high velocity 6.5 Grendel” per the guy I quoted. I haven’t seen any talks of such a cartridge currently being developed. I don’t necessarily care about the video he linked or its results. Just curious about that statement.

 

[45-90]

I don’t think you understood what I was trying to ask. I want information on whatever this potential new 6.5 Grendel style round that is supposedly an “extreme high velocity 6.5 Grendel” per the guy I quoted. I haven’t seen any talks of such a cartridge currently being developed. I don’t necessarily care about the video he linked or its results. Just curious about that statement.

Okay, only interested in a high velocity grendel...only way to get there in an AR is reduce bullet weight...
Here is an example 78 gr bullet for 300 blk 2700 fps...cut down to .264" it'd probably get close to your desired velocity in the Grendel.
They used to make these CQB bullets, but if they don't sell well they quit making them.

I make my own on a lathe...or cut down copper bullets to a certain weight, hollow point them, cut boattail, etc. To try to get the velocity you desire.
But most have to rely on industry to make their bullets...so you'll have to check around to see if something in the 60 gr area is available in 6.5.

 

[45-90]

So here ya go 12" Grendel high velocity load...do it yourself. Only takes a half hr to make the bullet and develop the load.
Machined 43.8 gr Hornady copper 338 bullet down to .264" cut to .758" long.
Leave the plastic tip of the hollow point on they are lighter than copper.
COAL 2.116" WIN 296 AND LILGUN are the powders.
12" Grendel = 3395 fps with W 296.
12" Grendel = 3412 fps with LilGun.
16" Grendel = 3681 fps with W296
16" Grendel =3684 fps with Lil Gun.
You definitely lose velocity in a short barrel.
But here ya go... do it yourself if no one makes what you want.
The 10" = 3210 VS 3684 for the 16" and the powder is not being consumed 100% now, as it was in the 16".