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In the gilded halls of Valhala
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Discussion Starter · #1 ·
New caliber available for ar-15s.
https://www.facebook.com/W3PrecisionSystems

I will post the link and some photos. Saw this elsewhere, but wanted to discuss here.

Can't wait to see some ballistic data.

its a .308 case chopped and necked for .375

here it is next to a .300 blk out


fits in ar-15 regular mags. you'll need a new bolt of course. 15 shots per mag.


this would make a good camp rifle?

43$ gets me 50 .375 gr hornady GMX bullets. brass is made using .308 brass and existing dies.
 

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As a 300BLK owner and fan, I'd love to see more details on this round. looks like an AR upper build would be similar to doing a .50 Beowulf, given the size of the case. I'd be most interested in seeing the bolt design, how it locks up, etc., and what else has to be modified from "straight" 5.56 rifle parts. I'm currently accumulating parts for a 6.5 Grendel upper, maybe this .375 can be the third.
 

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In the gilded halls of Valhala
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Discussion Starter · #3 ·
i hope this is not like the grendel when it comes to magazines. it looks like the feed lips are unmodified though so thats good.

Hopefully there will be a barrell + bolt package deal thats affordable.

if it gained traction and projectiles were made for it, i think it shows promise.

One problem is the smallest .375 are still 250-300 gr projectiles. some .375 bullets would fill the whole case.

let me ask you, do you crimp your .300 aac loads? I have plenty of neck tension they are just seated so shallow im considering crimping them.

I chambered one after a "bump in the night" when i got sent to check out the noise... damn thing came apart in my action during extraction it was a mess.
 

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i hope this is not like the grendel when it comes to magazines. it looks like the feed lips are unmodified though so thats good.

Hopefully there will be a barrell + bolt package deal thats affordable.

if it gained traction and projectiles were made for it, i think it shows promise.



You beat me to it Dresden. Shucks.
Yeah, i wonder what the ballistic data looks like.
Anyone with info on that yet?

Deuces
 

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let me ask you, do you crimp your .300 aac loads? I have plenty of neck tension they are just seated so shallow im considering crimping them.
I don't crimp them; I haven't had any issues yet, but I agree, it doesn't seem like there's much to hold them in place, although the bullets I normally use seat to the start of the boattail (meaning the taper of the boattail is past the neck). I'm only using cut-down 5.56 LC brass, and haven't bought any factory ammo for mine. I use RCBS dies, and I seat 155's to 2.150 and 125's to 2.100. I don't shoot subs much, but the 200 Nosler and 220SMK's I have loaded go to 2.200.

The .375 looks to be a good subsonic platform. The big-ass bullet will take up a good bit of case volume, and even though it's substantially bigger in diameter than the 300 BLK case, the shortened .308 case will be limited in powder capacity to move it at anything past 1500-1750 fps, I suppose. Sort of like a scaled up Blackout. My concern would be the lockup lugs on the bolt. The .308 case head is large enough that to use something the same diameter as the 5.56 BCG would require fairly thin locking lugs, so I'd worry about compromised strength. The .50 Beowulf uses a rebated case rim, which avoids this to some degree. I suppose going to fewer lugs on the bolt and breech face might be one way around it, but then the bolt rotation on lock-up would have to change, which would require modifying the carrier as well. The true beauty of the 300BLK is the complete use of 5.56 parts except for the barrel.

Is this truly designed for the AR15/M4 platform? Seems like the AR10 would be a natural, since it's a .308 anyway.
 
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In the gilded halls of Valhala
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Discussion Starter · #8 · (Edited)
i ran some numbers for fun...

keep in mind this is just me playing with numbers i made up.

with a barnes tsx and an arbitrary fps of 1950 (though some say 2200 may be possible) i got this:



this is the actual dope from a load i shoot in my ar pistol 8.5" (.300aac) for comparison:



and here is a long range fantasy load i have yet to try (cant find the projectiles)
 

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In the gilded halls of Valhala
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Discussion Starter · #9 ·
i didnt know you guys made bullets!

i love my bolt handle. .
if i could go back id have bought the w3 over the aics.
 

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In the gilded halls of Valhala
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Discussion Starter · #10 ·
according to my program your projectile flies 200fps faster than the berger at the 800 yard mark. (assuming .5994 bc g1 drag
 

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yep.....check this guy's testing on the link below and you can see his speeds. It's crazy.....
That's really impressive. Not the least because anything over 19.5 gr of AA1680 in a LC brass 300 BLK is a compressed load for any bullet over 150 grains seated to 2.200. Loading 24 grains, it's no wonder the velocity increases so much over 23 grains. I'm almost surprised he can even seat the bullet at 2.400. I seated a few 155 Palma MK's at 2.200 with 20 grains AA 1680, and it sounded like crunching potato chips as I seated the bullet. I wonder what chamber pressure is at those loads.
 

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Im digging this new round Dredsen!!! Sounds like a great hog cartridge up close, I would hate to get nailed with it thats for sure!!!
 

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In the gilded halls of Valhala
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Discussion Starter · #17 ·
I would love to get a bolt and barrel when one becomes available. Maybe I can convince someone local to take a feral pig with it so we can see how the rubber meets the road.

I'm happy because my home defense ar will double as a guide gun/camping gun. It's a great notion.


Would that 200gr game king be good for grizzly? Or rutting moose?

If not maybe use a side charging upper. It would be a single shot , but you could use heavier bullets.

I know there are some good loads for .300 blackout that simply won't cycle in an AR.

We're the tests out of an ar or a bolt gun?
 

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clip...

The .375 looks to be a good subsonic platform. The big-ass bullet will take up a good bit of case volume, and even though it's substantially bigger in diameter than the 300 BLK case, the shortened .308 case will be limited in powder capacity to move it at anything past 1500-1750 fps, I suppose. Sort of like a scaled up Blackout. My concern would be the lockup lugs on the bolt. The .308 case head is large enough that to use something the same diameter as the 5.56 BCG would require fairly thin locking lugs, so I'd worry about compromised strength. The .50 Beowulf uses a rebated case rim, which avoids this to some degree. I suppose going to fewer lugs on the bolt and breech face might be one way around it, but then the bolt rotation on lock-up would have to change, which would require modifying the carrier as well. The true beauty of the 300BLK is the complete use of 5.56 parts except for the barrel.

Is this truly designed for the AR15/M4 platform? Seems like the AR10 would be a natural, since it's a .308 anyway.
I was thinking the same thing. If you used an AR10-type to start with, you could use the AR10 bolt and magazines (assuming OAL wasn't too short for reliable feeding). But then maybe there are other issues I'm not aware of. I've only worked with 5.56mm and 300BLK to date...I need to get with the times and get a .308...
 

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I use IMR 4227 in a T/C for a 30 Herrett load. The 180 grain boat tail round flies out of the 10" barrel at about 1850 fps with an impressive muzzle flash. This is essentially a compressed load and I would not really consider using more of this powder to speed things up a bit.

Nelson
 
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