308 vs 300 blk

Discussion about rifles in 300 AAC BLACKOUT (7.62x35mm), hosted by the creator of the cartridge.

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hansonw
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308 vs 300 blk

Post by hansonw »

I'm talking specifically suppressed. What are the advantages the 300 blk has over the .308? Subsonic and supersonic.
kscarrington
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Re: 308 vs 300 blk

Post by kscarrington »

One of the most notable is the ability to run supersonic and subsonic, silenced or non-silenced, without having to run a gas block, as well as maintaing the ability to cycle the action. I have run subsonic .308 rounds through my RRA using the same silencer I use for my 300 BLK, and while it worked, it turned it into a 15-pound single shot.
hansonw wrote:I'm talking specifically suppressed. What are the advantages the 300 blk has over the .308? Subsonic and supersonic.
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Re: 308 vs 300 blk

Post by Quiet Riot »

The 300 BLK works in a standard AR15 that can accurately and reliably shoot both supersonic and subsonic ammunition. Most off-the-shelf 308 barrels are tuned for supersonics only and do not stabilize subsonics as well as an off-the-shelf 300 BLK.

Ballistically, 308 supers trounce 300 BLK, no question. You can even get some loads that approach the 30-06.

Subsonics in 308 and 300 BLK are exactly the same- same bullets, same velocity.
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hansonw
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Re: 308 vs 300 blk

Post by hansonw »

Sorry guys I meant to say for a bolt gun
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Hoop
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Re: 308 vs 300 blk

Post by Hoop »

hansonw wrote:Sorry guys I meant to say for a bolt gun
We are experiencing less than acceptable accuracy out of the 300blk in the AR15 platform with factory ammo. We are able to hold MOA with handloads if extensive case prep is done.

On a bolt action rifle, the .308 Winchester would be a better choice. You could run the same weight rifle from 800-1k yds and still work up a MOA or better sub sonic trail boss load.

Our shop 308 rifle is 18". I have MOA Sub sonic trail boss loads for both 180gr and 220 gr. bullets.
Throw in some LR308 ammo and its an 800yd + sub moa rifle.
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Re: 308 vs 300 blk

Post by robrob »

The two biggest differences between a .308 Win and 300BLK bolt gun are twist rate for subsonic and case size for supersonic performance.

The 1/7 or 1/8 twist of the typical 300BLK will stabilize 220-240gr subsonic bullets. A 1/10 .308 Win will stabilize 180gr bullets so a Blackout rifle will deliver more energy down range when shooting subsonics.

There is no comparison between the .308 Win and 300BLK for supersonic bullet velocity.

If I could choose only one bolt gun I'd definitely go with a .308 Win. I absolutely love my Ruger Gunsite Scout with its pre-threaded 16 inch barrel and 1/10 twist. I use 9.6gr of Trail Boss & 175gr SMKs or 9.8gr & 180gr Hornady round nose soft points for subsonic.
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hansonw
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Re: 308 vs 300 blk

Post by hansonw »

When the 300 blk started taking off I got an ar upper. I like it but I honestly use the 556 more. I have been waiting to get the model 700 sps in 300 blk. But I got to thinking that really that I would probably get more out of it if I got it in .308 just because of the supersonic advantages. But wouldn't sure if the .308 had any subsonic advantages. Basically I can't decide to wait to get one in 300 blk or go ahead and buy one in .308 instead.
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Hoop
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Re: 308 vs 300 blk

Post by Hoop »

hansonw wrote:When the 300 blk started taking off I got an ar upper. I like it but I honestly use the 556 more. I have been waiting to get the model 700 sps in 300 blk. But I got to thinking that really that I would probably get more out of it if I got it in .308 just because of the supersonic advantages. But wouldn't sure if the .308 had any subsonic advantages. Basically I can't decide to wait to get one in 300 blk or go ahead and buy one in .308 instead.
Same weight rifle, go with 308. No advantage to go 300blk since trailboss loads are accurate in a 308.

To get the accuracy you would want from a bolt action, you would need to hand load the 300blk anyway.

I have a factory Remington 700PSS that shoots 220 gr sub sonic ammo just fine. 1 moa
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Re: 308 vs 300 blk

Post by Tim McBride »

Hoop wrote:
I have a factory Remington 700PSS that shoots 220 gr sub sonic ammo just fine. 1 moa
I thought the PSS was a 1-12 twist? I haven't had a 1-12 .30cal barrel that stabilized 220's to any satisfaction.

As for the thought of a bolt gun, unless I had a short action, 223 bolt laying around, I'd just build a .308win with a 1-8 twist.
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Hoop
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Re: 308 vs 300 blk

Post by Hoop »

Tim McBride wrote:
Hoop wrote:
I have a factory Remington 700PSS that shoots 220 gr sub sonic ammo just fine. 1 moa
I thought the PSS was a 1-12 twist? I haven't had a 1-12 .30cal barrel that stabilized 220's to any satisfaction.

As for the thought of a bolt gun, unless I had a short action, 223 bolt laying around, I'd just build a .308win with a 1-8 twist.
The 220 I am using are the 30/30 looking hunting bullets. Exposed lead. I will get the model # soon. It stabilizes them fine. Same for the 180.

Not sure if the 220 SMK will work in mine. I will try a load.
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