.300 AAC Twist - Best All Around?

I'm seriously considering a .300 blackout for my next AR build, especially since MI may be getting suppressors soon. Anyways, not sure what twist I should go with as I plan on shooting both sub and supersonic loads through it...found plenty as to which is best for each, but not so much for what works for shooting everything.

Will I find that I'm unable to shoot both types of ammo without accuracy issues, or is there a sweet spot that lets me run both types of ammo with good results?

Sorry if this has been discussed before, searching didn't get me far both here and elsewhere on the interwebz.

If you want to ever shoot the 220 gr rounds you need a 1-8 twist to stabilize. 1-10 will stabilize up to around 200 gr and might give you marginal velocity advantage but limits your bullet selection.

You aren't likely to find one barrel that will shoot both heavy subsonics and light supersonics well. You'll have to choose one or the other. I'd lean toward 1/8" for heavy bullets as that is what this round (300 Whisper) was originally designed for. It's hamstrung by low case capacity for supersonic performance.

Jack of all trades, master of none.

As far as subsonic goes, will the lighter heavy rounds be as quiet as the real heavy ones? Or is the only loss in energy delivered at the target? Completely new to subsonic stuff, my state doesn't allow cans so I'm not really up on it.

With a 1:8 twist, will the lighter projectiles not shoot well at all, or are we talking about a slight decrease in accuracy? Keyholing would be bad...but not too worried about a little less accuracy.

Can I 'make do' with a middle of the road twist rate?

Perhaps I can mitigate this issue right now...will the subsonic loads still have enough ass behind them to kill medium sized game, including two legged creatures, at 200 yards? I have a hard time believing it will however from what I've read some people say it will...

My main goal with this rifle is to have a 8-10" barreled upper plus suppressor (if we ever get the damn things) that would be good for hunting and possible HD use. For hunting (deer mostly) I typically mandate my rifles be good to 200 yards just in case.

Have any caliber specific projectiles been released for subsonic .300 AAC yet? From what I read that was part of the issue with performance at longer ranges...there just weren't any bullets designed to expand that slow.

So will I even need supersonic ability for my needs? I'm trying to read all I can but this stuff keeps updating so fast, and there's SOOOO much to read on the issue.

TANSTAAFL. There's No Such Thing As A Free Lunch.

However, there are compromises that just might get you the performance and flexibility you're looking for.

First, I think it's silly to build a rifle optimized for suppressor use when your state might someday let you have one. Just my opinion and if it stinks, please feel free to ignore it.

Second, the slower twist will shoot heavier bullets if those bullets are kept short. It's possible the standard twist will shoot bullets as heavy 180 -220 grains if a round nose is used. The 30-40 Krag will shoot a 220 grain round nosed bullet fine with it's 1:10 twist. Hornady lists loads as slow as 1600 fps. That's a bit more than than subsonic, but it's worth exploring as a long spire point doesn't offer much advantage at subsonic speeds and close ranges. The 30 caliber round nose also offers better performance and deeper penetration on game at slower speeds.

Do you need subsonic loads to hunt deer and defend hearth & home? No

1:8 is the best all around twist, as that is what we picked as the standard twist.

With shorter barrels and supersonic bullets and 1:8 twist, the lighter the bullet, the better the accuracy (110 is more accurate than 115, and 115 is more accurate than 125, and 125 is more accurate than 150).

The 8 twist is what most use. Short or long barrel.

1/8 twist it is, then. What sort of accuracy issues will I see with the supersonic loads? Anything real noticeable or keyholing or anything of the sorts? A slight loss in accuracy is perfectly acceptable all things considered. In either event I'll have to play around with some handloads when I get it and find a sweet spot.

As for whether or not this rifle is needed or not...it's my money, and I want it. Seems good enough for me. Besides, suppressors will likely be legal very soon, and even if they're not it'll still be a fun gun to have and shoot. I love taking my AR's out deer hunting anyways, makes the fudds' heads explode. I'm sure an AR pistol with suppressor attached would make for a good show :D

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Originally Posted by Joeywhat

1/8 twist it is, then. What sort of accuracy issues will I see with the supersonic loads? Anything real noticeable or keyholing or anything of the sorts? A slight loss in accuracy is perfectly acceptable all things considered. In either event I'll have to play around with some handloads when I get it and find a sweet spot.

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Not much if any. Remember that even 223 historically was a 1:14 or 1:12 twist. So people were all sorts of nervous about using 1:7 for 223 and of course it is no problem. I see fast twist as harming accuracy as 80% myth, 20% reality.

I was hoping it would be like that...I run a lot of 55gr through my 1:7 twist AR and it shoots reasonably well...certainly good enough for hunting.

On a related note, does anyone know if the major .300 AAC barrel manufacturers are going to make barrels in 4150 instead of stainless? Probably going to grab a Noveske barrel, but saw that Wilson had them as well...would really like black over the stainless, though.

I did notice AAC has a 9" barrel in some promo stuff, but couldn't find it in their store...

The AAC brand barrels are 4150.

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Originally Posted by Joeywhat

I was hoping it would be like that...I run a lot of 55gr through my 1:7 twist AR and it shoots reasonably well...certainly good enough for hunting.

On a related note, does anyone know if the major .300 AAC barrel manufacturers are going to make barrels in 4150 instead of stainless? Probably going to grab a Noveske barrel, but saw that Wilson had them as well...would really like black over the stainless, though.

I did notice AAC has a 9" barrel in some promo stuff, but couldn't find it in their store...

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The 9 and 16" barrel assemblies will be in the store online by tomorrow.

As Rob said, 4150, 1:8, nitride finish inside and out.

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Originally Posted by JasonAAC

The 9 and 16" barrel assemblies will be in the store online by tomorrow.

As Rob said, 4150, 1:8, nitride finish inside and out.

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Thank you, sir. I'll probably go for your 9" then, although it might be a few before I can swing for it.

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Originally Posted by JasonAAC

The 9 and 16" barrel assemblies will be in the store online by tomorrow.

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URL for the aac store?

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Originally Posted by chadbag

URL for the aac store?

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advanced-armament.com

Then for now, under "accessories"

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Originally Posted by JasonAAC

advanced-armament.com

Then for now, under "accessories"

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gracias

Thank you to everybody who added to this thread. It is full of exactly the kind of information I was looking for.

I am building a 300BLK M4A1(ish) carbine. Im going with a 14.5" black hole weaponry barrel. Which twist would be best? The 1x8.5 or the 1x11 twist. I will be using supersonic loads.

That is almost exactly the same question as

"I am building an 5.56mm M4A1(ish) carbine. Im going with a 14.5" barrel. Which twist would be best? The 1x7, 1x9, or the 1x12 twist."

Some people believe in getting the slowest twist that will stabilize the ammo you think you will be using (which would lead most people to a 1x9 twist for 5.56mm), and others say that you should be able to shoot all ammo (which would lead to a 1x7 twist for 5.56mm).

For 300 BLK, if you are 100% sure you will never shoot subsonic ammo, and don't care about resale value, then you can do 1x11 or 1x12 twist.

Or just get 1x7 to 1x8 twist to be able to shoot more types of ammo. Not sure what to make of 1x8.5 - don't see the point in fractions of a twist. Sounds noncommittal.

Ok, so the 1x8 will stablize rounds like 110gr v-max and the 123gr UMCs? If so that is what ill go with.
Cant wait for the UMC to come out.

Yes, 1x8 works well with those.

Is there a consensus on complete upper receiver manufacturer's quality for this caliber? I shot one a couple of weeks ago and may pick one up.

There are some I am not very familiar with, like the PWS.

The AAC and Noveske are the two best that I know of (I work for AAC) - and which you get depends may depend on which rail you prefer, if you prefer stainless or nitrided barrels, how you feel about each company, etc.

Thank you, I'll check out these websites.

Cheers