Interesting video, and a followup to his prior interview about 9mm ballistics and the path the FBI took with handguns over the years. I'm only partway into it and looking forward to the rest. I'm calling it for 11.5" with a projectile in the 70ish grain range, but I guess we'll see.

“Best” for what purpose?
I probably won’t get around to watching it myself, so please let us know.

The "tl;dw" starts at 12:54, but yes, "for what purpose" is something he responded with plenty. For law enforcement and the US citizen wanting the right rifle for defense purposes, it's an 11.5" with a 1-7 or 1-8 twist moving a 62-75gr bonded bullet. James asked about out to 100 yards and that was the answer. He asked about out to 200 and the guy didn't even hesitate, just immediately "11.5." Out to 300 and beyond, the answer was 18", which was interesting to me that he skipped over 14.5" and 16" as the other common "sweet spot" stopping points in the conversation. Yes, 16" is the shortest it gets in a rifle without the paperwork, which neatly skirts the "AR pistol" conversation, but he said for those willing "to do the paperwork," the 11.5" was what they've settled on. James asked about the recent rash of 7" offerings (the SCAR 15P springs to mind) from Euro manufacturers and he said that would probably be sufficient if the use case was basically handshake distance out to about 75 yards.

Thanks.
I could offer my own opinions about muzzle blast and terminal ballistics, but I won't.

quote:

Originally posted by P220 Smudge:
For law enforcement and the US citizen wanting the right rifle for defense purposes, it's an 11.5" with a 1-7 or 1-8 twist moving a 62-75gr bonded bullet. James asked about out to 100 yards and that was the answer. He asked about out to 200 and the guy didn't even hesitate, just immediately "11.5." Out to 300 and beyond, the answer was 18", which was interesting to me that he skipped over 14.5" and 16" as the other common "sweet spot" stopping points in the conversation.

He didn't skip 14.5, instead specifically mentioning it as a good option for 200-300 yards.

He doesn't get up to 18" until talking about a "Designated Marksman" taking a 300+ yard shot.


Also, just because an 11.5" barrel will still get you up to an optimal velocity for defensive ammo out to 200 yards doesn't mean that a 12.5, 14.5, or 16" barrel won't. The added barrel length just isn't strictly necessary for that required velocity. (And you don't want a really overly long barrel that will push the velocity up past the optimal range for that bullets performance, but that isn't going to happen with a 16" barrel...)

For example, if you want the absolute shortest barrel that can still get you that optimal velocity window within 200 yards it's 11.5. But if you don't want to mess with SBRs/pistol braces, so will a 16". Shorter and lighter is generally better, but there could be other factors that outweigh that.

Therefore this shouldn't be interpreted as a call to ditch all your 14.5/16/18/whatever guns and run out to replace them all with 11.5s. It just means that if you do go with an 11.5 you aren't giving up anything in sub-200 yard performance, and 99.99% of LE and citizen defensive scenarios will be well within 200 yards anyway. So it's worth considering an 11.5" on your next rifle, or your agency's next batch of rifles.

quote:

Originally posted by sigfreund:
Thanks.
I could offer my own opinions about muzzle blast and terminal ballistics, but I won't.

I have a Maxim Defense 5.56 with an 11.5
I'll sum up the muzzle blast in a word:

Fuckin' Obnoxious!

Even with a Griffin Armament Blast Shield.

So, extrapolating,
a Federal American Eagle .223 Rem 50gr Tipped Varmint round

from a 20", 1:7 twist Colt Sporter Match HBAR

at in-home #6 birdshot distance,
won't penetrate the Moroccan home invaders more than an inch deep

but will 100% skin them alive.



Seems reasonable.

_________________________________

quote:

Originally posted by sigfreund:

I probably won’t get around to watching it

Good call. It was kind of pleonastical.

quote:

Originally posted by CPD SIG:

Fuckin' Obnoxious!

Without a suppressor, they are Fuckin' obnoxious.
Take them indoors, they are ridiculously Fuckin' obnoxious.

I have a few 11.5" 5.56 rifles. IF I had it to do again, I might own one 5.56 with a 11.5" barrel. Everything else with barrels under 14.5 would be in a caliber other than 5.56.

Good thing I went with 12.5", just out of spite.

The unacknowledged elephant in the room:

quote:

Originally posted by Jupiter:
Everything else with barrels under 14.5 would be in a caliber other than 5.56.

Although it lacks the penetration capability and long range usefulness of the 223/5.56, even the 300 Blackout (not to mention other cartridges) delivers the same muzzle energy from a ~9 inch barrel as most 223 loads do from 16 inches. And with a lot less obnoxiousness. If short is sexy and more convenient when checking someone’s bedroom closet, why not do it all right?

But I’m not qualified to render such opinions, so disregard all that.

If your taking 200+ yard shots for “home defense” your going to have some explaining to do.

I guess I can’t commit to a length. I have 5.56 guns in 10.5, 11, 11.5, 11.8, and one on the way in 12.

It's cute, makes for an interesting discussion, but it's impractical. Most gun owners will never get anywhere near the NFA Registry, and the 16" carbine is by far the most common AR barrel length. The 14.5/14.6" barrels with a pinned and welded muzzle device to attain 16" length is about as short as most AR owners will get.

Yes, there are AR pistols with 11.5" barrels but they are classified as pistols because they are a compromise in the way these firearms are stocked.

Aside from compactness, there is no advantage of the 11.5" over the 16" and the 16" has the ballistic advantage, not to mention optimum (mid-length gas system) or close to optimum (carbine-length gas system) dwell time.

For general kicking around I like a lighter-weight 16” barrel. It kinda makes sense that if the video mentions the 11.5” for modest ranges, then the 18” for the longer, there’s room for the 16” in the middle.

Of course personal preference factors in heavily. Many like the simple purchase of the ‘rifle’ version.

I was plinking not long ago with another shooter, 50-75 yards. His 16” AR from PSA did just fine.

One other thing, most of us aren’t in the FBI. We are more likely to be casual shooters, plinking, hunting, varmint control with HD mixed in.

Once the FBI standardized on the 11.5" and a 64 grain round, I followed suit. My target is man sized, at the same distances I'd expect them to engage in. I'll let their research work for me.