13.9 vs 14.5, same profile

I would say you'll notice .6" of difference in length. Maybe 10fps. Maybe 41fps. Maybe the 14.5" will actually be slower.
They might both shoot poorly.
Also, assuming they are both getting pinned to 16", there will be no functional difference in overall length.
 
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For OAL with a suppressor, your mounting system is going to matter. For instance, with Griffin Plan A, the muzzle device to take a 13.9 to 16” is longer than the device for a 14.5 in the “neck” area, not the mounting surface. What this means is that with an identical can attached to two rifles, one a 13.9 and one a 14.5, the OAL of the 13.9 with a can is only like .1” shorter than the 14.5. So in that situation, it doesn’t make a ton of sense.
 
I had assumed they were both Middy’s but just didn’t feel like looking it up. I know if they’re both .076” ports then they’re both gonna shoot nice and soft, with the 13.9 shooting even softer, obviously. I wouldn’t worry about velocity diff with only .6” of length diff. Flip a coin?

And 650 is pushing it with a 5.56, as far as WEZ analysis is concerned. It can do it, sure. Can it do it well? No
 
I believe due to if you are gonna P&W it, its the shortest possible OAL while still being legal.

Also, it does indeed shoot a bit softer than a 14.5.

A buddy has a 13.9 BA Hanson, I believe it is, and it shoots damn good and soft.
 
Not a great benefit in weight and handling, and then the tax stamp and about 50 fps loss, keep in mind with 223/5.56 every inch you cut off from 16 is a case of diminishing returns, the fps loss can get drastic eventually creating a fast 22. 14.5 is about as low as I would go, I have one and do enjoy it.
 
Not a great benefit in weight and handling, and then the tax stamp and about 50 fps loss, keep in mind with 223/5.56 every inch you cut off from 16 is a case of diminishing returns, the fps loss can get drastic eventually creating a fast 22. 14.5 is about as low as I would go, I have one and do enjoy it.
Maybe. Maybe not. I've got a fleet of 14.5" barrels. I've got one 13.7", and it averages 75fps slower than the fastest 14.5", it's the same or slightly faster than the slowest 14.5". What does all this mean?
Nothing.
Just like .6" worth of barrel is likely to.
 
For OAL with a suppressor, your mounting system is going to matter. For instance, with Griffin Plan A, the muzzle device to take a 13.9 to 16” is longer than the device for a 14.5 in the “neck” area, not the mounting surface. What this means is that with an identical can attached to two rifles, one a 13.9 and one a 14.5, the OAL of the 13.9 with a can is only like .1” shorter than the 14.5. So in that situation, it doesn’t make a ton of sense.

This is such amazing information, how I never thought of it/noticed it before, I don't know. I've agonized over that length difference and I have both. My 13.9 has a Griffin FH 2.75 and the 14.5 has a Griffin Stealth FH, both p/w - top picture is the neck, there is some difference in tine length as well.

FH275

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STEALTH FH

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I hope this helps someone else!
 
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This is such amazing information, how I never thought of it/noticed it before, I don't know. I've agonized over that length difference and I have both. My 13.9 has a Griffin FH 2.75 and the 14.5 has a Griffin Stealth FH, both p/w - top picture is the neck, there is some difference in tine length as well.

View attachment 8522129
View attachment 8522130
View attachment 8522131
View attachment 8522132
View attachment 8522133

I hope this helps someone else!
Glad it helped. I’m still going to do a 13.7 anyway, even though I have the 14.5 too 😂
 
none of it really matters

personally I go 11.5" MASTER RACE for everything I can

sometimes it is nice to go with a rifle length gas system as god and stoner intended because it is so smooth in its operation

unless you are in and out of vehicles all day long with your rifle then you should be able to make any length 18" and under work just fine even suppressed
 
I put ARs together as a hobby that I've been into for the last 20 years. I literally have over a dozen upper receivers laying around and a bin of barrels. I get an idea in my head and I'll go out to my garage and put it together. I bought a small welder and pin and weld my own stuff.

What I've found is that the velocity difference among 13.9, 14.5 and 16" is negligible. It has no noticeable impact down range. The velocities usually run within 100 fps of each other.

What it comes down to is how obsessive you are about getting as short as you can without having to pin and weld, run a brace or SBRing it.

The most practical setup is a 16" and you'll thank yourself every time you decide to try a new muzzle device, gas block or handguard. A 16" with a standard A2 flashhider is still pretty short and slick handling.

If you've just gotta have the shortest possible, then it's all about the muzzle device. If you're gonna run something longish, like a NOX, then go with a 13.9 (13.7 can be a pain in the butt finding a muzzle device). If you're just gonna run an extended A2, then 14.5 makes sense (14.7s are cool because a standard A2 will pin and weld to 16").

As for the 12.5, I don't know. Just looking at it, it's really close to a 13.9. I'd say, if you're gonna run suppressed, go 11.5 and run a brace. I have a 13.9 and 12.5 and when they're both standing next to each other, it's hard to tell them apart.

I don't have a 16" put together right now because I like things as short as possible. I do my own welding so it's no big deal to me. My SPRish rig is a 14.5 with extended A2. My goto rig is a 13.9 with a NOX no mount muzzle device. I also have a 12.5 that I'm running because it's more accurate than the 11.5s that I have, but it's getting chopped to 11". I want to see how it's gonna run splitting the difference in dwell time between 10.5 and 11.5.
 
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