Recently I burned out my 10.5" BBL (PSA - 11,000 rounds - it had a long life).  And based on various endorsements I decided to replace it with an 11.5" Barrel.   At least with PSA, they use the A2 configuration, so the extra inch is HBAR thick steel, and I can feel the weight addition - adn don't like it.  I'm seriously considering pulling the 11.5", and mounting a 10.5" again, for the more handy configuration.  But I did do some testing with the 11.5", and have velocity data, from zeroing it.  Here is the comparison.



Hate to admit it, but that velocity difference is actually pretty substantial.  55 FMJ went up from 2585fps at 10.5" to 2700 fps in the 11.5".  That's kind of a big deal.  Especially since 2700 is the nominal "magic" velocity for 55 FMJ fragmentation.  Yes, I know I know, that number is hardly in stone, and that velocity falls fast as soon as in flight - but all the same...  It kind of gives pause to my plan on yanking off the 11.5"

FWIW, I don't run suppressed, so the difference of a bare barrel going from 10.5" to 11.5" is more substantial than changing a 16" equivalent system with a big goofy bulb-thing at the end, to a 17" equivalent system with a big goofy bulb thing on the end.  10.5" bare is HANDY.  And 11.5" is just enough less so, to notice.  I'll say, this, ever since I got my RDB at about the same time as the BBL switch, the RDB is shorter, and more pleasant to shoot, yet has 17" of Barrel.  So I really almost never run this 11.5" gun anymore.  

So I guess I need to think about this some more; there's a trade-off either way for the non-suppressed, going from 10.5 to 11.5.  But that velocity and power difference is actually kind of substation, for just 1 more inch...  

Hmm...

You know, you can get a lighter profile 11.5” barrel. Like an ELW from BCM, BA Hanson or Faxon gunner or pencil

I did look.  I really like FAXON in general, but they tune their short ones for suppressed usage, which I don't do.  Might look at the other brands though - thanks.

Not sure what ammo you are shooting but both of your barrel lengths are about 100 - 200 FPS less than my testing.

For instance Lake City M193 from 2018 gives me

2715 from Colt Socom cut to MK18 and 2867 from a BCM 11.5

In the big thread with all of the velocities by barrel length, that data is what led me to a 12.5".  
If I remember correctly, there was a big velocity jump from 10.3" to 11.5" when using light weight ammo like M193, but not as much for heavier ammo.
However, there was a really big jump in velocity when going from 10.3" to 12.5" for 77gr rounds, but there was not a huge jump when going from 11.5" to 12.5" for lighter rounds.

I'm surprised to see how big the jump was for the heavier ammo.  

Good info.

Could be lot to lot variability and just test variability of the day.  That 77 velocity in the 11.5 looks to be a pretty high, especially since that 73 is supposed to be pretty hot.  I'd read more into the trend than any particular datum.

Good post.  The balance with the PSA 10.5 is it's a very high quality cost effective barrel, and the amount of goofy A2 barrel length is quite short, so as to not be so bad since most of the barrel is skinny (A2 before the gas port).  But add a whole other inch of thick diameter heavy HBAR steel after the gas-port by going 11.5, and it shows up.  I can feel it for sure.

As to Garand Thumb.  Sigh - I could ramble on for a bit.  I didn't watch it completely as I haven't found the block of time to listen to and watch an audio video.  And am just irked enough, I don't know if I'll devote the time.  I have skipped through it though.  

Let's just say I actually have a lot of respect for him and know he has the acumen and recognizes the priority of providing quality information that is used for people making assessments and decisions.  That video was frustrating because it was done so right on so many levels, and then he blew it.  And whenever Garand Thumb does that - everyone just writes it off as "oh that's OK, he's just entertainment".  No he's not, he built a following of millions of followers who pay for his lifestyle and service; and he did that not by just cracking jokes, but by being someone with a grounded balanced and intelligent assessment while giving the guns an actual work-out.  He very much is an assessment authority and people make decisions based on his work.  And he knows that - despite his dodging under "no no I'm just entertainment", wuss out he does when he blows it like this.   I value his opinions on things.  He's a blend of the best parts of Julian Hatcher (which is about as high a praise one can get btw - so if he reads this and swells - he should), combined with the best of the ethical parts of Larry Vickers, with a 1950's quality narration and enunciation and an entertaining delivery, while being just mortal and grounded enough to be relatable for people and not an insufferable ass (not that there's anything wrong with insufferable asses.  In fact, you should send your nearest insufferable ass cookies.  Good ones with the white chocolate chips and macadamia nuts.   Insufferable asses really like this!  Or... so I'm told).

What actually put him on the map for me was when he did some pistol tests that involved dropping the gun in the mud, stepping on it, and picking it up and shooting it.  A simple test that each of 15 guns.  It wasn't super repeatable, but it was subjective repeatable.  And it was interesting when he had a pause at the M&P shield passing it more than the rest, noting - he keeps seeing the shield doing that, even though nobody takes M&P Shield seriously.  I've noted the same, the M&P Shield are pretty underappreciated guns.

It frustrated me because his test design was only credible in a comparative basis, which he never did; but a spotty test for just a one-off test.  He basically machine-gunned a bare upper with no maintenance or lubrication or cleaning until it failed, and did so with thermo-cycling it to freezing after every too-hot-to-hold mag-dump (which is the 90 round mark; which you will learn REAL DAMNED FAST, if you ever get chance to do that with aluminum rail handguards like that).  It was an extended abuse application no one anywhere watching that video will ever actually do; so a race to failure mode no-one will ever actually have.  Akin to Lucky Gunner's infamous steel tests, which had failure rates far faster than anyone else, but did it on a 4X comparison basis, making it still highly credible and meaningful as a comparison tool of different ammo.  LuckyGunner got panned for that assessment, which IMHO, was an outstanding professional assessment test design, execution, analysis, and presentation.  I'd be proud to have been part of that.  Garand Thumbs?  I'd never mention to anyone I was part of this one.

Again, that's totally cool if running other known-quantities through the same test, but he didn't.  What killed me was he then had the gall to say it wasn't as good as a "higher tier gun" when it ran basically flawlessly for thousands of rounds of absurd abuse tests, that the higher tier guns were not.  The failure items were items that very probably would have failed on any other gun brand at those same Full-auto to cook then freeze - no lube no maintenance; repeat repeat; and are known consumables under such service.  

As to the barrel accuracy / copper issue.  Keep in mind it was a cheap bare barrel - and yet still did notably better than I was expecting.  I think it very possible that gun and barrel can be recovered to serviceable condition by replacing a few bolt-springs and a proper barrel cleaning.  The barrel had the hot-service cracking as typical in the throat area, but it didn't have fragmentation of that cracking or voids where pieces were falling out yet.  The rifling looked good, and the crown looked remarkably good.  

For reference, here's my 10.5 I retired at 11,000 rounds.  
Dirty (pre cleaning - though it had been cleaned along its life)



Post heavy cleaning

(with my apologies - I don't care for youtube's monopolistic and anti-freedom practices; but Rumble advertising aggression is insufferable as Hell)

Of note, in the throat, you can see the cracking has some gaps and voids where metal is starting to come out.  That's when a barrel is done and beyond repair.  Garand Thumbs barrel didn't have that - which is why I think it's just a large Cu Build-up, which is removable.  I've found when it's bad, aggressive scouring with a copper brush, Freeall and 30 or so patches of Cu++ (the gold bottle stuff), gets it pretty clean.  Then hit it with carb cleaner to blast all that out, and a light coat of modern gun-oil, then a dry patch to get the excess of that out.

I can assure you, unlike Garand Thumb, I don't actually make any money on this.  I would have hoped since he makes his livelyhood doing this, that he would have done a better job on that one.   The irony is he actually makes more revenue this way, since the buzz means more clicks.  Ah well.

Spikes Tactical has an A1 profile hammer forged 11.5" barrel.

It's lightweight, but its gas port is quite a bit larger than the 11.5" Daniel Defense, but I think the 11.5" government profile BCM barrel has a larger than DD gas port too.

I go with 12" but I roll my own. I cut down a 14.7 pencil bbl and drilled the gas hole .070

https://www.gmriflebarrel.com/GMRBItem.aspx?Item=GM-M64&ReturnURL=/military-barrels/ar-15-/-m16-/-m4-rifle-barrels&Category=2756c0ce-174b-46fb-bc11-6723e893d5ea

Yep. The BCM 11.5 is the lightest, then the Spike's, then Faxon, etc. CHF chrome lined and made by FN. The gas port is pretty huge so mine has a BRT gas tube. This configuration feels as handy as my wife's 10.3" with Geissele barrel and same Mk14 rail.