I have a 14.5" Colt (carbine gas) with a pinned and welded BCM Mod1 (1.5") compensator. I don't have a 14.5" mid length gas rifle to compare it to, but the recoil ain't bad. I've shot it back to back with 16" mid length rifles and can't really tell a difference in recoil. I'm not too recoil sensitive though.
I bought my 14.5" upper for a good price on Armslist without realizing I'd need to pin and weld a comp. After having it though, I'm glad I did. It is a handy, quick to shoulder rifle.

 

View attachment 345205 I have a 14.5" Colt (carbine gas) with a pinned and welded BCM Mod1 (1.5") compensator. I don't have a 14.5" mid length gas rifle to compare it to, but the recoil ain't bad. I've shot it back to back with 16" mid length rifles and can't really tell a difference in recoil. I'm no too recoil sensitive though.
I bought my 14.5" upper for a good price on Armslist without realizing I'd need to pin and weld a comp. After having it though, I'm glad I did. It is a handy, quick to shoulder rifle.

If a person is "recoil sensitive" with a 5.56/.223 caliber gun then that person should be getting a job as a ladyboy in Thailand.

 

IME, a well-built 14.5" midlength gun is an extremely pleasant configuration to shoot.

 

I have one each 14.5" in carbine and mid gas. The mid has been reliable, but I think I'd stick with carbine if it was a serious social gun.

 

I have one each 14.5" in carbine and mid gas. The mod has been reliable, but I think I'd stick with carbine if it was a serious social gun.

Why do you recommend the carbine length if the mid length has always been reliable for you?

 

Mid Length.

 

On 14.5" I would stick with the proven gas system.

 

Go mid. I've never heard anyone complain about the 14.5 in mid length.

 

There's a few people that I've seen online complain aboout 14.5 mid not being reliable with "weaker" ammo. Not sure how valid that is, or if it's one of those "I know a guy, who once talked to a guy, who's friend claimed to have issues", which is why I'm trying to get some opinions here.

 

A mid-length gas system, due to its longer length, has a longer dwell time and this slightly less gas pressure. This leads to a slightly smoother shooting carbine and it's a bit easier on parts. Given the option, I would always chose the longer gas system.

PSA sells some good parts. The CHF barrel is a great option, I love the lightweight barrel profiles. They balance well and swing well. A mid-length gas, lightweight barrel with a Bravo Company KMR would be my choice.

 

Unless it's over ported a Middy 14.5 is likely to be more picky with ammo.

A mid-length gas system, due to its longer length, has a longer dwell time and this slightly less gas pressure. This leads to a slightly smoother shooting carbine and it's a bit easier on parts. Given the option, I would always chose the longer gas system.

PSA sells some good parts. The CHF barrel is a great option, I love the lightweight barrel profiles. They balance well and swing well. A mid-length gas, lightweight barrel with a Bravo Company KMR would be my choice.

Dwell time is the length from the gas port to the muzzle. A carbine system will always have a longer dwell time than a middy at a given barrel length. It's why BCM started doing 11.5 barrels instead of 10.5 for SBR uppers, longer dwell time.

I must admit I have considered cutting one of my seldom used middys down to a 12.5 SBR just to see how it well it functions suppressed.

 

Oh I have the psa chf 14.7 FN mid length barreled upper, and it shoots really well even with cheap wolf. Running it with a std carbine spring and H buffer, very smooth shooter. I almost bought another just the other day when they posted them in stock, still resisting the urge. Get yourself a nice comp like the griffin flash comp to pin to the end and you will have no regrets.

If the gas port on the barrel is ported correctly with either length you should have no issues.

 

Is your PSA barrel the A2 profile, or the "A2 lightweight" that they offer?

 

Why do you recommend the carbine length if the mid length has always been reliable for you?

Because while the 14.5" mid has been reliable in recreational shooting for me, I think the gas system is not as forgiving as carbine in that barrel length.

 

Carbine system is designed for 14.5 barrels. Mid length was developed for the 16 inch barrels.
It's all about the distance from the gas port to the barrel crown. A 14.5"carbine a 16" Mid-length share the same cork time.

 

This is the correct answer. Midlength systems were designed to overcome carbine length problems on civilian legal 16" barrels. I own a 2007-vintage CMMG midlength 14.5 and it does have problems with lower power ammunition (.223 loads, Wolf steel case) not cycling the bolt fully. Actual 5.56 loads cycle fine. On the plus side it is the softest shooting of any AR I've ever used.

 

Thread hijack. If you have to have 16" length why not go all barrel instead of the muzzle brake? Is it a weight issue?

 

Little bit of weight. Little bit of length. Something a little different than the usual 16" set up.

And a little bit of a middle finger to the ATF/NFA :supergrin:

 

The total length is a little over an inch shorter than a 16". I know it's not that much difference, but you know it.

 

To me a 14.5" barrel should have a carbine gas system and a 16" barrel should have midlength gas system. In my opinion that is ideal, not that a different configuration wouldn't work.

 

Can you elaborate as to why you feel the 14.5" with a carbine gas system is ideal?

 

I'd run carbine length. It is the standard config in the 14.5" M4, so that should tell you something. If the recoil is a bit snappy, go to an H buffer.

 

I'm not really worried about recoil. I just see a lot of options from multiple manufacturers offering 14.5" with mid length gas systems.

 

I have 2 BCM 14.5 lightweight uppers with the midlength gas system, haven't found any ammo they won't shoot yet........100%reliable so far.

 

Often forgot about in these discussions is the various gas port sizes that have been drilled, it only takes a very small change in size to effect the overall system. Brings me back to my childhood day's and the story of a little girl & 3 bears...

 

Depends on the brand.

BCM 14.5" middy runs fine on decent ammo. Carbine gas is more reliable with nasty ammo. Good rifle with good ammo, go middy. Cheapo rifle with cheap dirty ammo, go carbine gas.

 

Depends on so much more than just brand of ammo. Quality of ammo, weight and velocity, what buffer and spring, what carrier and what is your purpose.

Most people have no need or desire to shoot 6 rounds a second on close targets with no sight movement, so the effect of a flat shooting rifle makes no sense to them. Most people have no need or desire to shoot at small targets at 300 yards and be able to see the bullet impact either.

My 16" carbine gas rifle runs 40-50 grain bullets at around 2250 fps, it is soft and flat with that load. My 16" intermediate gas rifle runs 69s at 2850, it is soft and flat with that load. But neither will run the other load well.

A well tuned 14.5" rifle with mid-gas is a pretty nimble and fast option when all the other parts are correct to have a good tune. I really like that set-up for 55s just at the crossover from commercial to NATO pressures. Accurate and pretty soft allowing me to still double at 40 yards and keep the spread inside of 4". I could never double a carbine gas 14.5 and maintain the sight picture to split in the 0.12 to 0.15 range. Had to wait until it resettled, which resulted in .4 to .5 splits. The longer the gas system, the longer the barrel will last and the longer the gas rings will last, but again, most people don't shoot enough for that to be an issue.

 

Some great info in this thread......

 

I have a 16" mid and 14.5" mid and both can run cheap, crap ammo just fine. I only tested with 40 rds or so but I wanted both AR's to shoot anything on the market, including the worst types. I mostly shoot XM193 or XM855 ammo though.

 

I recently bought one of PSA's 14.7" mid-length A2 profile CHF uppers. Works well with PMC .223 Bronze, LC XM193, and Speer .55gr Gold Dot .223. I have some Wolf 55gr steel cased on order that I'll try this weekend. If they offered a carbine length with free floated rail, I would have probably gone that way. But, I think I will be happier with the mid-length.

 

While I would agree that that is currently a fairly accurate statement today, it's wasn't 15 to 20 years or more ago. There wasn't a mid-length gas system offered years ago, only carbine and rifle lengths if I recall correctly. Stoners original 16" barrels I recall were only offered in carbine length gas. Mid-length is a recent development compared to the over history of the platform.

 

I seem to recall Armalite was the first to offer midlengths commercially back in the 90s at least, but they were definitely not the norm. I didn't build my first mid until about 10 years ago.

 

The carbine gas system was not designed for 14.5" barrels. It was designed for 11.5" barrels.

 

Which setup allows a bayonet to attach correctly?

That's what's important...lol

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I seem to recall Armalite was the first to offer midlengths commercially back in the 90s at least, but they were definitely not the norm. I didn't build my first mid until about 10 years ago.

That is a true statement for sure as I owned one back in the late 90's, at the time I don't recall hardly anyone else using mid-length. The mantra of the day it caused more issues than it solved, funny how times change.