I think myself if I should change the standard gas tube of my 14,5" semi-auto M4 to a PRI Fat Boy Gas tube.

http://www.pri-mounts.com/mm5/graphics/images/05-0050.jpg

I use a H-buffer and a standard recoil spring.

Makes it sence to change?  I dont't want to overbuffer the rifle, so it failures to hold open the bolt on the last shot.

Any hints and/or experiences with the Fat Boy?

what's the problem with your standard gas tube? isn't the rifle reliable?

Does this rifle have a suppressor?

The Fat boy can cure a carbine that is overfunctioning, but on the other hand it can cause a carbine to underfunction as well.  Don't use it if you don't have a problem.

If your carbine overfunctions there are cheaper solutions you should try first.

I bought one to throw on a gun with a muzzle mount suppressor, just because I felt that if the can is always there, the gun will always be overgassed - why not.  

Without an overgassing problem I would stay away, your rifle might not function with it.  (If you can afford to try it out, go ahead.  

Stay away from McFarland one piece gas rings though as they will definitely not be functioning the rifle with a fatboy.  I had that problem once and it was tough to diagnose as I had so many different products working together on the same rifle.   (that's why it's also nice to add one product to the "STOCK" weapon at a time, so if the gun stops running properly you know exactly what the problem is.  

no problems, no need

I have one on my 14.5" bushmaster upper. I actually tried it with the standard and with the Fat Boy. For me I can take follow up shot faster with the Fat Boy, it seems to soften the recoil a bit.

About 1500rnds through it without any failures.

If you buy one and don't like it, I'll trade you a standard gas tube for it...

Quoted: FAT BOY GAS TUBES ARE PRETTY NEAT ON 11.5" AND 14.5" UPPERS. VERY SOFT GAS PULSE, LOWER CYCLIC RATE, YET RELIABLE. I'VE NEVER TRIED ONE ON A 16". THEY WILL KEEP A 10.5" FROM RUNNING, THOUGH. THESE HAVE NOT BEEN MADE IN YEARS. CURRENTLY NOT AVAILABLE, AS FAR AS I KNOW.

That's a shame!  Any idea if PRI will ever make another run of them?  Been running one (bought from MSTN!) on a 16" carbine since they were introduced years ago.  No problems whatsoever, gun runs like a champ with everything I throw at it.

Lower ROF, lower recoil, less pressure and not as hard on the bolt and other small parts = longer parts life.

Thanks a lot for the numerous answers!!!

I have a McFarland one piece gas rings and no supressor, a Troy Medieval muzzle device on a 14,5" chrome lined RRA-barrel,a H-buffer and a standard recoil spring...and no problem with the funktion!!!!

And to keep this nearly perfect reliability, I will leafe the system without a Fat Boy!!! hanks

BTW, can someone explain me, where I can see if my carbine is overgassed?

GreenO

Tell us more about McFarland ring problems.  I have them on my suppressed AR10T, and it sure hiccups occasionally.  Did I goof?

Quoted: BTW, can someone explain me, where I can see if my carbine is overgassed?hr

If your carbine is overgassed you might have FTE's (failure to extract case from chamber as extractor slips out of  case groove)