anybody use these have a pic of one on there gun im looking into buying one but do not know if it is worth it

Pig Tails arent really needed on a 16" gun. Extra $ spent on ammo is a better idea. What specific function problem are you having? Ive got an 11.5" upper on my M16.. It runs like a sewing machine without any xtra length in the gas tube area..

ETA: If you were running a really short bbl... Like a 7.5 or even a 6.5" ( Oly has those) then maybe you might want to consider.. IMO a pigtail gas tube wont improve the functioning of your AR.

nothing wrong with my ar shoots like a dream just wondering about them

Cool.. I had a problem with another gun a while ago. Specifically Q3131 in an 11.5" x 5.5" bbl.. Had FTE alot. But only with higher pressure ammo. I tried a pigtail.. Didnt do a damn bit of good. I ended up deciding it was a gas port problem and fixed the issue.

Thought maybe you were having a similar issue.

I have a pigtail on a 16" barrel.  It works as advertised.  I had to open the gas port.  It simply makes a 16 cycle and recoil like a 20.  It seems to slow the cyclic rate to the point that the gun returns really well.  I recommend them.

A pigtail gas tube is a "fix" used for rifles with cycling problems . Usually, these are experienced by those which use 11.5, 10.5 or 7.5 barrel lengths. The added length of the tube (because in spirals around the barrel) in a pigtail minimizes, if not totally eliminates, problems of bolt bounce or short stroking. [It has something to do with the amount of gas pressure blown back. I don't specifically understand the technical reason. I just know it helps.]

In your case, if your rifle does not suffer from these malfuctions, then you do not need to have this gas system.

If you have full auto capabilities, then as mentioned, the pigtail will reduce your cycle rate making your rifle more controllable in full auto fire. (But a brake is more the cure to any problem of controllability.) But, if you are only have semi-auto, then again, you do not need a cyclic rate reducer.

IMO .... other more learned and technical members may correct me if im wrong.

As said, if you don't have cycling problems don't install one.  If you want a gas tube that delays gas impulse, I recommend the PRI Fatboy instead.  I have seen sagging pigtails, but not Fatboys.  The Fatboys also reduce cyclic rate and ease extraction like a pigtail, and are easier to install (installs like any other gas tube).

If you want to reduce cyclic rate, skip all that and go with a good rate reducing buffer like the MGI.

Don't fix what ain't broke.

Quoted: As said, if you don't have cycling problems don't install one.  If you want a gas tube that delays gas impulse, I recommend the PRI Fatboy instead.  I have seen sagging pigtails, but not Fatboys.  The Fatboys also reduce cyclic rate and ease extraction like a pigtail, and are easier to install (installs like any other gas tube). If you want to reduce cyclic rate, skip all that and go with a good rate reducing buffer like the MGI. Don't fix what ain't broke.

+1

I happen to have both the Fatboy and the MGI RRB. Shoots even sweeter than it did before.